IMIESA October 2022

PVC is the most effective and long term solution

PVC pressure piping production started in about 1935 and since then it has been through plenty of technical advancements which lead to PVC-O (Oriented Polyvinyl Chloride). Since the creation of PVC-O, it too has been through 5 improve ments over the last 40 years. Blue PVC-U (Unplasticised Polyvinyl Chloride), PVC-M (Modified Polyvinyl Chloride) and PVC-O (Oriented Polyvinyl Chloride) pressure pipes lead the potable (drinkable) water supply and reticulation market.

An upgrade of the R63 road from Fort Beaufort to Alice in the Eastern Cape is currently being carried out by Rumdel Construction Cape. P6

IN THE HOT SEAT

Setting a high standard for world-class toll road operations, Bakwena Platinum Corridor

Concessionaire manages the N1 from Pretoria up to Bela Bela (90 km) and the N4 from Doornpoort to the Botswana border (295 km). IMIESA speaks to Danie Verwey, Chief Technical Officer, about strategic planning, construction, and maintenance interventions. P12

Regulars

Editor’s comment

President’s comment

Index to adver tisers

Cover Story

Rumdel forges ahead on Eastern Cape’s R63 route upgrade

Africa Round-up

Infrastructure news from around the continent

Hot Seat

In expert hands, toll roads provide sustainable value

Industry Insight

Redefining road safety engineering in South Africa

Transportation

Assessing the impact of road provision on economic per formance

AECOM racks up experience from Ghana to Lesotho and beyond

Asset Management

Reducing non-revenue energy within municipalities

Industry Awards

Awards for excellence in consulting engineering

Geomatics

The issue of planning, ownership and plan approvals

Standards

Solar geyser local content requirements create jobs

ICT

Fibre bandwidth explosion in South Africa

Public sector must reimagine cybersecurity to enable e-government ideal

Roads & Bridges

Celebrating Brandwacht pedestrian bridge

Towards a sustainable asphalt and bitumen industry

Climate Change

Riverine management programme to assist with flood control

Environmental Engineering

Rehabilitating channels using a novel stabilisation approach

walls that retain the earth

Geotechnical

Why municipal projects should be wary of fine-grained sand

Thermoplastic Liners

Global lining solutions for large infrastructure projects

Infrastructure Funding & Implementation

Finding funds for water

Water & Wastewater

Natural pools – a water-friendly alternative

KSB calls for joint efforts to treat coastal waste

Pressure management for ozone water treatment

An alternative to concrete water storage 54 Data transmission of the pressure sensor signal

Innovation showcased on new Retreat pump station project

Ominous signs from hunger stones

Expansion into wastewater treatment

Vehicles & Equipment

Civils 2000 adds six new JCB backhoe loaders to its fleet

Delivering the asphalt for Phase I of Cameroon’s first expressway

Cement & Concrete

The first line of defence is protection

Stormwater revamp in Port Shepstone

New products enhance and protect concrete floors

Pervious concrete could reduce toxicity in urban run-off

INDUSTRY INSIGHT

We all know someone who has either lost their life or suffered a life-changing injury due to a road traffic accident. And yet when we step back and think about it, we realise that every accident is indeed preventable,

Verushka Balaram, Head: Road Safety and Design Investigations at ARRB Systems, who expands on engineered solutions.

KWAZULU-NATAL

NORTHERN

SOUTHERN CAPE KAROO

WESTERN CAPE

Why green mobility works

In 2020, fossil-fuelled transportation was the third-highest polluter, accounting for some 20.27% of total global carbon dioxide (CO2) emissions, according to Statista. The highest contributor was the coal-fired power sector, which generated approximately 36.51% of CO2 output, followed in second place at 21.74% by ‘other industrial combustion’ – essentially manufacturing and fuel production.

While other greenhouse gases like methane are a serious concern, CO2 dominates at close to 80% and jumped to its highest levels in 2021, rising by around 6% (36.4 billion tonnes), as reported by the International Energy Agency.

Just Energy Transition and EVs

It’s clear that a multipronged intervention strategy is required. These include initiatives like the Just Energy Transition, which protects economies and livelihoods during the progressive switch from coalfired to renewable energy sources.

Transportation is the next obvious sector, especially given the rate of urbanisation taking hold worldwide. The engineered responses will require intelligent and integrated transport networks that support the increasing roll-out of electric vehicles (EVs).

Passenger and commercial EVs are already making their presence known globally and will become increasingly more commonplace. For now, though, most EVs brands are priced at a premium. One of the cheapest passenger cars is the Fiat 500 Electric, with the 42 kWh version selling in the UK for around £30 645 (approximately R628 000). This car provides a driving range of around 320 km (combined cycle) and a top speed of some 135 km/h.

However, there are far more affordable options coming out of China that will help to bring down prices dramatically and boost the much-needed EV population. Examples include Changli’s Mini EV, which retails for around US$10 000 (around R182 000) with a top speed of 45 km/h and a maximum range of 48 km – fine for congested inner-city routes.

Moratorium on petrol and diesel vehicles

Globally, there’s a moratorium on the future manufacturing of new petrol- and diesel-powered cars. In the UK, the cut-off is 2030. Hybrids have a specified bonus extension to 2035. After that, all cars rolling out of UK plants, or imported, will be EVs. The European Union, in turn, has set a date of 2035 for petrol and diesel engines.

These are tough targets and not too far around the corner. They will also have a direct impact on South Africa’s vitally important automotive manufacturing sector, which has a major focus on overseas export markets.

On the other hand, it’s a great opportunity for South Africa’s Department of Trade, Industry and Competition to focus more on stimulating a vibrant EV industry that supports new jobs and industrial growth. We’re already seeing this gaining traction in the local renewable energy sector.

Public transport

Allied to its EV evolution, South Africa also needs to restore its commuter rail service as an essential and affordable public transport solution. According to the Department of Transport, there are plans to return to service 10 priority commuter rail corridors, three of which are in Gauteng.

For municipal bus fleets and the taxi industry, future green hydrogen and EV developments also have major downstream benefits, helping South Africa to achieve its net-zero greenhouse gas emissions targets by 2050.

Alastair

MUNICIPAL ENGINEERS ARE RESILIENT AND INNOVATIVE

When I was elected as the first woman president of IMESA in October 2020 for the 2020-2022 period, the Covid-19 pandemic was raging at full force across South Africa and the world.

This created a whole new set of challenges for me as an incoming president. However, it also presented an opportunity to steer IMESA through the toughest storm in its history, ably supported by an exceptional Exco team.

One of the prime examples was the successful launch of our traditional annual conference as a virtual event in November 2021. Co-hosted with the International Association for Water, Environment, Energy and Society (IAWEES), we pulled out all the stops using the latest information and communications technology (ICT) to reach a local and global audience.

However, nothing replaces an in-person event, and we’re especially pleased that our 85th annual conference held in November 2022 has been so well supported once again as a physical event.

A trail of devastation

The impact of the pandemic has certainly been devastating and we’re now in recovery mode as an economy and a society. So many jobs have been lost, industries like construction, aviation and tourism severely constrained, and some businesses forced to close their doors permanently.

Covid-19 has also highlighted some key social ills that were exacerbated by the crisis. Examples include the lack of adequate access to potable water, dignified sanitation and housing within the growing number of squatter camps surrounding our towns and cities. For these communities, the series of Covid-19 lockdowns and the need for strict hygiene measures were particularly trying. Plus, an already high incidence of unemployment was further exacerbated by the pandemicinduced economic meltdown.

To make matters even worse, the July 2021 civil unrest – predominantly in parts of KwaZulu-Natal and Gauteng – added to these challenges with the widespread destruction of infrastructure. Then a series of large-scale floods

occurred across South Africa during the first half of 2022, with regions like eThekwini among the worst affected. Damage to key infrastructure like bulk water and sewer mains left many residents without services for months.

At the other extreme, metros like Nelson Mandela Bay have had to endure some of the worst drought conditions in history as the city’s dams drop to critical levels.

An essential civil service

Throughout all this turmoil, the municipal engineering sector has remained resilient, forging ahead with essential projects. We’ve leveraged the benefits of ICT to project-manage and execute crucial maintenance and repair interventions in conjunction with our field service teams.

From the start of the pandemic, the focus for engineering team leaders has been on maximising health and safety – especially the mental health aspects for frontline workers, some of whom subsequently succumbed to Covid-19 in service to their country and communities. Our thanks go to every municipal team member for making a positive difference.

Going forward, South Africa’s Economic Reconstruction and Recovery Plan hinges on priority areas like energy security, industrialisation, macroeconomic stimulus strategies, and infrastructure development. The latter is the key to unlocking all these possibilities, and that in turn places major emphasis on every local municipality to ensure the most effective enabling environment in their region.

Ethics in practice

Backed by efficient and effective procurement and policy frameworks, the next few years could well be among the most exciting and rewarding for the municipal engineering profession. It’s a great honour and responsibility, requiring the highest code of ethical conduct.

For this reason, one of my key objectives as president has been to ensure that ethics becomes a compulsory component of the CPD cycle for registration with the Engineering Council of South Africa (ECSA). The proposal has been presented to ECSA and my hope is that it gains real traction. The infrastructure priorities are too urgent and, with constrained financial resources for the foreseeable future, the right financial decisions must be made based on fitfor-purpose engineering solutions.

Special thanks

On that note, I’d like to thank my Exco team, our branches, members and the IMESA head office staff for making my presidency such a rewarding experience. My best wishes go to the new incoming IMESA president, Exco and Council for the 2022-2024 period in taking municipal engineering excellence to new heights.

Bhavna Soni, president, IMESA

Rumdel forges ahead on Eastern Cape’s R63 route upgrade

Businesses and travellers alike are to benefit from the exciting upgrade of the R63 road from Fort Beaufort to Alice in the Eastern Cape, currently being carried out by Rumdel Construction Cape.

A ccording to Sanral, who commissioned the project, the new road will make for safer and smoother travel while reducing congestion. The work includes extensive use of concrete for structures such as bridges and culverts, for which AfriSam is providing its High Strength Cement.

The project’s scope covers the 23 km Section 13 of the R63, comprising 2.6 km of urban road running through the town of Fort Beaufort and 20.4 km of rural road. Alistair De Lacy, project manager at Rumdel

Construction Cape, says mobilisation of staff and equipment took place from July 2020, allowing work to begin in October 2020.

“We partnered with AfriSam for the cement for all structural elements of this contract, using mainly their High Strength 52.5N Cement,” says De Lacy. “This was suitable for the three new bridges, two bridge widenings, 12 cast-insitu box culverts and V-drains included in our scope of work.”

In line with the local procurement focus, a local readymix supplier was selected, who used AfriSam’s 52.5N product for the bridge pours

4 800 tonnes of AfriSam’s Roadstab Cement will be used for road stabilisation

and other applications. Some 4 100 m3 of durability concrete was poured for the bridges, 2 600 m3 for the culverts and 7 000 m3 for side drains and channels. AfriSam is also supplying its specialist road stabilising cement, Roadstab Cement, of which 1 300 tonnes are going into bypasses and 4 500 tonnes for the main works.

“We have had a seamless relationship with AfriSam through close communication at all times regarding supply,” he says. “They have been very helpful in ensuring that our programme requirements are met.”

Campbell Street

On the urban side of the contract, the work focused on rehabilitating Fort Beaufort’s main road, Campbell Street. This task went well beyond road work to include the widening of bridges and the rehabilitation of drainage, sewer and water networks.

“We reconstructed a 650 mm pavement with a 40 mm asphalt overlay, after replacing the sewer and water networks,” he says. “Adding

to the complexity of this task was marrying the new networks to the existing systems, which date back many years.”

Significantly, as per Sanral contractual requirements, Rumdel prioritised the engagement of ‘targeted enterprises’ – which are historically disadvantaged businesses –in conducting this work. With a budget from Sanral, Rumdel was able to train, mentor and closely supervise these businesses to achieve the required high standard of results.

He notes that the company has achieved an unusually high number of targeted enterprises on the project as a whole. By August 2022, over 70 of these businesses have been involved, and this number is expected to rise to around 90 by the project’s close.

Minimising disruption

Among the challenges was to minimise the disruption to local businesses and residents in Fort Beaufort, as well as traffic passing through the town en route to other destinations. A particular concern was to facilitate the movement of agricultural transport trucks, as the citrus picking season occurred during the roadworks.

“It was important to communicate constantly with residents and other stakeholders, making sure that everyone knew what our work programme was and how we were planning to accommodate them,” he says. “Our efforts to reduce disruption were supported by Sanral,

COVER

AfriSam is supplying its High Strength Cement for all the structural elements of the contract

To improve the R63 route, the road design has included extensive vertical and horizontal alignment

The urban side of the contract focused on rehabilitating Fort Beaufort’s main road

who agreed that we employ a revised layer works solution to put the main road back into service much quicker.”

To do this, the G1 base course was stabilised with an anionic bitumen emulsion, introduced with the on-site Wirtgen recycler linked to a bitumen distributor feeding at 38 litres per cubic metre with 1% cement. This allowed traffic to resume the day after installation, rather than waiting the seven to eight days normally required.

On either side of town, the bridges over the Kat River and the Brak River have been widened to ease traffic flow and allow for safer pedestrian access. Work began on the Kat River bridge in November 2020 and was completed in July 2022, adding 2 m to each side. The smaller and lower Brak River bridge was widened by 3 m on either side between February and September 2022. The final aspects of the work to Campbell Street, such as the streetlights and sidewalks, were expected to be completed by October 2022, with only road marking and signage outstanding.

Safe, efficient road

To improve the R63 route between Fort Beaufort and Alice, the road design has included extensive vertical and horizontal alignment. This is to meet the Sanral imperative of replacing gravel shoulders, sharp curves and steep slopes with wider paved shoulders, flatter geometry, gentler curves and longer sight distance. There will also be climbing lanes for trucks, to allow safer passing and freer flow of traffic. A community development programme running alongside the road contract will ensure that the new intersections better serve the nearby communities.

“The existing road was only about 6.3 m –which we are widening to 13.4 m,” says De Lacy. “We are putting formal intersections in place and widening the road considerably at these points; some intersections will also be moved to improve sight distance.”

He explains that – from a build programme perspective – the 12 box culverts were the most important elements of the job. In the context of the road realignment, there were fills of 12-15 m with a requirement for a five-month settlement period after fill construction.

“The programme therefore had to be ‘front-loaded’ with these culverts, to ensure there was sufficient time for the fill to settle,” he says. “This allowed all 12 to be completed by November 2021 – by getting an early start and having the necessary aggregate and cement in place to allow for approval of the concrete mix design during the mobilisation stage.”

Building bridges

Realigning the new road has required the building of a completely new bridge over the Mxelo River. This 65 m long five-span structure will stand 8 m above the riverbed, taking the place of the old bridge to be demolished. Two other road-over-rail bridges are also part of the project. The three-span Kwatinidubu rail bridge is 48 m long, while the Kwezana bridge is 52 m long.

“All three structures were designed with monolithic decks, so there are no joints in the bridges,” he says. “This required a 32-hour continuous concrete pour for the Mxelo River bridge, while the pours for the two rail bridge decks were around 24 hours each.”

He emphasises how the extensive vertical alignment changes led to considerable challenges with ground hardness. This required the blasting of around 480 000 m3 of hard material to achieve the necessary design levels.

“It is of course necessary to continue to accommodate traffic on the route while we build the new road, so there needs to be a link-up between old and new roads despite the vertical realignments,” he explains. “This meant that in some areas the temporary road would be too narrow for traffic.”

This was solved by temporarily widening the permanent works to accommodate two-way traffic, resulting in much less disruption to the local community. Blasting was also not permitted near completed roadworks, as the blast could cause an uplift effect on existing layers. The solution here was to extend the bypasses, which has led to the construction of 10.4 km of full-width bypass and 3 km of half-width bypass.

The project’s completion is scheduled for October 2023.

www.afrisam.co.za

By August 2022, over 70 targeted enterprises have been involved and this number is expected to increase to around 90 by the project’s close

From a build programme perspective, the 12 box culverts were the most important elements of the job

A completely new 65 m long five-span bridge is being built over the Mxelo River, with the old bridge to be demolished

INFRASTRUCTURE

AROUND THE CONTINENT

MALAWI

Shire River flood management

The implementation of locally relevant solutions and a national guideline for community-based flood risk management (FRM), aimed at communities and NGOs in the Lower Shire Valley in Malawi, is one of the first of its kind to be developed globally. Leading consulting engineering and infrastructure advisory firm Zutari undertook the project in association with BRLi of France and a local Malawi-based engineering firm.

Prior to the Shire River flood risk management project, no guidelines for FRM planning, design and implementation existed at district, traditional authority or group village head level in Malawi. The project aimed to address this by developing approaches for FRM planning, costing appropriate approaches to address flooding, implementing these in selected villages and capturing these experiences in national guidelines for the Malawian Department of Disaster Management Affairs and the Department of Irrigation and Water Development.

Through intensive and sustained community and stakeholder consultations in the valley, the project identified the communities regularly affected by floods (230 000 people), conceptualised and prioritised interventions for the worst-affected communities (187 000 people), and used hydrodynamic modelling to design 34 large-scale civil works and 41 labour-intensive community-based interventions that will reduce the flood risk of 86 000 and 10 000 people respectively.

Zutari also oversaw the construction of 10 interventions (protection for 45 000 people) and implemented an appropriate flood warning system across the valley operated by the communities themselves.

The designs maximised the use of local labour and materials, are low maintenance in character and, where constructed, have already provided protection during two tropical cyclones. Once the national guidelines were completed, training commenced across the valley. This focused on building a basic understanding of floods, FRM and planning for floods at a community level. The training was undertaken through innovative means, including theatre and advertisements on local radio stations.

KENYA

Self-reading meters to empower end-users

Kenya Power aims to increase its post-paid customers by using selfreading meters.

Last year, the company introduced the self-reading service that is available on the USSD code *977#, where postpaid customers can register to read their meters at the end of their billing cycle and submit the readings for accurate billing.

“Self-reading of meters will empower our postpaid customers to proactively engage with us on all matters that relate to billing for their electricity consumption. It is targeted to enhance satisfaction among our customers through accurate and timely billing, which will eliminate bill

estimations and therefore reduce customer complaints arising from the same,” said Geoffrey Waswa Muli, acting MD, KenPower.

Currently, 2.1 million customers are on postpaid billing while 6.8 million customers are on prepaid (tokens). Apart from selfreading, the USSD code also enables prepaid customers to retrieve the last three purchased tokens, which is helpful especially when customers want to reference their electricity consumption trends.

Customers can also use the platform to report power outages for quick resolution, confirm the authenticity of persons presenting themselves as Kenya Power staff,

as well as track the progress of their connectivity application.

During the last financial year, the monthly average of customer transactions on the *977# platform stood at 1.6 million. The company is targeting to increase these transactions to an average of 2 million by the end of its financial year.

SENEGAL

€28 million towards road improvements

These funds will support the construction of 28 km of urban roads in asphalt, paving stones and concrete that will link six municipalities – Yeumbel Nord (Dakar suburbs), Keur Massar and Guédiawaye (Dakar region), Thiès (west), Kaolack (centre-west), and Saint-Louis (north-west).

This financing will also be used for drainage, public lighting and the construction or repair of cabins that can be used as restaurants and sheds. An empowerment centre will also be set up to advance woman and youth employment. Under the initiative, local authorities will receive training in geographic information systems, database management, planning, investment programming and procurement.

The project forms part of the Senegal Cities Modernisation Programme that contributes towards boosting decentralisation and promoting economic and social development.

GHANA

Recovering waste to reduce methane emissions

The Accra Metropolitan Assembly (AMA) and the C40 Cities Climate Leadership Group, a global network of mayors committed to fighting climate change, are launching the Solid Waste Source Separation and Community Composting Mission programme in Accra, Ghana. The initiative will reduce methane emissions that are partly responsible for global warming.

In Accra, waste generates an average of 44% of methane emissions, 30% of which is responsible for global warming.

The C40 Climate Finance Facility is cofunding the wasteto-energy project with the UK’s Foreign, Commonwealth and Development Office, and the French Development Agency. As part of the project, a system for sorting waste at source will be put in place to facilitate the collection work in the three communities in Accra. The biodegradable material will be processed into fertiliser in a new plant. The plastic can be sold to private operators who will add raw material to make equipment such as chairs, buckets and bowls.

NAMIBIA

Increased length of dry season

Observed changes in temperature extremes, the length of the dry season and rainfall intensity indicate greater climate variability and that the climate in Namibia is tending to become drier.

According to Namibia’s Minister of Environment and Tourism, Pohamba Shifeta, abundant rainfall and fertile land in the Zambezi Region, with its enormous agricultural potential, far surpass other regions in the country.

“Wildlife, rivers, floodplains and forests undoubtedly position the region to contribute significantly to the national economy. Livelihoods entirely depend on forestry-related activities and the use of biodiversity products to support their daily

subsistence. All these natural resource-based livelihoods are vulnerable to climate change to some extent. Apart from temperature changes, rainfall changes have been noticed in the Zambezi Region as well as an increased length of the dry season, a decrease in the number of consecutive wet days and flooding in one season, presenting a special case and phenomena of this region.”

Nearly 70% of Namibia’s population is directly dependent on subsistence agriculture and livestock farming, adding that climate change presents a serious challenge to community livelihoods.

An integrated climate change adaptation project within the agro-ecological landscape of the Sikanjabuka Community Forest aims

to increase the adaptive capacity and improve livelihoods of the community distressed by the negative impacts of climate change.

The project is focused on enhancing crop production and productivity for food security and forest harvesting substitution through the adoption of climateresilient smart farming technologies to support local livelihoods.

It is funded by the Environmental Investment Fund and implemented by the Sikanjabuka Community Forest. To date, a functional greenhouse system has been successfully established with a 10 000 litre water tank installed on-site. In addition, the project has procured one tractor and implemented it for sustainable rangeland management and procured beehives for honey production.

In expert hands, toll roads provide sustainable value

Setting a high standard for world-class toll road operations, Bakwena Platinum Corridor Concessionaire manages the N1 from Pretoria up to Bela Bela (90 km) and the N4 from Doornpoort to the Botswana border (295 km). IMIESA speaks to Danie Verwey (DV), Chief Technical Officer, about strategic planning, construction and maintenance interventions.

What are Bakwena’s key responsibilities as the concessionaire?

DV The concession contract between the South African National Roads Agency (Sanral) and Bakwena came into effect in 2001 and ends in 2031. This is essentially a performance-based agreement that requires Bakwena to complete periodic and routine maintenance, plus specific upgrading works.

As head of the Technical Department, I’m responsible for the management of the engineering infrastructure.

From an overarching perspective, all capital works have been well defined within the initial scope of works as well as over the 30-year concession period. Over the remaining decade of the agreement, that amounts to around R5 billion.

In support of this objective, we run an annual pavement assessment programme, supplemented by a detailed traffic assessment of the entire road. Significantly, all funds for construction works are

self-funded internally via the revenues Bakwena generates as a toll road business.

Bakwena has appointed a long-term operator (acting as a subcontractor) to deal with routine maintenance activities. The latter include grass cutting, accidentrelated damage to infrastructure, cleaning of stormwater systems, replacement of road studs, upkeeping of fences, chemical spraying, street light maintenance, alien vegetation management, and debris and litter management. The total cost for these activities per annum is around R55.6 million or R145 000 per km (not lane kilometres).

For the upgrading component, our forecasted capital expenditure for 2023 is R440 million, entailing major construction works.

What are some of the key projects completed to date?

We have recently completed the construction of the second carriageway between Pretoria and Brits. This section

is some 28 km long and consists of a 10.9 m wide carriageway, two new bridge structures, plus the extension of five existing bridges and seven major culverts. The project was completed at a total cost of R563.4 million (excluding VAT). If you break it down even further, the cost per kilometre was R16.2 million (excluding VAT and the cost for the larger bridge and culvert structures).

Which routes are currently undergoing upgrades?

Two key ones entail major works on the N1 between Pienaarsrivier and Bela Bela Interchange, and the N4 (Section 9) between Ga-Rankuwa and Kameeldrift Interchange, with contract durations of 12 and 18 months, respectively.

The scope of works on the N4 project –scheduled for completion in June 2023 –entails the rehabilitation of both carriageways of the N4-9 (km 0.0 to km 20.8), and includes the rehabilitation of the R80, Kameeldrift, Rosslyn and K99 interchanges.

Danie Verwey, Chief Technical Officer, Bakwena

On the N4-9 section – originally built around 2001 – the sub-base and base of the slow lane have failed and need to be rehabilitated to a depth of 510 mm and then resurfaced with a 60 mm AC modified binder. In turn, the fast lane will receive crack sealing and patching. The fast lane and shoulder will also receive a fog spray upon completion.

The construction cost is around R187.97 million (excluding VAT, CPA and contingencies).

Works on the N1 between Pienaarsrivier and Bela Bela Interchange (km 13.4 to km 42.6) are similarly extensive, entailing the rehabilitation of both carriageways. This will include crack sealing, milling of the slow lanes to various depths and widths, replacement with a bitumen treated base, and a 40 mm asphalt overlay across both carriageway widths with rolled-in chips on both lanes and the fast shoulder.

Scheduled for completion in July 2023, the construction cost here is R174.4 million (excluding VAT, CPA and contingencies).

Both projects serve as prime examples of how Bakwena invests in its assets to deliver the optimum return on investment for its client, while providing road users with the best possible driving experience.

How is Bakwena’s upgrade and maintenance strategy determined?

Since our hand-back requirements in terms of the remaining pavement life are very onerous, we monitor pavement performance very closely.

Our comprehensive pavement rehabilitation strategy is underpinned by an assessment of all performance indicators – i.e. roughness, rutting, visuals and deflections. In turn, bridges and larger structures are inspected over a fiveyear cycle and maintained on an annual basis at a cost of between R6 million to R8 million.

The structures on the N1 are almost 50 years old; here, we focus on repairing spalled concrete, repairing accident damage and applying protective epoxy coatings. We have partnered with Sanral on their Bridge Management System and data is centralised on their Struman database.

Both our upgrade and maintenance strategies are influenced by Bakwena’s comprehensive traffic analysis studies. Forecasting traffic volumes and assessing peak hour flows in the

current volatile economic climate is difficult, but you need to run these models to be able to predict the level of service problems.

Has it worked?

Bakwena has reaped the benefits from proactively maintaining its network. Larger rehabilitation interventions have been postponed from typical 8-year intervals to 10-year intervals, and we have extended the life of our surface seals by crack sealing and employing rejuvenator sprays.

Modern bitumen binders have brought a new dimension to asphalt characteristics. This has been a learning curve from a design perspective over the last decade, but certainly it has provided positive benefits in terms of rut resistance and for pavements exposed to higher traffic loadings (larger than 3 million E80s).

What determines the success or failure of a road asset management system?

The basic principle is to know your infrastructure and spend time with it so that you understand the deterioration cycle. Primarily, though, it’s essential to update your pavement management system annually and know the impact of your traffic loading. We monitor overloading every month via the weighbridges at our traffic control centres on the N1 and N4.

That helps to keep overloading under control, reducing wear and tear.

The lifespan of your road furniture also has to be factored into the overall financial model in terms of routine replacement.

How does Bakwena maximise road safety on its routes?

We have adopted safety audits that are aligned with the South African Road Safety Audit Manual (May 2012). By doing so, we have significantly improved road safety by implementing the recommendations from these assessments.

The safety audits focus on the possible impact of bridge structures, culverts, underpasses and trees relative to the position of the road. We then apply the appropriate remedial measures, which are usually in the form of crash barrier protection.

For new projects, it is vital to adopt these safety principles as part and parcel of the upfront design process.

How does Bakwena compare to best-in-class toll concessionaires?

We are industry leaders in Africa – from both a maintenance and toll operation perspective – and champions of the public-private partnership (PPP) model.

We’ve demonstrated that PPPs can work successfully to deliver value for both parties. In our case, it’s a road network, but PPPs work equally well in other areas like renewable energy (wind and solar), as well as water and wastewater treatment works. They also provide an off-balance-sheet solution for public clients when applied as a build, own, operate project.

South Africa faces a huge challenge to maintain and replace infrastructure, compounded by serious technical skills shortages. Here, PPPs can make a significant contribution by addressing infrastructure backlogs and improving service delivery through outsourced operations and maintenance contracts. Since PPPs are based on bankable business models, projects tend to be executed on time and within budget, and to the highest quality.

Another important point is that private entities are not subject to public sector procurement processes. This means that the need to adhere to a ‘lowest bid wins’ policy – often a contributing factor in subsequent project defects and cost overruns – is not a requirement.

In my view, PPPs must become a preferred mechanism for the provision of engineering infrastructure in South Africa.

And in closing?

The industry is faced with various challenges – especially the uphill battle to maintain infrastructure, exacerbated by bureaucratic red tape. However, our ability to handle these challenges is also a measure of our strength and commitment to make a difference.

It’s not difficult to make the right decisions provided we focus on what is important for South Africa from a sustainable infrastructure perspective. In this respect, well-designed and -maintained toll roads make socioeconomic sense.

Redefining Road Safety Engineering in South Africa

We all know someone who has either lost their life or suffered a life-changing injury due to a road traffic accident. And yet when we step back and think about it, we realise that every accident is indeed preventable, writes Verushka Balaram, Head:

Road Safety and Design Investigations at ARRB Systems, who expands on engineered solutions.

The simple truth is that our road transport system’s level of safety is inadequate and more must be done to tackle this real pandemic. If we consider the problem globally, around 1.3 million lives are lost due to road traffic accidents each year. The majority of these fatalities occur in low- to middle-income countries.

According to the World Health Organization, road traffic injuries remain the leading cause of death among children and young adults aged 5-29 years. In South Africa, we needlessly lose over 14 000 people annually. The holiday periods in December and Easter are typically when crash rates are at their peak, and media coverage of horrific fatal crashes is a daily occurrence.

So, who, or what, is to blame? And how do we tackle this pandemic?

The Safe System

Road safety is ultimately a shared responsibility. The Safe System

approach, which was first adopted by Sweden and the Netherlands, recognises that road transport is a complex system and places safety at its core. It recognises that humans, vehicles and the road infrastructure must interact in a way that ensures a high level of safety. We are human, and we will make mistakes, but we should not lose our lives for it! The Safe System thus requires all stakeholders to act responsibly to realise a safer roads environment.

From an engineering standpoint, the Safe System must:

• incorporate road designs that anticipate and accommodate human errors, and limit crash dynamics to levels that are within human tolerance to prevent death or serious injury

• pursue a commitment of proactive and continuous improvement of road networks

so that the entire system is made safe, rather than just locations or situations where crashes last occurred

• motivate those who design and maintain the roads, and administer safety programmes, to share responsibility for safety with road users, so that when a collision occurs, remedies are sought throughout the system, rather than solely blaming the driver or other road users

• adhere to the underlying premise that the transport system should produce zero deaths or serious injuries and that safety should not be compromised for the sake of other factors such as cost or the desire for faster transport times.

Reactive vs proactive approach

Safety plans that are based on crash data to identify areas where clusters of serious accidents have previously occurred, or ‘black spots’, are reactive and insufficient to support a Safe System approach. There is a high reliance on good-quality data, which is not always available. As such, black spots

iRAP assessments require a digital survey of the road with an approved inspection system, such as the ARRB Systems Hawkeye 2000 Network Survey Vehicle.

This is employed to capture georeferenced images for safety assessments

Verushka Balaram, Head: Road Safety and Design Investigations at ARRB Systems, is iRAP accredited and an International Road Federation Global Road Safety Audit Team Leader

Deep drainage

sidewalk present

No curve delineation

may constitute just a fraction of the entire road network; other unsafe areas, which only become evident after serious crashes, are not identified until it is too late.

Conversely, safety plans developed by focusing on fundamental flaws in designs and those inherent in existing roads are proactive and can identify where serious road accidents are likely to occur. Road Safety Audits (RSAs) and the International Road Assessment Programme (iRAP) both offer proactive approaches for road infrastructure safety management.

RSAs are particularly effective during the design and construction stages of a road project, where the focus can be on future crash prevention by mitigating potential hazards before the road is opened to the public. An independent, qualified team examines road user and traffic interactions to determine the crash potential and severity, which are combined to determine the level of risk and associated remedy. RSAs are performed at any of the following stages:

Stage 1: Feasibility/Preliminary Design

Stage 2: Draft Design

Stage 3: Detailed Design

Stage 4: Construction Work Zone

Stage 5: Pre-opening

Stage 6: Post-construction: Existing Road (Road Safety Appraisal).

It is encouraging to note SANRAL includes RSAs as a precondition to all of their road projects, at both the design and construction stages. Not only is this beneficial from a safety standpoint, but it also promotes SMME and QSE development.

iRAP methodology

The iRAP methodology is typically performed at the network level and is an evidencebased approach to identify and address hazardous road locations, providing an in-depth understanding of the level of safety evident on each road.

iRAP assessments require a digital survey of the road with an approved inspection system,

such as the ARRB Systems Hawkeye 2000 Network Survey Vehicle (NSV). However, if the roads agency is already collecting condition data for its RAMS with the NSV, then there is no need for a separate safety survey, as the same data can be used, making the process economical.

The surveyed data is used for the assessment of more than 52 roadside attributes and is combined with supporting information such as speed data, vehicle and pedestrian flow data, and traffic volumes. This produces ‘Star Ratings’, which is the global benchmark used to estimate risk that a person – whether a vehicle occupant, motorcyclist, cyclist or pedestrian –will be killed or seriously injured. 1-Star roads and designs have the highest infrastructurerelated risk, while 5-Star roads have the lowest.

iRAP incorporates the use of a free online portal (ViDA), where users can upload road inspection data, produce detailed road condition reports, Star Ratings and Safer Roads Investment Plans. iRAP also conforms to the UN’s Global Road Safety Performance Targets 3 and 4, which state that by 2030, all new roads, and more than 75% of travel on existing roads, must achieve at least a 3-Star rating.

In South Africa, ARRB Systems’ iRAPaccredited team has undertaken safety assessments on more than 20 000 km of provincial and municipal roads. These agencies are seeing the benefit of iRAP network assessments to develop a priority list of safety countermeasures to both motivate for funding and use as an implementation strategy. Additionally, iRAP assessments can monitor

road safety performance so that both National Treasury and the roads agency can assess the benefits of their investments over time.

Pros and cons

Both RSAs and iRAP have their advantages and disadvantages. For example, RSAs can be done at night and there isn’t a limit to the level of detail that can be considered. However, the level of subjectivity can lead to inconsistent outcomes and long road sections can prove challenging for the assessment team.

The main benefit of the iRAP methodology is that there is no need to undertake an entirely separate data gathering exercise. Imagery and much of the associated data is already collected as part of the roads agency’s pavement management system, so there is no duplicated cost to re-survey the road network.

The iRAP assessment provides the road network manager with a holistic overview of the network’s level of safety and identifies hazardous locations, often not known to the roads agency. However, the list of assessed attributes, though comprehensive, is fixed, and the quality of the results depends on the quality of the input data, making the process reliant on strict protocols.

Whichever approach is used, the critical aspect is that action is taken, and loss of life is prevented! Safety assessments are meaningless without implementation. Roads agencies must lead and facilitate road safety strategies as a priority. Leadership is thus intrinsic in implementing correct reforms to accommodate advances in technology and best practices.

In South Africa, ARRB Systems’ iRAP-accredited team has undertaken safety assessments on more than 20 000 km of provincial and municipal roads

rating for vehicle

Assessing the impact of road provision on economic performance

Judging the state of an economy typically factors in five key macroeconomic criteria1

These comprise economic growth (including economic development), full employment, price stability, balance of payments stability, and equitable distribution of income, all of which in turn

have a bearing on the planning, investment and construction of transportation systems.

Positive economic growth occurs only if total real income increases at a faster rate than the population. Only then will average living standards per person increase.

A holistic developmental viewpoint of economic growth must therefore take distributive criteria into consideration –e.g. apart from per capita growth of GDP, an increasing proportion of the population should ideally become materially better off. Additionally, more essential governmental service delivery points (like health services and schools) should be located closer to those groups in the community who lack personal mobility.

Investment in road infrastructure will only underpin economic growth and development if the prerequisite factors of production are available – e.g. sufficient land, access to raw materials, qualified labour, functional utilities (like water and electricity supply) and entrepreneurs who are able and willing to invest in the service area(s) of such roads.

Full employment

The second macroeconomic objective is full employment. However, it is unlikely that this can ever be achieved. It is therefore more realistic to view the goal of full employment as the objective of achieving maximum attainable employment or minimising unemployment.

Road construction, incorporating community participation goals, provides excellent opportunities for temporary and permanent employment, plus the transportation framework implemented should have local socio-economic benefits.

The estimate of the number and type of human resources to be employed in the construction of a road project used in the economic impact analysis (ECIA) must be the estimate of a professional quantity surveyor approved by the road authority. If such an estimate has not been finalised at the time that the ECIA is performed, the assistance of a road quantity surveyor or a road construction project manager or a road construction human resources specialist should be sought.

When integrated as part of an effective transportation system, roads play a key role in stimulating microand macroeconomic performance. Determining their degree of effectiveness, however, must also consider the social benefits, particularly in terms of addressing poverty, unemployment and inequality.

By Professor WJ (Wessel) Pienaar*

(Credit: Pixabay)

Price stability

The third macroeconomic objective is price stability with the aim of keeping inflation as low as possible. Within the context of construction, price stability is supported by a saving of economic resources through a lowering of the cost of (road) transport. A saving on transport costs resulting from a new or improved road contributes to more efficient national resource allocation.

Transport demand

A characteristic of transport is that it is not demanded in its own right; it is a means to an end. Therefore, the basis of any analysis of the demand for transport is the fact that this demand is a derived function of other activities.

A road project is regarded as economically justified when the present worth of the reduction in recurring costs during its service life exceeds the present worth of the once-off investment cost of implementing the road. The benefits are determined as the difference in recurring costs without and with the road improvement.

The measure of absolute viability of a project is shown by the size of its net present value (NPV), and the measure of relative viability is shown by its benefit-cost (B/C) ratio or its internal rate of return (IRR) – the former as a ratio and the latter as a percentage.

Balance of payments stability

The fourth macroeconomic objective is balance of payments stability. The balance of payments is a record of a country’s international transactions in a given period, usually one year.

Modern economies are highly interdependent, and the successful ones are those that compete effectively in international markets. In a rapidly integrating and globalising world market, therefore, efficient and effective transport and other logistic support structures relating to international goods transactions are of particular importance2.

In this respect, import expenditure represents approximately 7.4% of the total construction expenditure of rural bituminised road projects in South Africa3.

Considering that a road is a capital good, often involving the importation of technically advanced capital equipment and the creation of specialised industrial capacity, an import propensity of 7.4% is very low.

Equitable distribution of income

The fifth macroeconomic objective is equitable distribution of income. The National Development Commission in South Africa acknowledged that welfare in the country is distributed alarmingly unequally and explains its concern in this regard with reference to the Gini coefficient4. This coefficient provides an indication of income inequality, which ranges in value from 1 in the case of total inequality to 0 in the case of total equality. The Gini coefficient is equal to the ratio of the area between the diagonal and the Lorenz curve divided by the total area of the triangle in which the curve lies.

The Lorenz curve is constructed by plotting the numbers of income recipients, starting with the poorest on the horizontal axis in cumulative percentages and with cumulative personal income percentages on the vertical axis.

The Gini coefficient internationally usually ranges between approximately 0.3 (highly equal) and approximately 0.7 (highly unequal)1. In 2011, South Africa’s Gini coefficient was 0.65. The fact that South Africa is frequently indicated as having the highest, or almost the highest, Gini coefficient is evidence of the highly inegalitarian income distribution that characterises the South African economy1

Roads and transit modes that close the inequality gap

The provision and use of new and improved roads (especially access roads) and other public road transport facilities (like passenger transport terminals and transfer facilities) can lead to a more equitable distribution of social welfare and income (economic welfare). The users of public transport facilities and services, for example, are mostly transit-captive travellers, as they often do not have the ability to pay for travel on alternative modes of transport, and they are, by implication, the needier group in a community.

Because the appreciation of the marginal utility of income among lower-income groups is considerably higher than among more prosperous individuals, the net economic benefits that a transport project has for them should be weighted accordingly in a social cost benefit analysis (SCBA). From a distributive efficiency (equity) viewpoint, this will ensure that in selecting a project, the one that can make the greatest net contribution to welfare distribution is chosen for implementation.

The method that is used for incorporating social equity in an SCBA is based on

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the application of weights to the benefits that are received by the low-income group. The economic impact stemming from the inclusion of welfare distribution weights in an SCBA are twofold.

First, from a transport economic viewpoint, the inclusion of equity in the evaluation process is geared to creating equal accessibility and increased mobility for lowerincome groups in terms of marginal utility.

Second, and from a general economic point of view, striving for greater equity is geared towards allotting potential economic activity and its returns to lower-income communities.

Welfare distribution weights can either be based on income or on consumer spending.

Traditionally, the weights have been based on per capita income. However, there are two considerations that argue that the weights should be based on per capita consumer spending. The first point is a matter of principle and the second a matter of practice5:

First point: the relationship between income and utility attainment is not clear, while per capita consumption expenditure provides a relatively good indication of this relationship.

Individuals with the least income must expend their disposable income mainly on life necessities and basic needs satisfaction, while individuals in the middle-income group also have an opportunity for precautionary savings, for example, contributions towards pension, insurance and medical funds.

Second point: it will require a considerable amount of calculation and bold assumptions

to deduce gains in personal utility from total income, as all transfer payments to and from individuals are not reported in total income statistics.

The importance of location

The measure to which a new road can potentially contribute to a redistribution of welfare among regional populations is a function of regional accessibility.

It is a requirement that an ECIA must address and report the potential of each of the analysed road projects to contribute to a redistribution of per capita income as follows:

• Where an entire road project is located within a single municipal area: Indicate the annual per capita household (final or private) expenditure within the municipal area as a ratio of the annual per capita expenditure within the province in which it is located. The report also needs to state the municipal population.

• Where a road stretches through more than one municipal area within a single province: Indicate the annual per capita household expenditure within each of the municipal areas as a ratio of the annual per capita expenditure within the province in which the municipalities are located, as well as the number of intersections and interchanges on the road that provide access to and egress from the province. The population in each municipality must also be stated.

• Where a road stretches through more than one provincial area: Indicate the annual per capita household expenditure within each of the municipal areas in each province as a ratio of the annual per capita household expenditure within the province in which it is located, and the annual per capita household expenditure within each province as a ratio of the annual per capita household expenditure within the country, as well as the number of intersections and interchanges on the road that provide access to and egress from the relevant municipal area and the relevant province. The population of each municipality and each province must also be recorded.

Conclusions

Roads exist for the transit of goods and people and, when well planned, have farreaching benefits for economies. At a higher level, transportation masterplans can also make a real difference in closing South Africa’s inequality gap by connecting communities, enabling employment, and facilitating macro- and microeconomic developments.

REFERENCES

1 Mohr, P. 2019. Economic indicators, Sixth edition. Pretoria: Van Schaik Publishers

2 Pienaar, W.J. & Vogt, J.J. 2016. Business Logistics Management, Fifth edition. Cape Town: Oxford University Press

3 Pienaar, W.J. 2021. Determination of the cost component in the social cost-benefit analysis of road projects in South Africa. South African Journal of Industrial Engineering. Vol 32(1), 14-23

4 National Planning Commission (NPC). 2011. National Development Plan: Vision for 2030 www.npconline.co.za/.../NPC%20 National%20Development%20 Plan%2 [18/08/2022]

5 Committee of Transport Officials (COTO). 2022. Economic impact analysis of road projects, Volume 2, Committee Draft CD2. Pretoria: COTO

*Department of Industrial Engineering, Stellenbosch University

AECOM racks up experience from Ghana to Lesotho and beyond T

his ranges from the Tema Port Expansion Project in Ghana to the Polihali Western Access Road (PWAR) Project as part of Phase II of the Lesotho Highlands Water Project, upgrading Section 2 of Moloto Road, being lead consultant for Phase 1 of the Gautrain Rapid Rail Link Project, and its involvement with a major transport project in Saudi Arabia.

A feather in the cap for the team was the New Ashton Arch Bridge, South Africa’s first transversely launched concrete tied-arch bridge, which was awarded Best Infrastructure Project greater than R100 million at the 2022 Fulton Awards, held every two years

by Cement & Concrete SA. The project also received a commendation for Innovation & Invention in Concrete. The judges praised the New Ashton Arch for its “unique bridge engineering technique”.

“The biggest part of our transportation team sits in our Highways & Bridges teams. We probably have one of the largest bridge teams in the country,” says Chris Britz, director: Transport, Africa at AECOM. Current work includes the 580 m long, cable-stayed Msikaba Bridge in the Eastern Cape, part of Sanral’s N2 Wild Coast project.

Britz explains that Transport falls under the Civil Infrastructure business line of the Africa business, together with Water, Environmental and Geotechnical. The business line is divided into market sectors – namely Highways & Bridges, Rail, Infrastructure Design, and Ports & Marine – dealing mainly with smaller

municipal-type developments and associated services such as roads, water, drainage and sewerage.

Construction management and construction supervision

Another major focus is construction management and construction supervision (CMCS), which allows AECOM to offer full services for both civil and transportation projects. This involves six main stages, from concept to design, documentation, procurement, supervision and closeout.

“That is a bit different from other markets where design and documentation is often one contract, with a separate contract for the supervision, contract management and closeout. Most of our larger and more significant projects run across all six stages and therefore it is essential that we have a strong CMCS team in-house,” explains Britz.

AECOM plans, engineers and oversees the construction of some of the largest port and

The transportation business line for globally trusted infrastructure firm AECOM has both extensive experience and an impressive track record.

Chris Britz, director: Transport, Africa at AECOM

AECOM was involved in upgrading Section 2 of Moloto Road

TRANSPORTATION

marine facilities worldwide, including Tema Port in Ghana. The firm has been involved here for the last six years, providing a multidisciplinary service for the port’s vital expansion. AECOM expects to complete a separate LNG terminal project before the end of the year.

These projects follow on from previous work carried out by the marine team in South Africa on the Dig-Out Port at the old Durban International Airport site. The local team has also received support from the AECOM Global Aviation business line for airport projects done on behalf of Airports Company South Africa (ACSA), such as the King Shaka and Cape Town international airports.

The latter is a good example of AECOM’s multidisciplinary approach to projects. “Our ACSA work usually involves our Buildings team on the terminal side and our Bridges & Highways team on the aprons and runways, as the approach to pavements is largely similar,” highlights Britz.

“Our Infrastructure team supports other parts of the business internally. Our Highways & Bridges team also has a good industrial

capability and resumé. Here, the Infrastructure team assists with the design of the bulk earthworks and all the services typically associated with an industrial site,” he outlines.

An example of AECOM’s involvement here is its work for Toyota South Africa at its Prospecton manufacturing facility in Durban.

The recent flooding in KwaZulu-Natal caused major damage to the plant, with AECOM working on a feasibility study to elevate the entire site as part of a larger climate-resiliency strategy for the automotive manufacturer.

Another major client for the Transport team is the Western Cape Government. Past project examples include the New Ashton Arch Bridge forming part of the larger Cogmanskloof pass upgrade. AECOM is currently carrying out various other road upgrades, reseal and gravelto-surface road projects in the province.

Britz notes that bidding for highway projects is highly competitive due to the general dearth of infrastructure tenders in the market.

Digital transformation strategy

Given the constrained local market, AECOM’s digital transformation strategy has seen it branch out into Australia and New Zealand to tap into major infrastructure projects being undertaken currently in those territories.

“Although Australia uses different design packages that are unique to their market, their business culture and work ethic are highly compatible with South Africa,” points out Britz.

With digital advancements and virtual working, the South African team is expanding its current involvement in global projects, supporting teams in the Middle East, UK and USA.

In addition to its digital transformation drive, another key strategy for AECOM is Sustainable Legacies, which promotes environmental, social and governance (ESG) goals in all its projects. A good example is the PWAR Project in Lesotho, where the road provides not only access for the equipment necessary to build the dam, but also linkages and mobility for local communities.

“The road will ultimately link many roads and settlements in Lesotho to the outside world,” Britz concludes.

South view of the New Ashton Arch Bridge

AECOM overseeing design and construction supervision of the Polihali Western Access Road

AECOM was involved in a fuel works project at King Shaka International Airport in Durban

By Leon Prinsloo

Reducing non-revenue energy within municipalities

High losses place a burden on municipalities as the revenue generated from electricity sales may become insufficient to service the cost of purchasing electricity from Eskom.

To just increase the tariff for electricity sales is not the answer, as there are NERSA compliance requirements, but it would also be unfair towards paying customers to foot the bill for non-paying customers. Municipalities, therefore, need to have comprehensive management plans to address the issues of energy losses.

Energy losses can be described as energy bought from the supplier (Eskom) which is not sold for various reasons, thereby leaving a gap between what has been bought and what is being sold. Losses can further be broken down into technical and nontechnical losses. Technical losses occur naturally in the network. It is basically the dissipation of power in electrical system components such as transmission lines and power transformers.

Commercial losses

Non-technical losses occur when electricity is consumed, but is not accurately recorded, either through legal or illegal consumption.

Typical examples of where non-technical losses may occur are:

• Unknown or unmetered connection points: This typically occurs where a meter is installed, but the information of the meter (whether prepaid or conventional)

has not been recorded in the municipality’s financial system. A connection point that is not correctly registered in the system leads to a user that legally consumes energy but is not billed as the user or the meter is not in the database.

• Faulty meters: For as long as the faulty meter remains at the connection point, the user is consuming energy legally but does not get billed due to the meter not registering consumption.

• Meter tampering: Meter tampering happens when a user illegally tampers with a meter by either bypassing the meter completely or making the meter ‘slow’ so that only a portion of the consumption is recorded.

• Ghost vending: This term is generally used where syndicates are selling prepaid electricity to a consumer, but the consumption does not register in the municipality’s official system.

Non-technical losses, therefore, happen on the commercial side of a municipality’s business and are also often termed commercial losses. If left unchecked, nontechnical losses will quickly escalate out of control.

Vuthela iLembe LED Support Programme

Within the KwaZulu-Natal province,

proactive measures to address these issues are being driven through the Vuthela iLembe LED Support Programme, which appointed Zutari as the consultant to assist the local municipalities of KwaDukuza and Mandeni to reduce their energy losses and at the same time improve revenue from electricity services.

During the analysis process, it was discovered that Mandeni is on an Eskom tariff that leads to them paying more per gigawatt hour (GWh) of electricity than the metros. Mandeni has been assisted with a draft letter to query this tariff with Eskom, with the aim of possibly moving to a tariff structure that is more conducive to the municipality’s needs.

An analysis of the status quo within KwaDukuza has also identified areas for optimisation. Experience has shown that one of the best examples of a quick win is to review the consumption patterns of large power users (LPUs).

A short-term intervention of auditing the consumption patterns of at least 120 LPU customers in KwaDukuza that are on functional automated meter reading may well lead to a conservative estimate of the recovery of R12 million of lost energy at a return on investment of over 600%.

Electricity that is used by consumers and is not paid for results in loss of revenue for the providers, which are in most cases municipalities.

Leon Prinsloo, associate: Asset Management at Zutari

Awards for excellence in consulting engineering

Engineering Technology and Innovation – Renewable Energy Systems Design Excellence

Commendation: Zutari, for the Golomoti Solar PV and Battery Energy Storage project of JCM Solar Corporation Limited.

Business Excellence

Naidu Consulting.

In 2022, we are very proud to be celebrating 50 years of hosting this prestigious event with a focus on consulting engineers and their clients who participate in or initiate projects that promote the advancement of our nation and the people of the continent,” says Chris Campbell, CEO, CESA.

The winners in their respective categories are:

Lifetime Industry Achievement Award

Tim Ter Haar was recognised for his contribution to the development and promotion of the consulting engineering industry with the Lifetime Industry Achievement Award, which was presented to him posthumously.

Visionary Client of the Year

The Western Cape Department of Transport and Public Works, Roads Branch was recognised as the Visionary Client of the Year for fully following the key commitments of their service delivery charter.

Projects with a value between R250 million and R1 billion

Winner: Zutari, for the TASEZ ‘Cluster 2’ Ford Frame project.

Commendation: AECOM, for the rehabilitation of Trunk Road between Ashton and Montagu for the Western Cape Government’s Department of Transport and Public Works, Roads Branch.

Projects with a value between R50 million and R250 million

Winner: Zutari, for the upgrading of 8 Merchant Place for Rand Merchant Bank (RMB).

Commendations:

- Merchelles Collective, for Coca-Cola’s Polokwane Manufacturing Facility Infrastructure upgrade. - Nathoo Mbenyane Engineers, for the upgrading of Dipaleseng Local Municipality’s Balfour Wastewater Treatment Works (Phases 2 and 3).

Projects with a value less than R50 million

Winner: Royal HaskoningDHV, for the Brandwacht Pedestrian Bridge for Mossel Bay Municipality.

Commendation: Naidu Consulting, for the Design and Management of a Labour-intensive Capacity Building Programme for MISA.

Best International Project

Winner: Zutari, for the Golomoti Solar PV and Battery Energy Storage project in Malawi.

Commendation: Bigen Africa, for the Palapye Water Treatment Works Expansion Project in Botswana.

Engineering Technology and Innovation – HVAC Building Systems Design Excellence

Winner: Maninga Engineering for the Commerce, Law, and Management (CLM) building development for Wits University.

Small/Medium Company of the Year Maninga Engineering.

Mentoring Company of the Year Nyeleti Consulting.

Mentor of the Year

Gengan Govender’s commitment in consistently finding ways to assist and mentor his co-workers contributed towards receiving the accolade.

Young Engineer of the Year

Each year, CESA recognises the contribution young engineers make to the profession. In the much-anticipated Young Engineer of the Year category, Saiuree Nayager was named winner while Swesha Machere received a commendation.

A vital contribution to society

In her speech at the awards, Clarissa Rizzo, business unit manager: Professional Risks, Aon, stated, “As a longstanding sponsor of the CESA awards, we have come to experience and appreciate the massive contribution that the engineering industry makes to our economy and society. Through all the many challenges and risks – and they have been complex and many of late – this industry remains a hallmark of a modern, progressive society.”

Hosted by Consulting Engineers South Africa (CESA) in partnership with Aon South Africa, the CESA Aon Engineering Excellence Awards returned as an in-person awards ceremony for the first time since August 2019. The awards celebrate innovation, quality, outstanding workmanship and professionalism.

The issue of planning, ownership and plan approvals

Security of tenue in South Africa is essentially guaranteed by two professions, namely the land surveyor and the conveyancer. Peter Newmarch, president of the South African Geomatics Institute (SAGI), expands on the key role that cadastral surveys play in construction, municipal consent and ownership processes.

By Alastair Currie

As Newmarch points out, there is a major difference between submitting a building plan and planning in general. “In terms of the latter, planning can be defined as a multidisciplinary area of work across all built environment disciplines. Within the public sector, municipalities plan for their future infrastructure needs in line with projected socio-economic trends, examples of which include new roads, water and sewer network upgrades, residential, commercial and industrial zoning,” he explains.

A building or development plan, on the other hand, is an application by a

private owner or developer to change their rights, e.g. by subdividing sections of their existing property. (Public sector entities are not legally obligated to submit a full set of building plans, except for structural matters.) The application is typically submitted to the local municipality and/or applicable organ of state – like a roads department.

“The process of legally effecting this formal change in rights through the various offices of the Surveyor General is reserved work that can only be performed by a land surveyor,” Newmarch continues.

“However, any property owner or registered professional, such as a land surveyor,

Peter Newmarch, president, South African Geomatics Institute (SAGI)

architect, engineer or town planner (even a lawyer), can submit an application, including a layout plan. And that plan must record all existing elements (rights, restrictions and responsibilities), including underground services and heights/contours.”

Layout versus cadastral plan

Things become challenging, however, when the layout plan has not been verified by a land surveyor. While GPS technologies now make it possible for anyone to produce a lifelike map in their application for some form of development right, Newmarch says it is important to emphasise that these are not accurate from a cadastral and mapping perspective.

“All these non-surveyor-produced maps, including self-help GPS position and Google Earth image or other non-rectified imagery, are incorrect and are not connected to the national control and level system of the country – a vital system for the orderly development of society and land administration,” Newmarch explains.

“Accepting these coordinates, heights and images at face value can and does lead to flawed decisions at the expense of a municipality and it’s not uncommon to see a map that shows water flowing uphill! I’ve also seen roads get built with hugely inaccurate quantities because the base mapping was done incorrectly or developments where

Aerial survey and cadastral overlay

water flows on to neighbouring properties or where services do not run in servitudes.”

Planning and survey of all rights

There is a clause in the Geomatics Profession Act (No. 19 of 2013) that covers the planning and survey of all rights (as opposed to simply real rights [property ownership]). An example of a right is the permission granted to a person by an owner to live on their land for a predetermined period.

“Any application in terms of any legislation for any right which has the end objective of leading to a diagram, sectional title or a general plan is reserved for a land surveyor,” Newmarch expands.

Responsibility to protect the public

The land surveyor’s duty is to protect the public, and the cadastral rights system, by ensuring that every prescribed legal step has been followed. In addition to ensuring that the cadastral information is accurate, this includes checking existing title deeds (which supersedes planning schemes) to ensure that rights do not unexpectedly pop out of the system and cost developers and owners time and money. There are also proclamations and a range of other avenues in which rights are recorded.

An example would be an environmental right stated in a title deed that prohibits any new development within, say, 200 m from the top of a specified hill, or an existing land rights claim. Unresolved deceased estates where no will exists is another common issue that can stall a project. From SAGI’s perspective, it should be mandatory for every property owner to have a will.

“The important point to make is that the land surveyor is legally required to obtain consent from all affected parties, which requires extensive investigation and due diligence, and to record all rights and real rights so that the state can make informed decisions on any application.” Newmarch asserts.

Approving the plan

For this reason, it is essential that building plans – and for that matter any other type of plan that needs approval (e.g. land use and development applications) – are only approved by suitably qualified municipal and allied state officials. The framework for every building plan is a cadastral boundary of the property – it forms the setting-out basis of every building.

The land surveyor must confirm that the survey beacons are in place and correct to prevent encroachment on to a neighbouring demarcated property and also to ensure building lines are preserved and SANS standards of position of buildings are adhered to. (Alarmingly, SAGI estimates that some 60-70% of all property beacons are missing – which makes one wonder how buildings can even comply with legislation.)

“Only once all the steps have been verified should building commence according to the approved plan. This ensures that rights are protected. However, it also ensures that municipal property valuations are up to date and the correct rates and taxes are being collected,” says Newmarch.

“Since irregular plan approvals continue to be an issue – and, once approved, are legally challenging to reverse – we could well see a change going forward, where the law makes it a requirement for all approved applications to be channelled through a land surveyor to make sure they are spatially and legally compliant,” adds Newmarch.

“If municipalities are not accurately recording and maintaining building, infrastructure and ownership data, it becomes difficult to plan for future land usage, such as social infrastructure and low-cost housing. Unlocking the value of land development is dependent on precise cadastral information, which is the responsibility of the land surveyor,” Newmarch concludes.

The land surveyor’s duty is to protect the public, and the cadastral rights system, by ensuring that every prescribed legal step has been followed

Solar geyser local content requirements create jobs

Solar water heaters, or solar geysers as they are commonly known, are in great demand as a more energy-efficient alternative to their electrical counterparts. This presents major growth opportunities for South Africa-based manufacturers, with the proviso that 70% of the components must be manufactured and sourced locally according to threshold stipulations by the Department of Trade, Industry and Competition.

In this respect, the South African Bureau of Standards (SABS) was appointed as the local content verification body in terms of the amended regulations to the Preferential Procurement Policy Framework Act (No. 5 of 2000).

“The SABS acknowledges that a number of manufacturers have their products tested and certified as part of a product

SABS_IMIESA-HP_11-2021.pdf 1 2021/11/23 19:47

Local content verification for solar geysers is conducted and calculated in accordance with SANS 1286 ‘Local goods, services and works – measurement and verification of local content’

certification scheme; however, it is the local content verification element that is missing. Currently, there are no local solar water geysers that meet the local content requirements,” explains Jodi Scholtz, lead administrator, SABS.

Local content grading scheme

Manufacturers of components for solar geysers can have their parts locally verified as part of the SABS local content grading scheme. The main components of a solar water geyser are the collector, the heat transfer system and the storage vessel.

A grade from A to J is assigned, based on the criteria being met, where A has 90-100%

local content and J from 1-9%. This is a five-year scheme and gives manufacturers the flexibility to incrementally increase the percentage of local content in products over the period.

“By having components sourced and manufactured locally, industries and economies can flourish. We further encourage suppliers to have their components verified for local content, as it will create a demand for manufacturers to meet the local content requirements,” adds Scholtz.

Other products in the plumbing sector that need to meet local content determinations include ducting and structural pipework, gutters, downpipes and lauders, polyvinyl chloride (PVC) pipes, high-density polyethylene (HDPE) pipes, polypropylene (PP) pipes, glass reinforced plastic (GRP) pipes, valve products and actuators.

SABS has been driving Standardisation, Testing, Certification and Training in building and construction industry, such as: civil and construction for example steel and concrete works, and the building industry for example bricks, paving blocks, roof tiles, cement & concrete products.

SANS 10400 - The application of the National Building Regulations. Development in the building industry is a continuous process. New materials become available, design methods are refined, and innovative building systems. Development of new policies and procedures within building and construction might impact regulatory requirements, these interpretations cannot remain static if they are to accommodate such policy changes and allow for the early use of innovation in construction. The current setup has introduced full test automation of tests that are performed on the test bench in both SANS 60335-2-21 and SANS 151 test standards.

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FIBRE BANDWIDTH EXPLOSION IN SOUTH AFRICA

Equiano (backed by Google) landed at Melkbosstrand in August, while a second cable – 2Africa (backed by Facebook) – is scheduled to go live in Q4 2023.

These cables will help to improve internet capacity in the country while Google and Facebook can facilitate the connectivity of more consumers on to their app or ecosystem to increase profit per subscriber.

“The connectivity that will be unlocked through Equiano will have an immense impact on the information and communications technology sector and the domestic economy overall. The capacity that Equiano offers will make connectivity more accessible and affordable, helping to bridge the digital divide in South Africa. Making connectivity more attainable will also allow small businesses to embrace digital innovation and fully step into the digital economy,” says Serame Taukobong, CEO, Telkom.

Equiano

The Equiano submarine cable system’s scheduled launch date is in the fourth quarter of 2022, and Google is the sole owner of the system. Its supplier is Alcatel Submarine Networks.

Equiano’s landing point in South Africa is Melkbosstrand, near Cape Town, operated by Telkom’s wholesale and networks division, Openserve. Openserve’s cable station facility serves as the South

African landing station and will offer terrestrial services, connecting the cable landing to South African carrierneutral data centres.

This followed the first landing of the cable in St Helena one year ago, before branching out to landings in Togo, Nigeria and Namibia in 2022. Equiano runs from Portugal along the west coast of Africa to South Africa.

The undersea cable, which has a capacity of 144 Tbps, which is 20 times the capacity of the last cable built to serve the region, is the first to incorporate optical switching at the fibre-pair level, as opposed to the traditional approach of wavelengthlevel switching.

The Equiano cable was named after Nigerian-born writer and abolitionist Olaudah Equiano.

Google Cloud

With the improved internet speeds,

Google is launching a cloud service specifically for the African continent and the infrastructure will be hosted in South Africa. Takealot’s e-commerce platform has already been built on Google Cloud.

Along with the cloud region, Google is expanding its network through the Equiano subsea cable and building dedicated cloud sites in Johannesburg, Cape Town, Lagos and Nairobi. In doing so, they are building full-scale cloud capability for Africa.

Google Cloud will help users, developers, businesses and educational institutions across Africa to move more information and tools online. The users will be given the option to store their data in the country of their choice. This will allow companies to comply with local laws prohibiting the storage of data outside of the country.

2Africa

The 2Africa submarine cable will span a length of 45 000 km, almost encircling the continent of Africa entirely. It is the longest subsea cable in the world and is scheduled to launch in South Africa in 2023.

Major investors in the cable system are China Mobile, MTN, Meta Platforms (formerly Facebook), Orange, Saudi Telecom, Telecom Egypt, Vodafone, and the West Indian Ocean Cable Company.

Total trust, infinite growth Secure the future of your business

Public sector must reimagine cybersecurity to enable e-government ideal

By Sinamava Hina-Mvoko - Managing Executive for Public Sector at BCX

The South African government has demonstrated a deep understanding of how important the 4IR and a digital economy can be for our country’s development. But security is the foundation and enabler of the 4IR and digital government, and needs to be addressed first.

Critical infrastructure and government departments are under fire worldwide, as cyberattackers target the most crucial systems for the largest payout. Power grids, ports, water and oil pipelines are being attacked, with IBM’s latest Cost of a Data Breach Report1 saying 28% of breaches in critical infrastructure were ransomware or destructive attacks, with average breach costs topping $5.4 million in cases where organisations did not have zero trust strategies.

In South Africa, a number of government-related entities and departments are among those to have come under attack, with one, high-profile incident disrupting operations for two weeks, causing up to R1 billion in losses.

The public sector must not only maintain operational resilience; it must also protect and secure the personal and sensitive data of its citizens, reduce the risk of fraud and theft of public funds, and enable productivity and cost control as part of its cyber risk mitigation efforts.

But while critical-infrastructure attacks cause dramatic outages that make headlines, the attacks on critical systems within public-sector departments – right down to local municipalities – can be equally damaging and disruptive for those affected. Earlier this month, an attack on a small, local municipality took down its systems, email and landlines for several days.

The public sector must not only maintain operational resilience; it must also protect and secure the personal and sensitive data of its citizens, reduce the risk of fraud and theft of public funds, and enable productivity and cost control as part of its cyber risk mitigation efforts.

As a preferred security supplier to the South African public sector, BCX has worked with many publicsector agencies at local, regional and national level to help them mitigate cyber risk. In our experience, public sector CIOs and CISOs are well aware of the growing cyber risk, and are making every effort to protect their organisations. But they face a number of challenges as they do so.

A key issue is the legacy systems still widely in use in many public-sector agencies. With some systems over 40 years old and no longer supported, these systems are potential entry points that make their entire ecosystems vulnerable. Departments are struggling to integrate those legacy systems, and have limited visibility into them.

Safeguard your evolution

A key issue is the legacy systems still widely in use in many public-sector agencies. With some systems over 40 years old and no longer supported, these systems are potential entry points that make their entire ecosystems vulnerable

Many departments are also challenged in getting the very basics of cybersecurity right: they may have solutions that have not been upgraded to align with the latest acceptable standards, the devices in use might not be secure, and end-users may not be up to date with cybercrime tactics and risks.

Tackling these challenges to mitigate risk requires a holistic approach, typically implemented in phases. As a systems integrator, we are well positioned to implement end-to-end solutions that reduce risk in a comprehensive way.

These systems often also depend on manual processes, which open these departments to the additional risks of fraud and human error.

Security is also challenged by increasingly complex environments, comprising multiple disparate security solutions, added over time to address various aspects of risk. Without strategic design, integration and visibility across the environment, these systems will not deliver optimal results and may even hamper risk mitigation.

Another challenge is the persistent cybersecurity skills shortage. Public-sector departments, like their privatesector counterparts, face an uphill struggle to recruit and retain the high-level cybersecurity skills needed to stay ahead of ever-changing cybercrime.

There is no silver bullet that will instantly protect organisations such as these. Developing effective solutions requires taking a consultative approach, where we understand their current level of maturity, use proactive assessments to expose vulnerabilities, address low hanging exposure for quick wins, and develop a sustainable plan to improve the organisation’s risk profile over time.

Important measures to mitigate risk also include the introduction of zero trust strategies, monitoring and evaluation, and the implementation of a Security Operations Centre.

1 https://newsroom.ibm.com/2022-07-27-IBM-ReportConsumers-Pay-the-Price-as-Data-Breach-Costs-Reach-All-Time-High

Our most important customer, is yours.

Celebrating the Brandwacht pedestrian bridge

t least five people – including four children – have died trying to cross the R328 at Brandwacht, and countless others have been injured in vehicle collisions.

For a long time, the road was a dangerous one that residents had to face daily, walking from their homes on the other side of the R328 to reach retail outlets, the local primary school and a church.

Vehicles travel at high speed along this route, often ignoring the speed limit.

AFurthermore, because of the alignment of the road and the fact that people would cross at grade, forward visibility and stopping sight distance were poor, creating a lifethreatening hazard.

For Mossel Bay Municipality, the situation was untenable, and an urgent solution needed to be found. Subsequently, in April 2018, Royal HaskoningDHV was appointed for the design, procurement and construction supervision of the bridge after assisting Mossel Bay to secure Municipality Infrastructure Grant funding.

The goal was to create a structure with simple, elegant lines insofar as the construction methods would permit. Articulation of the bridge deck was therefore eliminated to save money and time, and avoid unnecessary adornment.

Engaging the community

Importantly, before construction commenced, community leaders, as well as the primary school principal, were consulted to determine the best position for the bridge

The opportunity to create jobs and new skills was also maximised via community participation goal targets. Local SMME subcontractors and labour were hired to collaborate on the project, while comprehensive training was provided in areas that included gabion construction, formwork, steel fixing, pouring of concrete, and working at heights.

Design considerations

The decks of pedestrian bridges are often very light and vulnerable to collision forces. So, to overcome this complication and go

Providing safe passage for the surrounding community, Mossel Bay Municipality’s Brandwacht pedestrian bridge serves as a prime example of how structural engineering design can blend with aesthetic elements to enhance mobility experiences. First and foremost, though, it was an essential intervention to minimise pedestrian fatalities.

above the required 6 m vertical clearance, the deck was built monolithically with the piers. The rationale behind this is that if a collision force were to strike the deck, the piers would also help keep it from collapsing. This approach also made it possible to eliminate two bearings per pier support, which decreases the need for future maintenance.

From a construction efficiency perspective, the formwork for the bridge deck was pre-assembled off-site. This maximised the opportunity to plan the actual erection and assembly, and minimised disruption to traffic.

Shapely soffits and wave elements

The design incorporates a security screen and cage. Smooth curves were added to give the impression that the cage gets

bigger as pedestrians get closer to the middle, which is usually where people feel the most constrained.

Since the cage was a prominent feature of the bridge, it was designed with an emphasis on aesthetics. The horizontal members are shaped like waves and painted blue to represent the ocean nearby. Additionally, the cage enclosure is made of a transparent material to ensure that the steel elements stand out and remain the focal point.

The cage has been left open at the top of the jack spans and closed over the main span traversing the road below. This also creates the impression of openness, rather than a hemmed-in feeling, while crossing the bridge.

Other noteworthy aesthetic elements include the curved deck soffit, providing smooth lines across the trunk road

A pedestrian perspective. The overhead cage is open to the sky at the entrances but closed at the point where the bridge crosses the road to maximise safety

KEY FACTS ABOUT THE BRIDGE

• The reinforced concrete bridge structure comprises a three-span, continuous, varying-depth T-beam

• The bridge crosses the R328 with a 16.6 m central span and 12.59 m jack spans

A pedestrian perspective. The overhead cage is open to the sky at the entrances but closed at the point where the bridge crosses the road to maximise safety

• It is perpendicular to the road with a deck depth of 1 m at the columns, while the midspan and abutments have a deck depth of 0.65 m

• The deck has a minimum vertical clearance to the soffit of 6 m

• The horizontal clearance is 3 m from the shoulder to the concrete piers on the R328

• The deck width between kerbs is 2 m

• Polycrete handrails were installed to a minimum height of 1 m

• The western landing consists of a 1:8 ramp and staircase access to provide accessibility from the northern and southern approaches

below, while radiused corners soften visible deck edges.

Community bridge safety

Completed in October 2021, the pedestrian bridge has made a lasting difference to the Brandwacht community, and especially the local children who pass through this portal every day to reach their primary school. It’s a classic lesson in road safety, and an outstanding example of best-in-class social infrastructure in practice.

ABOVE View of the cage highlighting the blue structural element that represents a sea wave

LEFT Residents on their way back home from the shops

TOWARDS A SUSTAINABLE ASPHALT AND BITUMEN INDUSTRY

The second SATBinderrr conference hosted by the Society for Asphalt Technology (SAT) in September 2022 was about sustainability, and for many practitioners a high point in a difficult year beset by bitumen shortages, a lack of infrastructure budget, and Eskom’s woes, among others.

SATBinderrr doubled in length to two days on 21 and 22 September this year, with a hybrid model that attracted 169 delegates at the physical conference at the CSIR International Convention Centre in Pretoria, together with another 111 online delegates.

The inaugural conference in 2021 attracted almost 250 online delegates and the large number of practitioners who returned in 2022 agreed that the content provided in the 31 presentations and two panel discussions took the coverage of what

is important in the industry to new levels of excellence and innovation.

“I am extremely proud of what Krishna Naidoo, the incoming SAT president, and his team managed to put together at SATBinderrr 22,” said Herman Marais, outgoing president, SAT. “The greatest achievement of this conference was the emergence of a new generation of road engineers and specialists with a passion for our industry. SAT Binderrr has now set the benchmark for conferences aimed at young and established professionals in the roads industry, which was evident in the average

age of the delegates. The vibrant young leaders soaked up all the knowledge and information that was presented.”

One of the highlights was an informal ‘Get to Know Louw’ session in which Louw Kannemeyer shared his professional career journey from humble beginnings in a small farm school in the Free State to executive: Engineering Services at Sanral today. This personal insight was a great learning experience for many, driving home the importance of passion and commitment among young people to sustaining the industry at a high level of excellence.

SATBinderrr 2022 in progress at the CSIR International Convention Centre in Pretoria

USA sustainability initiatives

Audrey Copeland, president and CEO of the National Asphalt Pavement Association (NAPA) in the USA, added an international perspective to the strong sustainability theme that underscored the conference. A highly respected leader in the international asphalt sector, Copeland shared some insights into the size and scope of the industry in the USA and steps being taken to mitigate climate change.

NAPA represents asphalt producers and paving contractors, and has more than 1 100 members nationally. According to Copeland, the US has some 3 500 asphalt production sites. More than 94% of the 2.6 million miles (over 4 million km) of paved roads in the US are surfaced with asphalt, as are 85-90% of all runways at the nation’s 3 364 commercial airports.

In 2020, more than 400 million tonnes of asphalt mixture were produced in the US – a significant step down from the 500 million tonnes per year achieved in the early 2000s. The industry employs about 750 000 people directly and indirectly.

Copeland pointed out that total annual expenditure on asphalt pavement surfaces, mainly funded by government, is US$25 billion (R455 billion).

One of NAPA’s main drives is towards sustainability and resiliency, a focus that began 10 years ago and is driven by a dedicated director of sustainability. “This focus is integral to efficient operations and reducing costs, as well as benefitting the environment,” she said.

A NAPA initiative launched in January 2022, ‘The Road Forward: A Vision for Net Zero Carbon Emissions for the Asphalt Pavement Industry’, calls on the US asphalt community to advance technologies, products and processes to achieve net-zero carbon emissions by 2050. “This multiyear effort will engage, educate and empower the US asphalt community to produce and construct netzero carbon emission asphalt pavements.”

Sustainability practices typically result in cost savings, and efforts to lower carbon emissions provide significant grant opportunities from the US government. ‘Buy Clean’ legislation is also being passed in several states, while federal agencies are also adopting Buy Clean policies. Sustainability initiatives are increasingly impacting the value of US businesses, along with their ability to recruit and retain employees and attract investment.

The power of recycling Copeland emphasised that the initiative is being driven by NAPA’s members with the focus on education, science and engineering

rather than as a marketing exercise. She added that achieving net-zero production and construction will need buy-in from the entire US asphalt community – from producers to researchers to specifiers.

“The effort starts by focusing on the way we operate. In 2019, for example, the industry’s use of reclaimed asphalt pavement (RAP), and increased use of natural gas relative to the industrial sector as a whole, resulted in 2.9 million metric tonnes of avoided greenhouse gas (GHG) emissions, equivalent to the annual emissions of 630 000 passenger vehicles,” said Copeland.

“The progress in the use of warm-mix asphalt (WMA) technologies is another great example of the partnership between agency and industry.”

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Herman Marais, outgoing president, SAT

Nishaat Mowzer, focus area chair: Seals, SATBinderrr

Audrey Copeland, president and CEO of the National Asphalt Pavement Association in the USA

SIMPLICITY,

The impact of RAP utilisation has been significant in the USA. Estimates show that the use of RAP saved 24 million barrels of liquid asphalt binder, 82 million tonnes of aggregate, and $2.9 billion (R52.8 billion) in 2020 alone.

The same survey evaluated GHG emissions, finding that US RAP usage from 2009 to 2020 saved 23.5 million metric tonnes of carbon dioxide equivalent.

A 1% annual increase in RAP use nationally reduces 0.14 million metric tonnes of GHG emissions, equivalent to removing 30 000 cars from the roads in a year.

The positive impact of RAP use from 2009 to 2020, according to the EPA’s Greenhouse Gas Equivalencies Calculator, is equivalent to the amount of carbon offset by planting 388 million tress and letting them grow for 10 years. “Our efforts are akin to planting a tree for every man, woman and child in the US,” said Copeland.

“That’s only considering recycling. Imagine what our industry has achieved with all our energy and emission reduction efforts and technologies.”

Some technologies under investigation include quantifying the upstream impacts of additive production, new forms of asphalt binder and/or binder replacements, rapid assessment of new materials, education on use and acceptance of scope 3 emissions, performance tests leading to specification development that encourages innovation, and research allowing industry to increase RAP content to greater than 40%.

The US industry is looking to achieve resilience by using tools already available and expanding that toolbox. A few of those tools are rapid construction techniques that can

lead to rapid recovery, pavements designed for longer lives, climate adaptable materials designed to handle extreme temperatures, WMA allowing for increased haul distances, porous asphalt to manage stormwater, deep reconstruction with full depth reclamation, and cost-effective ways to strengthen pavement bases with asphalt overlay.

“Natural and nature-based features are paramount,” said Copeland. “Don’t design against nature; design with nature.”

Focus areas

Copeland’s words align closely with SAT’s strategic direction in South Africa and the call to action by its growing membership of asphalt and related practitioners. This was mirrored in the focus areas of SATBinderrr 2022 – Asphalt, Seals, Pavement Design and Binders representing the core of the asphalt and bitumen sector, and three additional focus areas, Recycling for Flexible Pavements, Chemistry for Roads, and Industry Disruptors, all directly associated with sustainability and resilience in the industry.

The focus areas were chaired by young professionals, who managed their portfolios and the topics presented with energy and passion outside of their day-to-day jobs.

Nishaat Mowzer, associate at Zutari and chairperson of the Seals focus area at SATBinderrr 2022, commented that the presentations were very relevant and well put together by the mainly young presenters. “There were some very innovative and interesting topics shared, for me, particularly around the bubble rising in seals with entrapped moisture in old surfacing and the need for a new test/spec for resealing after wet conditions, as well as the unexpectedly good performance of new-age modified emulsion slurries, and the work to improve the adhesion properties of anionic emulsion.”

Sponsors

The fact that SATBInderrr 2022 secured no fewer than 17 sponsors is testimony to the esteem in which this fledgling event is held. “It was a privilege to be involved in the SATBinderrr 22 conference,” stated Bennie Greyling, managing director of headline sponsor AECI Much Asphalt. “SAT has achieved its goal of creating a platform for young professionals to share their research and experience, and to grow their professional careers in doing so. The delegate profile also painted a bright picture for the future of the road engineering profession, with good representation from young professionals from all walks of life.

“The second SATBinderrr conference built on the good foundation of the first one and it is clear that the conference will grow from strength to strength and become a prominent date on the annual conference calendar,” Greyling concluded.

Presenters and focus area chairs gather on stage

Riverine management programme to assist with flood control

Agence Française de Développement (AFD) and eThekwini Metropolitan Municipality (EMM) are partnering to improve catchment management in Durban.

Cities and Climate in Africa (CICLIA) – a €12.4 million (R210 million) project preparation facility co-funded by the EU, the Swiss State Secretariat for Economic Affairs (SECO) and managed by AFD – is providing financial support for the City of Durban’s Transformative Riverine Management Programme (TRMP).

“This community-based urban river management system could set an important international precedent for urban river management,” says Geoff Tooley, senior manager: Catchment Management, EMM.

Sihlanzimvelo Stream Cleaning Programme

He explains that the torrential floods that had caused massive damage and loss of life in April had inadvertently assisted with the promotion of the TRMP to industry and residents by showing how the Sihlanzimvelo Stream Cleaning Programme (initiated in 2011), which formed the foundation for the project, had actually helped avoid damage resulting from heavy rains.

“Some 80% of blockages that led to massive infrastructural damage were caused by alien vegetation, with a far smaller portion attributed

to build-ups of solid waste such as plastics. Historically, culverts were designed using hydraulic capacity calculations and did not factor in the debris carried by rivers during storm events,” explains Tooley.

Areas managed under the Sihlanzimvelo Stream Cleaning Programme experienced little, if any, damage during the floods.

Sihlanzimvelo employs cooperatives of between eight and ten people from local communities to clear 5 km stretches of river, together with 3 m corridors on either side of the water, of alien vegetation and waste. They also report sewer leaks or blocked manholes.

Durban currently has 105 active coops that report to locally based assessors who are trained to both support these coops and assess their progress according to preagreed requirements. Each cooperative is paid a percentage of the fee due according to an agreed standard of cleanliness and river clearance achieved.

According to Tooley, Sihlanzimvelo had grown its reach from 295 km to 525 km, with ongoing work done in KwaMashu, Inanda, Ntuzuma and Umlazi creating clean public spaces that are now suitable for recreation. Around 800 jobs have been created and Sihlanzimvelo has saved the city millions of rand by preventing

Stream in KwaMashu under the Sihlanzimvelo maintenance programme where solid waste and alien vegetation were removed

additional damage to road culverts and associated infrastructure.

Financing

The C40 Cities Finance Facility has supported TRMP for four years. A resulting R8 billion business case and cost-benefit analysis has been done, illustrating how using a similar model to manage the entire 7 400 km of rivers and streams within the city’s boundaries could assist in future.

Future financing for the roll-out of a study and the development of an implementation and partnership plan will now come from CICLIA.

Zoé Ramondou, team project manager: Municipalities and Urban Development at AFD, notes that AFD is happy to support this initiative.

“We hope that the study we are funding will deliver very practical tools to facilitate planning and management of these catchments. We look forward to helping demonstrate that nature- and community-based solutions cost less, save a considerable amount of money by preventing damage and managing risk, with the added bonus of positive outcomes within the green economy through job creation. This project will also illustrate how these solutions can be combined with ‘grey’ infrastructure and improve efficiency and sustainability.”

Tooley points out that, in future, residents could expect climate change with hotter temperatures, more rain, rising sea levels and longer dry periods. “So, the flood risk is increased. We are worried that the problems we are seeing today are going to intensify and become more frequent,” he says.

Warmer temperatures would speed up growth of alien vegetation, which is shallow rooted and easily uprooted during storm events. This means more material for blockages of road culverts and more riverbanks exposed for erosion to occur. This increases the amount of silt in rivers.

Tooley notes that this alien vegetation also crowds out the indigenous, slower-growing, deeper-rooted plants. Deeper-rooted plants ensure better bank stability and therefore better protection for the property and infrastructure adjacent to the rivers.

He says that the economic benefits of this project included not only job and business creation, but also the retention of money in local communities, supporting local businesses, as people were able to work closer to home.

Additional project benefits include improved business skills as a result of training, and better community advocacy. Coops are empowered to educate their communities on more appropriate waste disposal as well as increased reporting of illegal dumping. In addition, communities are now growing vegetables on cleared riverbanks. The removal of vegetation has also reduced crime.

“The city has calculated that, if the project was rolled out over the full 1 200 km of rivers and streams crossing municipal land, this would provide an estimated R177 million in benefits to the city (at a cost of R92 million) and create 1 500 jobs. That is conservative. We haven’t even costed in the additional green economy opportunities. What this translates to

is that, for every rand that we are spending, we are creating benefits worth R1.92,” explains Tooley.

The next challenge is a roll-out of river management programmes across privately owned and tribal trust land. Research along the Ohlanga River (further extrapolated for the whole city, supported by the C40 CFF funding) revealed that R7.5 billion in public and private investment would be needed over the next 20 years.

“We would multiply that investment by 1.8 to 3 times – and that excludes green economy opportunities,” he adds.

These could include the growing of indigenous vegetation to replace alien vegetation in corridors, recycling and development of new products made from waste collected from rivers.

The next step is to identify partnerships and role players within three spaces – the Umhlangane River catchment, the Palmiet River catchment and the Umhlatuzana River catchment – and to develop on the ground implementation plans that will serve as a blueprint for businesses and property owners to fund cooperatives to clear rivers and streams on privately owned and tribal trust land. It is this important next step that is to be funded by the latest tranche of funding from CICLIA.

This has the potential to unite communities separated by apartheid-era town planning. “This programme could not only transform rivers but change our society. This will provide a scalable and replicable model for how cities across the world can manage and maintain their waterways while maximising socioeconomic benefits. Ultimately, we want to cover the whole city and the latest funding will enable us to keep this programme running. This is not a one- or two-year project – this is a forever project,” Tooley concludes.

Culvert at Caversham Road blocked with alien vegetation and solid waste during the April 2022 storm

Rehabilitating channels using a novel stabilisation approach

When five new and very active gullies formed on the Vergelegen farm in Somerset West, Western Cape, an urgent remediation response was required. A key challenge was that the watercourses had to be reshaped since the gulley sides were too steep to plant vegetation as part of a bioengineered response.

By Hans King, Pr Eng*

Cascades of small weirs were recommended to reduce channel slopes, as well as flow velocities during floods. The design objective was to keep the number of weirs to a minimum, both from a cost perspective and in terms of minimising the presence of intrusive engineered structures within the natural environment.

Erosion protection was required along the total fall of the gullies, with the drop height per weir, plus the slope of the channel between the weirs, determining how many were required. In terms of design options, configuring a steeper slope between the weirs would have reduced their number, in turn reducing construction costs. However, the downside is that a steeper slope between the weirs translates into higher flow velocities.

When planning a cascade of weirs, it is therefore important to find the optimum balance to minimise the risk of future erosion in the channels, especially during floods.

The dilemma when stabilising streams with vegetation

In the Western Cape, perennial wetlands and streams that are well vegetated with indigenous vegetation are quite resistant to soil erosion.

But when a watercourse (such as those at Vergelegen) has been severely disturbed, there is insufficient time within one growing season, including construction, to establish enough new vegetation to prevent the disturbed soil from washing away in the following rainy season.

An innovative approach

The novel solution to this problem at Vergelegen was to cover the base of the landscaped channel with a 150 mm thick flexible geocell mat. The initial intention was to fill this honeycomb structure with topsoil and densely vegetate it with plants, including palmiet reed. The latter tends to lie flat during floods and protects a lot of the soil adjacent to the plant from erosion.

Small-scale trials of this planted geocell technique were carried out on Vergelegen prior to agreement on the final design approach.

The result

Construction commenced on 1 September 2020 and the weir cascades for gully sites 1 and 5 were completed in the late summer of 2021. Indigenous wetland vegetation was planted immediately but did not have time to mature before the onset of winter.

The observed containment of erosion during the first rains was initially successful, especially where the plant density was high; however, in areas where plants were sparse, the topsoil started washing away.

In affected zones, once the honeycomb cells had been partially emptied of soil by erosion, piping underneath the mat became a problem and whole areas of the mat became devoid of soil fill. This was a problem particularly where the rehabilitated channel had to blend into the existing watercourse with short lengths of steep slope.

Late in the winter of 2021, some remedial work was done to the areas suffering from erosion. The then deformed mat was levelled and filled with a gravel and rock mixture. In addition, a shallow trench was dug at the mat joints (every 5 m down the length of the channel) and filled with gravel wrapped in a geotextile to cut off extended piping flow paths underneath the mat. Indigenous wetland plants were immediately planted in the gravel.

In addition to the general planting of vegetation, palmiet ‘logs’ (palmiet rhizomes

Severe gully erosion at Site 5 at Vergelegen farm

laid head to tail with a small overlap) were placed across the entire width of the channel every 2 m and staked into position. The key benefit of these logs is that they create surface roughness, which reduces the flow velocity in the channel. They also help to form a sequence of small pools that trap sediment and seeds, and encourage the establishment of new wetland vegetation.

Conclusion

The use of geocell mats at Vergelegen has proven to be very promising for future interventions. Based on the lessons learnt, and with hindsight, the upfront design would have included small cut-off structures under the mat, the filling of the mat with gravel, and the use of palmiet logs.

For future reference on other projects, it would also be valuable to research and quantify the allowable design channel flow velocities for a given fill material. This would enable the optimisation of the channel slope with the intention of minimising the number of weirs needed for the cascade.

*Managing director, HansKingSRS

INDIGENOUS WETLAND PLANT SPECIES EMPLOYED

The following plant species (which occur naturally on the farm) were used:

In the channel wet zone:

- Prionium serratum (palmiet reed)

- Carpha glomerata

- Ischyrolepis subverticillata (besembos) – transplanted clumps take a long time to establish

- Wachendorfia thyrsiflora

- Juncus effusus

- Juncus lomatophyllus

- Isolepis prolifera – this usually appears naturally and does not have a strong root system; however, it facilitates other plants in getting established, and creates a dense surface cover quite quickly

On the banks of the channel:

Ischyrolepis subverticillata (besembos)

- Pennisetum macrourum (African feathergrass)

Lower end of Site 1: for a short distance, the slope of the channel is 10-15% to tie in with the existing downstream channel. This caused an increase in flow velocity and erosion of the fill, requiring an alternative design approach

Representation of the impact that the number of weirs in a cascade has on the slope between the weirs

Filling the geocell mat with gravel

Attaching palmiet ‘logs’ to pegs

A cascade weir section with vegetation well established

A weir cascade installed on one of the remediated channel slopes

Gabion walls that retain the earth

The devastating floods experienced during 2022 in KwaZulu-Natal and other parts of South Africa have highlighted the importance of effective stormwater management. Among the most durable, sustainable and cost-effective are environmentally engineered solutions, says Louis Cheyne, managing director of Gabion Baskets. By Alastair Currie

Subject to ongoing erosion, even the best compacted earth embankments will progressively lose their structural integrity over time where poor drainage is a factor. Add a severe storm event, and the results can be sudden and catastrophic. For applications like road embankments and bridge abutments, precast concrete retaining block (CRB) systems are a popular choice for mass gravity walls. Another equally popular and globally applied approach is the specification of gabion systems.

When designed, manufactured and built by industry experts, their steel wire framed and rock filled composition can provide the same or a similar engineered solution to CRB installations, combined with costcomparative advantages.

“The added benefit in the South African context is that gabion systems are labour intensive, creating much-needed jobs in predominantly unemployed communities, as well as fostering a new generation of SMME subcontractors,” says Cheyne.

The latter then have an opportunity to progress to higher levels, and more

multifaceted work, within South Africa’s Construction Industry Development Board grading system, allied and backed by the Department of Public Works and Infrastructure’s Expanded Public Works Programme.

Inspection services and project management

Celebrating its 16th year in 2022, Gabion Baskets, headquartered in Johannesburg and operating nationally, as well as into SADC via its dealer network, is a specialist

Initial site preparations for the mass gravity retaining wall. The excavation in the foreground makes provision for the installation of a 1.2 m x 1.2 m stormwater catchment manhole

The rock-filled gabion baskets are composed of Class A galvanised hexagonal double-twisted wire mesh

Installation of 400 mm diameter heavy-duty uPVC drainage pipe

manufacturer of gabion systems in all facets. These extend from gabion baskets and gabion mattresses formed using Class A galvanised double-twisted hexagonal woven mesh wire to systems assembled using weld mesh panels. Allied specialist solutions include the supply of integrated geotextiles.

Historically, Gabion Baskets has provided a site inspection service, combined with

technical recommendations. This information provides valuable input for the design engineer, where applicable.

“While an engineer’s certificate is not needed for every structure, it is a legal requirement for mass gravity walls above 1.5 m in height,” Cheyne explains.

Gabion Baskets now also supports its multifaceted solutions with on-site

project management and construction supervision services, alongside formal training and mentorship programmes for SMME subcontractors.

“We’ve found that offering a project management capability passes on major benefits for the client, engineer and contractor in terms of ensuring a high level of overall quality for the completed installation,” Cheyne explains.

Built to specification Gabion structures may appear straightforward to construct because of the simplicity of the materials used; however, the widespread evidence of mass gravity gabion wall

A 400 mm diameter heavy-duty uPVC pipe passes through the base of the mass gravity retaining wall, feeding into a brick-built 1.2 m x 1.2 m stormwater catchment manhole (left). On the downstream end, another 400 mm diameter pipe section feeds downhill to a headwall

The wall at an advanced stage of completion

ASSAGAY ROAD, HILLCREST, KWAZULU-NATAL

FAIRVIEW,

LANDSCAPING

failures underscores the need for expert design and installation practices. Every step must be adhered to. This includes geotechnical reports to determine the soil characteristics, as well as laboratory tests to confirm that the selected structural fill below and behind the constructed wall has been compacted to 95% MOD-AASHTO.

Particular attention must be paid to drainage, which should always incorporate geotextiles – either woven (permeable) or non-woven (impermeable) – depending on the underlying geology and soil composition.

As Cheyne points out, gabions are naturally permeable because of their rockfilled voids. This has its advantages, but the degree of permeability needs to be controlled. For example, clayey soils will not suffer unduly from fines losses, so a woven geotextile is ideal. The opposite is the case for sandy soils, where a nonwoven option is best. Added to this, and depending again on the height, one or more stormwater pipes may need to be installed behind the wall, exiting at the base to facilitate smooth water run-off.

“Understanding how hydraulic pressures can build up behind a mass gravity retaining wall is a vital part of the stormwater design intervention. Installed correctly, the structure should remain sound and

Assagay Road

Putting these and other techniques into practice, Gabion Baskets is currently involved on a wide range of flood damage reinstatement projects within the eThekwini region. These include design input, product supply and project management on an approximately 9 m high gabion mass gravity wall in Hillcrest completed in October 2022.

“When the storm hit, the deluge of water caused a major embankment slope collapse, sweeping away a section of private road linking a residential dwelling,” says Cheyne. A consulting engineering firm, RJB Projects, was responsible for the design (see Figure 1), with the works constructed by an experienced environmental engineering contractor.

The wall incorporates specialist reinforced soil tie-backs using Gabion Baskets’ Gab-tail product. The latter is a standard rock-filled gabion basket with a mesh tail extended horizontally back into the backfilled embankment.

“For gabion structures higher than 4 m, and built in a fill situation, Gab-tails tend to be more economical and faster to install. The mesh tails improve the lateral

shear resistance (tensile strength of the soil), providing improved overall stability,” Cheyne explains.

The selected backfill should be composed of at least a G5 or G6 backfill gravel. To avoid damaging the mesh, individual aggregate sizes should also not exceed 150 mm. Typically, this sized material is compacted in layers of not more than 150 mm, normally to 95% MOD-AASHTO.

Landscaping

While gabions are excellent for engineered applications, they are also proving increasingly popular for landscaping projects, either using woven or weld mesh, the latter providing a far flatter profile with precise edges.

“You could build a mass gravity wall using weld mesh if a specific aesthetic effect was required, but the costs would be higher than for woven mesh gabion systems,” Cheyne continues, adding that the most common weld mesh applications are for architectural cladding, freestanding feature walls and landscape terracing.

“However, each project is unique and it’s increasingly not uncommon for designers to explore hybrid options that combine engineered and architectural gabion elements to maximise the natural appeal of wire and stone,” Cheyne concludes.

A series of terraces have been formed using weld mesh gabions filled with multicoloured stones to create a camouflaged effect

The terraced gabion installation provides aesthetic, as well as erosion control, benefits

functional, even during extreme storm events,” Cheyne continues.

Why municipal projects should be wary of fine-grained sand

With low-cost housing developments and other infrastructure falling squarely on the shoulders of municipal engineers, they need to be aware of the dangers of fine-grained sand.

Most building projects need to achieve a certain density of ground conditions, but the occurrence of a soil horizon with a high percentage of very fine-grained sand can present a serious challenge. This is according to Brent Cock, principal engineering geologist at SRK Consulting.

“It is important that municipal engineers, developers and contractors specifically check for the presence of fine sand as early as possible in a project’s preparation,” says Cock, who has witnessed these conditions on various occasions in his career. The grain size that raises the most concern is below 150 microns in diameter – or 0.015 mm.

He explains that the central problem lies in the fact that the particle size falls very close to the boundary of silt-size particles. This is generally 0.075 mm, though the British Standard marks the boundary at 0.06 mm.

Silt is known to be moisture-sensitive and exhibit dilatant behaviour. This is the same process that occurs during compaction, which, coupled with a narrow optimum moisture content range, makes the soil extremely difficult to compact.

“Proper compaction is a key aspect of ensuring the integrity of geotechnical conditions in housing projects, roadbuilding and other related construction activity,” Cock explains. “Where the soil is present on a project site, the municipality or developer needs to identify this early on to mitigate and understand the potential implications.”

Importance of laboratory tests

The early identification of silty, very fine-grained sand needs to include appropriate laboratory tests, over and above proven field tests conducted by an engineering geologist, which will determine the percentage of the problematic grain size within a soil horizon. Professional testing is important, he highlights; although the soil often looks and feels like ‘sand’, its behaviour during construction could be quite different.

“Where compaction is attempted, the desired density is typically not achieved often due to inappropriate moisture content. This leads to a potential increase in the soil’s compressibility. Walking on this surface feels rather like an air mattress

– such is its sponginess,” he continues. “If you are not aware that this soil type is on your site, it could create considerable extra costs for the project down the line.”

Cock points out that the presence of a soil horizon with a high percentage of very fine-grained sand is not necessarily a project-stopper, though it will affect a project’s capital requirements.

Remedial measures

“At least if the problem is picked up early, appropriate remedial measures can be incorporated into the engineering design, which will feed into the final capital requirements for the project,” he explains.

In some cases, it will be necessary to remove this material altogether, and to replace it with a more suitable one. Alternatively, it may be possible to rework the material and stabilise it with cement.

Another option may be to import and place a rockfill layer on which gravel layers can be laid. This is an effective solution if the soils are wet. However, the most cost-effective option will be determined by the conditions on-site.

“The risks can be mitigated and appropriate engineering solutions derived with a comprehensive site investigation at an early project stage – certainly well before the contractor is deployed to site,” adds Cock.

Structures from homes to roads demand solid ground conditions, he emphasises, and the cost of remediation after project completion can be high, often by orders of magnitude, and can cause considerable project delays.

“It is also vital to consider how good geotechnical information on ground conditions can benefit engineering design. The aim being to bring the cost of the project and an optimal engineering design as close as possible,” Cock concludes.

Brent Cock, principal engineering geologist at SRK Consulting

Particle size distribution showing the high percentage of very fine-grained sand and silt

GLOBAL LINING SOLUTIONS FOR LARGE INFRASTRUCTURE PROJECTS

Since its inception in 2002, AKS Lining Systems has grown to become a competitive global producer of thermoplastic lining products. Its products are exported to more than 30 countries worldwide where they are used in diverse applications such as mining, environmental conservation, water treatment and general infrastructure.

Situated in Cape Town, AKS Lining Systems offers strong support to the local South African and SADC regions.

Various containment and corrosionresistant solutions

According to Peter Hardie, technical and international sales manager of AKS Lining Systems, the company’s geomembrane range of products, Geoliner, is manufactured from HDPE or LLDPE resins that are considered chemically inert. This makes them the ideal choice as the primary and secondary lining systems in landfill sites. Geoliner is supplied in 7 m wide rolls, with various surface finishes, such as smooth, textured or mega textured.

In addition to the Geoliner range, the AKS Lining Systems flagship product is the AKS™ Corrosion Protection Liner. AKS™ (Anchor

Knob Sheet) is a liner extruded with a matrix of anchors. It is used extensively in acidproofing concrete structures by being cast into the concrete. The mechanical bond into the concrete means the product can be used in a vast range of applications, from mining to sewage treatment and large outfall sewers, to name but a few.

“The resins that we use are imported and are tried and tested to comply with the requirements for the GRI-GM13 and GRI-GM17, along with our own SANS 1526 requirements,” he says.

AKS Lining Systems is also ISO 9001:2015 certified, ensuring that management systems and quality procedures are maintained and reviewed at the highest possible levels. These systems and procedures follow through from resin suppliers, shipping and logistics, to finished product, testing and delivery.

The latest technology

AKS Lining Systems uses state-of-the-art, European-manufactured extrusion lines. These large extruders are designed to utilise the latest technology and operate continuously and faultlessly. “We can achieve extrusion accuracies close to 5%,

where the current market trend is within a 10% range,” says Hardie.

AKS Lining Systems also utilises lowcarbon emissions technology to power its plants. The Cape Town-based production plant has installed a solar facility along with generators to ensure continued production. The company also makes use of equipment cooling facilities that utilise non-potable groundwater.

Guaranteed quality

“Our logistical team ensures expert handling and loading of trucks and containers, along with all the required export documentation. For identification, tracking and traceability, all AKS™ and Geoliner rolls are individually labelled and numbered. Our manufacturing quality control (MQC) system ensures that we can trace each roll and its components right through from incoming resin to in-line production testing, QC testing and final MQC certification,” explains Hardie.

AKS Lining Systems has an open-door policy, allowing customers to inspect and review their product during manufacturing and testing, giving them peace of mind when materials start arriving on their sites.

Designing specifically for chemically aggressive environments, AKS Lining Systems supplies a range of lining solutions utilised extensively in infrastructure containment projects.

AKS textured Geoliner roll being coiled

FINDING FUNDS FOR

A greater focus and creative thinking are needed to make critical, but commercially problematic, water projects bankable. IMIESA talks to Amber Bolleurs, senior transactor: Infrastructure Sector Solutions Division at Rand Merchant Bank (RMB), about funding water infrastructure.

RMB strongly supports the development of water infrastructure. Water security is fundamental not only to the lives and health of South Africans, but to the growth and sustainability of our economy.

It is as vital as power, but unfortunately it has not received the same focus from the private sector to date. That said, we do anticipate more attention on water from both the private and public sector in the coming months,” says Bolleurs.

Traditionally, water infrastructure has been funded via a combination of on- and off-balance-sheet lending in the form of public-private partnerships (PPPs), as well as bonds or loans in the sustainability linked market. These financing structures are well established and should continue to be utilised to finance water infrastructure. However, Bolleurs believes that the industry needs to get creative with the financing of projects for struggling municipalities and water boards who still need to deliver critical infrastructure as part of their mandates.

PPPs to deliver water infrastructure

The South African PPP framework has been used with varying degrees of popularity to deliver public infrastructure since its establishment in 1998. Legislation such as the Public Finance Management Act (No. 29 of 1999) and Treasury Regulation 16 regulate national and provincial PPPs, with the Municipal Finance Management Act (No. 56 of 2003) in place to guide municipal procurement.

The Durban Water Recycling (DWR) Project is a great example. RMB assisted in structuring finance for the project in 2001. “DWR was one of the first PPPs within the water sector and, two decades later, it is still in operation. Two other thriving PPPs are Siza Water in Ballito and Silulumanzi in Mbombela. They are evidence that there is a case for PPPs as a framework and for procuring water infrastructure in the sector, and this model has been underutilised. PPPs are well suited to large projects like wastewater treatment, desalination plants and bulk water supply,” she adds.

The PPP model not only allows for the delivery of public infrastructure by the

private sector, without encumbering the public sector financial resources, but further adds a robust contracting structure. All institutions undertaking such partnerships require approval from National Treasury. All PPPs also go through regulatory tests (assess value for money, affordability and appropriate risk transfer) to check compliance before they are implemented.

However, Bolleurs cautions that the current procurement framework does not encourage the private sector to formulate and drive new PPPs. “This is because if a consortium pitched an idea for a PPP that was well received by the municipality or water board, it would be put out to tender, where competing consortiums could bid. This does not encourage innovation or new ideas from the private sector, who would need to put investment time, funds and energy into a pitch, only for their proactivity to result in a public tender. Therefore, government needs to drive PPPs.”

Traditional financing

Credit quality is a key factor when raising on-balance-sheet finance for a water project as this determines bankability.

Amber Bolleurs, senior transactor: Infrastructure Sector Solutions Division, Rand Merchant Bank

The Komati River

INFRASTRUCTURE FUNDING & IMPLEMENTATION

Producer Programme (REIPPP) projects. Instead of government providing water tariff breaks or direct funding by way of grants, they could provide direct support to a PPP-type model to make the project bankable. They could also partner with DFIs or the Infrastructure Fund to provide more levels of subordinated lending that attracts cheaper debt to make the project more affordable,” suggests Bolleurs.

REIPPP has attracted international interest and investment and has been an undisputed success story for the country by providing power and jobs. Conceivably, this model could be tailored for water – and we hope to see this thinking developed further by the Water Partnership Office.

Water Partnership Office

“A typical example of water projects delivered by way of traditional financing is the Trans-Caledon Tunnel Authority (TCTA). This is a great state-owned enterprise (SOE) that has delivered many successful water projects. They have good credit quality and as such do not have any problem raising funds from multiple sources. The SOE does not use traditional project finance, but a hybrid model,” explains Bolleurs.

She adds that RMB has a long history with TCTA. The bank served as principal funder for the Komati and Mokolo-Crocodile pipelines that deliver water to critical power stations. “They have a large project pipeline and we will continue to support them going forward.”

Large metros (like City of Cape Town and City of Joburg) as well as large water boards (like Umgeni Water and Rand Water) that are well run also manage to raise on-balance-sheet funding. Last year, RMB arranged R1.2 billion in sustainability-linked bonds, as well as a R500 million 10-year bullet bond for Rand Water. This marked two Africa firsts: Rand Water was the first stateowned company (SOC) to receive a sustainability linked bond and it was the largest South African rand denominated sustainability bond at the time. The bank acted as sole arranger and sustainability agent.

“Sustainability linked bonds or loans provide a different source of capital outside of the banks, such as pension funds, offshore companies and investors, and development finance institutions (DFIs),” states Bolleurs.

Making the ‘difficult’ water projects investment-friendly Given the very important obligation of the country to supply clean, potable water to all communities in South Africa, it is understandable that not all water projects are commercially viable, or easily banked. This, coupled with the tariff structure for water in South Africa, which for similar reasons can make cost recovery difficult, has resulted in a number of water projects stalling when attempting to raise financing. These projects require some creative thinking and collaboration with the private sector. Blended financing structures, government grants, DFI funding and other concessional or ESG funds should be leveraged alongside commercial funding to get these types of projects delivered. One possible solution could also involve explicit government support for water projects for the smaller, struggling municipalities and water boards, similar to what was done in the larger Renewable Energy Independent Power

The Development Bank of Southern Africa (DBSA) and the Department of Water and Sanitation (DWS) have established a Water Partnership Office with the aim of attracting private sector water participation in water infrastructure and its management. It will develop programmatic-type structures that assist in delivering on the broader National Water and Sanitation Master Plan (NW&SMP) framework.

“We are hoping that this office will develop programmes implementing the PPP framework in the water sector, as well as programmes around funding the more difficult water infrastructure such as reticulation and distribution,” states Bolleurs.

There will be a number of sub-programmes within the Water Partnership Office:

to scale and escalate water reuse projects across the country

non-revenue water, focusing on both physical and revenue losses

addressing wastewater treatment challenges

off-grid sanitation programmes

ecological infrastructure programmes

desalination

agricultural water-use projects

rural water supply.

“This development is very promising and we are excited to engage with the Water Partnership Office on this initiative.

RMB will continue to support water infrastructure projects going forward, and we are committed to developing solutions to address the water constraints of our country,” concludes Bolleurs.

The Durban Water Recycling Project

Natural pools – a water-friendly alternative

The installation of natural pools or ponds is an exciting lifestyle trend in landscapes, home gardens and public spaces. A natural pool is a type of constructed wetland that is implemented to purify and store water safely and effectively.

A typical residential swimming pool can hold anything from 20 000 to 80 000 litres of water. On the Highveld, a pool can lose up to 2 m of water a year from evaporation, while in hotter, more arid regions up to 3.5 m of water can be lost.

Natural pools are eco-friendly and do not require the use of chemicals. Integrated into the surrounding environment, they act as mini-ecosystems and can provide a habitat to a number of aquatic plants and animals. Besides providing an opportunity for the swimmer to indulge in pure, chemical-free dips, the natural pool can become a beautiful feature of any contemporary garden.

How do they work?

Using the concept of wetland or river ecosystems, natural pools use indigenous aquatic vegetation and simple filtration systems to clean the water. Beneficial

microorganisms are inoculated into the filter system to break down waste, which is then absorbed by the roots of the aquatic plants. As a result, there are no food sources to facilitate the growth of algae.

The natural system working around and, in the pond, consists of different filtering layers. There is a top wetland area – a large, raised plant box next to the pond which is filled with bog plants in a substrate of coarse bark and a thick layer of gravel. The stone and bark act as an anchor medium for the plants that create a habitat for the microorganisms that break down pollutants, while the gravel acts as a natural filter.

Water is continuously circulated and pushed through this wetland area over a small waterfall, which aids oxygenation, into a lower wetland zone, a beautiful water-lily pond apart from, but adjacent to, the actual swimming area. The water is sucked through the water lilies, another regeneration zone, which clears it of further

impurities before it is circulated back into the swimming area.

Benefits

Natural ponds provide a number of benefits, such as:

• providing a habitat for aquatic birds and animals

• extended storage of water for irrigation

• low cost due to low maintenance and operational costs

• removal of chemicals and heavy metals from water.

Maintenance of natural pools is easy –simply clearing the filter of leaves and other debris and pruning the natural vegetation once a month is enough to successfully maintain a functioning natural pool.

To reduce the costs of filling the pool with potable water, as one does with conventional pools, the efficient filtering and cleansing that occurs in a natural pool means that rainwater can be harvested to supply the pool. By using harvested water and solar-powered filter systems, a natural pool can be taken ‘off the grid’.

KSB calls for joint efforts to treat coastal waste

Addressing the challenge of industrial effluent entering our oceans, German original equipment manufacturer

KSB Pumps and Valves suggests forming partnerships that will ensure better quality management.

“There are a number of rules and regulations that businesses operating in South Africa’s coastal regions have to adhere to in terms of discharging industrial effluent produced during

manufacturing, processing and production. These businesses also have to keep in mind that despite being permitted to discharge in our oceans, being environmentally sensitive is a key part of this exercise,” says Hugo du Plessis, senior project engineer, KSB.

Providing a holistic solution KSB has already initiated endeavours on a global scale with German and European banks and investors that specifically target

countries that would like to improve their water and wastewater infrastructure. The idea is to focus on those areas where industrial effluent is freely dumped into the ocean –under legislation.

“In the near future, the international team working on this project will meet with endusers in South Africa, namely businesses and municipalities, and start the process of possible funding for new projects or upgrades to existing infrastructure,” Du Plessis concludes.

TECHNOLOGICAL INNOVATION IN

INDUSTRY STARTS WITH

PRODUCTS.

•

mitigating

Pressure management for ozone water treatment

The treatment of water to potable standards is a complex process that often requires the addition of ozone, which assists in the elimination of contaminants, such as bacteria, viruses and metals. This must be done under strict safety conditions, as ozone can be reactive and corrosive.

VEGA’s pressure transducers play an important role in safe ozone generation, as well as in the production of potable water. The VEGABAR 82 was used in the ozone treatment of water from the Baden-Württemberg supply system in Germany.

Baden-Württemberg is one of the largest and most traditionally far-reaching water supplies. Around 250 cities and municipalities are supplied with about 90 million cubic metres of drinking water each year. Water is transported from the Danube valley at the city of Ulm via Remstal to Stuttgart, where it is then treated. This is done via a raw water pump that draws water directly from the river as well as a pressure pipe from the pumping station to the waterworks and the treatment facilities.

In peak times, up to 2 300 litres of river water per second can be converted to drinking water. Highly active oxygen (ozone) for oxidation and disinfection is added during the water treatment process. To ensure that pressure measurement in the ozone collection pipe and at other important measuring points is absolutely safe and reliable, the engineering department decided to use the VEGABAR 82.

HOW IS OZONE FORMED?

VEGABAR 82

The VEGABAR 82 is a pressure transmitter with a ceramic CERTEC® measuring cell and a ‘second line of defence’. This is an additional process separation by means of a gas-tight feedthrough above the process connection. Although the measuring cell is permanently resistant to ozone, the second line of defence provides an extra layer of protection against the leakage of ozone from the pipeline through the pressure transmitter.

In the VEGABAR 82 process pressure transmitter, the process temperature is measured directly behind the diaphragm of

the ceramic measuring cell. Even very fast temperature changes caused by changing media are detected instantaneously and electronically compensated. The user can thus be sure that the sensor is always delivering the correct measured value.

Ozone oxidises dissolved and particulate organic matter and kills or inactivates existing microorganisms.

Ozone is always formed when some form of energy decomposes molecular oxygen (O2) into individual oxygen atoms (O), which then react with O2 to form ozone (O3). This can occur through UV radiation, lightning strikes and also high-voltage electrical discharges. Because of its high reactivity, ozone is produced, transported and added to the water on the spot and in compliance with strict safety regulations.

The actual production process takes place in pressurised reactors, where electrical energy is applied to convert oxygen into ozone. Then, the resulting gas mixture flows into an ozone collecting pipe. The maximum ozone concentration is about 180 g/Nm³ at an operating pressure of 1.3 bar.

Injectors feed the ozone into the water, while mixers distribute the tiny ozone bubbles evenly throughout the water volume. The water remains in large containers for a few minutes, during which time oxidation and disinfection take place.

The key element of pressure instrumentation from VEGA is the CERTEC ceramic capacitive pressure measuring cell. It is more precise than monolithic ceramic measuring cells and boasts a significantly higher overload resistance. Moreover, it is characterised by industry-leading, long-term stability and high temperature resistance. To ensure the highest quality, VEGA develops and manufactures all the core technologies of its instruments in-house. This even applies to the ceramic capacitive CERTEC measuring cells, which are produced under ‘class 100’ cleanroom conditions.

Ozone generators

VEGABAR 82

The use of Zincalume ® coated steel panels and potable water liner within the structure gives SBS Tanks a lifespan of over 65 years

AN ALTERNATIVE TO CONCRETE WATER STORAGE

Traditional concrete water storage solutions are no longer the best solution for every application, even for wastewater or bulk water storage. Concrete reservoirs are very complex structures that involve a costly and time-consuming design, planning and construction process that also utilises a great deal of water,” says Mava Gwagwa, director: New Business Development, SBS Tanks.

eMalahleni Local Municipality

In the Nkangala District of Mpumalanga, eMalahleni Local Municipality required a cost-effective and quick solution to increase

bulk potable water storage for the KwaGuqa township, situated west of eMalahleni.

“The immediate need was to increase bulk water storage between the existing 10 million litre concrete reservoir and a 400 000 litre elevated tank, which gravity feeds to the community. As part of the first phase, SBS Tanks installed two bulk water tanks, with the combined storage capacity of over 6 million litres,” states Gwagwa.

The setup has been up and running effectively and SBS Tanks has recently installed an additional 9 million litres of storage capacity.

Due to age and decay, the existing water treatment plant will be decommissioned and

the three newly installed bulk water tanks, which store over 3 million litres each, will be fed from a new water treatment plant. Once this plant comes online, the SBS Tank ‘farm’ (where five blue SBS Tanks stand within a securely fenced plot) will come into play and feed into the existing supply network via the elevated tank to the community.

“Using modular water storage reservoirs from SBS Tanks gives municipal engineers and managers a fast and effective solution for bulk water storage at community level, for desalination plants, effluent processing and even for the built environment,” explains Gwagwa.

He adds that SBS Tanks are quick to install and can be commissioned immediately, with the cost being considerably less than traditional concrete structures. “SBS Tanks can be installed anywhere, no matter how remote the location. The use of Zincalume® coated steel panels and potable water liner within the structure gives SBS Tanks a lifespan of over 65 years.”

With over two decades of experience serving the water sector, providing water and liquid storage solutions to the municipal, mining, fire protection, commercial and agricultural sectors, SBS Tanks is ready to assist the municipal sector with its bulk water storage needs.

SBS Tanks can assist municipalities in giving communities access to water with a solution that has shorter turnaround times and is less capital intensive.

The solution provided by SBS Tanks to eMalahleni Local Municipality

Data transmission of the pressure sensor signal

Keller offers a service package ranging from pressure sensors to the finished web app that assists in creating a customised internet of things (IoT) solution.

Pressure sensor signals are processed and digitalised using an electronic circuit.

They are converted into a number (pressure) that can be retrieved via an interface. Other useful information can be taken from the pressure sensor in addition to pressure and temperature.

In many cases, too little attention is paid to the importance of an accurate, stable and reliable sensor. The sensor that records the data is one of the most important parts of the system because decisions are made and actions taken based on this sensor.

Remote transmission

The transmission of recorded data is an important part of digitalisation. Sensors are often located in places that are far away from the central collection and evaluation point, or the sensors cannot be connected to a local communication network.

IoT is a global network that enables the exchange of data via the internet. This means that sensor data, for example, that has been generated at different locations around the world can be amalgamated in one system (cloud). A prerequisite for this function is that the device, the machine or the sensor has access to the internet.

Keller uses autonomous, battery-operated IoT devices that transmit data via various

radio interfaces. One advantage is that these devices can be installed with little effort, as there is no need for cabling and the measuring devices do not have to be incorporated into a company communication network. These devices and their batteries have a service life of several years, standardised radio technologies (LoRaWAN as well as mobile communications 2G, 3G, 4G, NB-IoT, LTE-M) with low energy consumption and a long transmission range of 15 km and over.

They are used alongside an intelligent, energy-saving electronics system. Whether LoRaWAN or mobile communications are used depends on the requirements for the data recording or on the type of radio coverage available on-site.

Data can be exchanged bidirectionally in both radio systems. Not only does this mean that measured values can be sent from the measuring point

to the central collection point (cloud), but communication from the central collection point to each measuring point is also possible. Communication to the device is used for configuration notifications, which, for example, change a measuring interval from a distance. The communication interface from Keller devices with LoRaWAN (ADT1), as well as mobile communications devices (ARC1), is well documented and a software sample code is available for integration into the company’s own application.

All devices are designed so that a software update can be installed. This is extremely helpful in the context of the extension of radio technologies or modifications of wireless protocols.

The electronics of the ARC1 mobile communications device for data transmission have a modular design and allow replacement of the radio module in the event of future technology changes so that the transmission device can be adapted again to the latest mobile communications generation with a small intervention and without having to replace the entire device.

Keller’s 36 XWei EX-rated submersible pressure transmitter

The site of the old Retreat Low Lift Sewer Pump Station in Cape Town is now home to tennis and netball courts, while adjacent to it is a new state-of-the art facility that went into service in mid-2021.

INNOVATION SHOWCASED ON NEW RETREAT PUMP STATION PROJECT

Forming part of the Cape Flats Sewage Reticulation System serving the Cape Flats Wastewater Treatment Works (WWTW), the old pump station had exceeded its design life and was unable to cope with peak flow conditions. This was exacerbated by high levels of sedimentation, rags and foreign materials in the inflow, which caused frequent clogging and pump blockages.

A further complication was identified when a condition assessment of the 1 050 mm diameter outfall gravity sewer downstream of the station feeding to the Retreat Main Pump Station revealed that an urgent intervention was required. The assessment, carried out by the City of Cape Town’s Water and Sanitation Department and BVi Consulting Engineers in 2018, indicated excessive corrosion up to 96 mm deep in the concrete pipe wall, with steel reinforcement in several sections exposed due to corrosive chemicals.

Additionally, the outfall line had silted up above 50%, significantly reducing the flow capacity. This, along with regular local pipe collapses on the outfall gravity sewer, resulted in continuous surcharging of manholes and regular incidences of sewage flooding the site.

Another key concern was the fact that a portion of the deteriorated outfall gravity sewer crosses

underneath a densely populated informal housing settlement. Ongoing pipe collapses therefore posed a high safety and health risk to residents.

Value engineering

BVi was subsequently appointed by the City of Cape Town to undertake the planning, design, tender documentation, project management and site supervision for the construction of the new Retreat Low Lift Sewer Pump Station, which is surrounded by a primary school, community hall, residential houses and flats.

The key components of the infrastructure upgraded entailed:

• construction of a pump station with a capacity of 750 ℓ/s peak flow

• construction of a grit chamber, plus the installation of automated screening equipment and an odour control system

• cured-in-place-pipe (CIPP) refurbishment and rerouting of the existing 1 050 mm diameter outfall gravity sewer

• demolition of the old Retreat Low Lift Sewer Pump Station.

The new Retreat Low Lift Sewer Pump Station was designed for energy efficiency, ease of operation and maintenance, high security, and aesthetic appeal. From an operational perspective, the facility features a conventional dry well (dry and

wet well) assembly running three immersible endsuction pumps (two on duty, one on standby) with variable-speed drives.

Telemetry and Scada systems were also installed for early detection and the relaying of signals and faults for off-site monitoring and rapid service response.

Overpumping and CIPP

At the onset, a precisely executed overpumping scheme was implemented to bypass the problematic outfall gravity sewer main between Retreat Low Lift Pump Station and Retreat Main Pump Station.

This intervention was designed to mitigate the ongoing risk of further pipe collapses and surcharging, which could have led to sewage flooding the new pump station construction site. The overpumping methodology established further ensured ready access for the rerouting and refurbishment of the outfall gravity sewer. This solution also negated the need for additional local overpumping during the CIPP stage of the project.

Forming part of the trenchless works, CIPP technology allowed for a 490 m section of the cleaned 1 050 mm diameter pipeline to be refurbished with resin-impregnated liner. In turn, the rerouted section was constructed using new

The new Retreat Low Lift Sewer Pump Station in the background. In the foreground are the tennis and netball facilities built on top of the demolished pump station

reinforced HDPE-lined concrete pipe. The old outfall gravity sewer underneath the informal settlement was abandoned.

Mitigating sewer spillage

A key challenge was experienced during the installation of a new flow meter to the existing 800 mm diameter rising main from Retreat Main Pump Station up to the Cape Flats WWTW. This required perfect coordination between the Sand River Pump Station, which discharges into the Retreat Low Lift Pump Station, and the Retreat Low Lift Pump Station, which discharges into Retreat Main Pump Station. A top priority was to ensure no sewage overflow and mitigate the environmental risk of sewage spillage into stormwater canals and vleis.

The three pump stations had to be pumped down to increase buffer and storage capacity in the upstream network to allow the team to complete the overpumping diversion and install the flow meter during off-peak, low-flow conditions within a limited time frame.

Deep excavation and dewatering

The underground section of the new concrete structure reaches depths of up to 9 m. During construction, this posed a major challenge because the high water table in the area sits at around 1 m below natural ground level.

To counter this, a cofferdam with wellpoint dewatering system was constructed from sheetpiles up to 12 m deep. The excavation process for the rerouting of the bulk gravity sewer also entailed shoring and dewatering of the trench excavation at depths of up to 5 m below the natural ground level.

The dewatering phase for the pump station was finally decommissioned after the below-ground reinforced concrete base, walls and ground level slab had been constructed and backfilled. This was a critical point, as the concrete structure needed to have sufficient weight before the water table could be allowed to rise without resulting in the structure floating due to buoyancy effect.

Corrosion protection

As is standard for pump station designs, the grit chamber and inlet works will be permanently exposed to corrosive gases from the raw sewer. Protection of the internal walls and roof surfaces is therefore crucial for the durability and longterm maintenance of the overall concrete structure. Proactive design elements included the installation of anchor-knob HDPE sheets with excellent chemical resistance, which were cast into the concrete. The walls were finished with epoxy-modified cement protective coating.

Aesthetics with added security

Above ground, the pump station’s reinforced concrete structure was designed for maximum visual appeal, while factoring in the need for added security given the high rate of crime and vandalism in the area. External walls were constructed with colour-coded concrete recesses and fitted with concrete recessed lights to match the colours of the City of Cape Town’s logo.

All access doors and frames are steel. No windows were provided to the concrete structure, with wall openings and sizes kept to an absolute minimum. To ensure adequate fresh air supply and circulation, ventilation fans and air conditioning units were installed inside

PROJECT TEAM

Client: City of Cape Town Engineer: BVi Consulting Environmental: Silito Environmental OH&S: Safe Working Practice

Civil contractor: CSV / Mazarin JV M&E contractor: Tricom Africa

the reinforced concrete structure. Electrical junction manholes external to the pump station were also fitted with lockable covers to secure and protect cables.

Built for the community

First and foremost, though, the construction of the new Retreat Low Lift Sewer Pump Station was designed and delivered for the community. It is highly functional and cost-effective to run, with no smell, which is especially important when you live next door.

The facility’s new bio-trickling filter odour control system constantly processes the hydrogen sulfide gas build-ups that form in sewer systems and release it as polished air into the environment.

Then, as a contingency provision, a standby generator was installed for backup supply during power disruptions. And in the worst-case scenario, a 1 050 mm diameter emergency by-pass line was installed, which is capable of handling the full design flow in the event of total shutdown of the pump station.

In the meantime, the old Retreat Low Lift Sewer Pump Station has a new lease on life as a vibrant sports and recreational facility.

North-east view of the new

Lift Sewer Pump Station

Two

Dry

Odour control room

Ominous signs from HUNGER STONES

These stones were used to mark the water level as a warning to future generations that they will have to endure famine-related hardships if the water sinks to this level again. Today, over a dozen of these boulders have been exposed.

Alongside the stones, receding waters have revealed sunken ships, lost Roman villages and, in Spain, an ancient group of standing stones. At the same time, Pakistan is experiencing floods so overwhelming that they cannot find enough space to divert all the extra rainfall. Closer to home, 2019’s Cyclone Idai set records for its size and ferocity, not to mention the damage it wrought on Mozambique. And recent floods in KwaZuluNatal remind South Africans that we are also not spared from an increasingly volatile weather system.

We can manage water better

Fortunately, the hunger stones’ warnings are not quite the same today – we can feed the world, and we can manage water better.

There is still a lack of urgency around addressing water issues. There are clear signs that investors and markets agree on. Perhaps the most telling example is the performance of the S&P Global Water Index. This index tracks water-sector companies (water utilities, infrastructure, equipment and materials) from around the world. Since 2001, it has

outperformed the S&P Global Broad Market Index by more than three percentage points annually; this year, that figure is already at 5%.

Droughts and climate stress are not the only catalysts for water’s rising value. If anything, we grossly undervalue this resource. Only 3% of the world’s water is fresh – and more than two-thirds of that sits in glaciers. Supply struggles to keep up with demand as the world modernises. It is simple economics: high demand and low supply mean water is becoming more precious.

Though society’s treatment of water has not been commendable, we still have many chances to improve the situation.

Interventions include:

• Proactive maintenance: It is far more costeffective to capture and remediate water infrastructure problems early than make repairs or replacements later. Technologies such as acoustic leak detection and predictive maintenance systems can radically reduce the cost and increase the longevity of water pipelines.

• Repairing infrastructure: Most African countries struggle with large levels of non-revenue water wastage. Fixing this would save water and bring revenue to ailing municipalities.

• Decentralised water reuse: Industries can capture and recycle run-off water for site activities, and use technologies such as UV and ozone to create safe potable water for

their sites and surrounding communities. Residential areas can use greywater recycling to irrigate gardens.

• Improved irrigation: Agriculture takes the majority of available water in Africa, much of it groundwater, yet most is lost through evaporation. Investing in newer techniques such as drip irrigation will lead to huge savings.

• Water education: Educate people on how to use water more smartly.

• Water technologies: The water industry has developed incredible new technologies to help monitor, manage and improve water systems. From capturing water data for planning to retrofitting water and wastewater facilities with power- and costsaving systems.

Fortunately, there is much we can do. Let’s not lose faith and weep, as the hunger stones suggest. Let us tackle water’s most acute problems and start creating a world where it is our most valuable resource.

“Wenn du mich siehst, dann weine” (if you see me, then weep) is the message that was carved into stones that were embedded into a river during droughts between the 16th and 19th centuries in Germany and in ethnic German settlements throughout Europe. By Chetan Mistry, strategy and marketing manager, Xylem Africa

WATER FOR

Expansion into wastewater treatment

JoJo Tanks has evolved from a specialist tank manufacturer to a water solutions company, providing a range of products such as pumps, filters and sanitation products. Kirsten Kelly talks to Grant Neser (GN), MD of JoJo Tanks, about its purchase of Calcamite and moving into the wastewater management space.

What was the motivation behind the Calcamite acquisition?

GN We purchased Calcamite mid-2019 because it was part of our plan to grow the business beyond water storage into a full water solutions company. Calcamite provides practical, fit-for-purpose on-site wastewater and sanitation solutions. Water and sanitation are linked; without suitable wastewater management, we cannot have quality water. Like JoJo Tanks, Calcamite is a roto moulder. Calcamite products are competitive, and we believe that the demand for on-site sanitation and domestic wastewater treatment will continue to increase. Government is battling to maintain its current

wastewater treatment capacity and has limited funding to erect new wastewater treatment plants that cater for the growing demand from newly built houses.

What are some of Calcamite’s popular products?

Calcamite supplies a range of on-site wastewater and sanitation solutions –wastewater treatment plants, septic tanks, conservancy tanks, greywater solutions,

sand, oil and grease traps, and sophisticated sewage reticulation systems. The wastewater treatment solutions are growing in popularity.

Our range of Bio-mites consists of wastewater treatment plants that process wastewater (including black- and greywater) to a specified quality, typically to reuse for irrigation and other non-potable applications. The BM4 and BM10 are part of our standard range for domestic applications; however, we can create customised solutions that cater for up to 500 people.

Our solutions, primarily in polymer, are robust and cost-effective – up to a certain size (for 500 people). From there, it is more economical to have water treatment plants in steel or concrete.

Are there any common misconceptions that you come across from prospective clients?

Calcamite supplies products to individual

Aerial view of Calcamite products

Bio-mite BM4

Grant Neser, MD, JoJo Tanks

households and the lower end of commercial, industrial and agricultural industries.

The price of our Bio-mite products is sometimes compared to the price of a septic tank. Our Bio-mites include a septic tank, reactor, disinfection tank and settlement chamber. A septic tank does anaerobic processing but needs a French drain/soakaway that does the rest of the processing.

A septic tank is a simple solution, but it requires the correct ground conditions to manage the French drain/soakaway. It cannot be installed everywhere. The soil needs decent percolation that allows the partially treated wastewater to soak away and be treated by the soil and the various oxidisation agents within the soil. A septic tank cannot be installed with high water tables (this can create groundwater pollution) as well as clay soils that will not allow the water to soak away.

It is also important to use a septic tank that is the correct size (200 litres of waste per person per day). Water should only be retained in the septic tank for 24 hours. It is always better to install a bigger sized septic tank than what is needed, as de-sludging the septic tank can be done less frequently.

There is also sometimes confusion between greywater recycling and blackwater. Blackwater refers to waste from toilets and kitchen sinks while greywater is from baths, showers, bathroom basins and washing machines, and has less biological waste. Greywater is redirected to a greywater system where it is disinfected with calcium hypochlorite (a plantfriendly chlorine derivative) to remove pathogenic organisms such as E. coli. Once the water has been

disinfected, the submersible pump automatically switches on and pumps the water for irrigation.

Do your wastewater treatment plants require maintenance?

When using products that have biological reactors, one must consider the bacteria that consume the organic waste. Anti-biologicals cannot be flushed into the sewer system. Your wastewater treatment plants should not be overloaded, as it can damage the bioreactor. The plant should be used fairly frequently; if left unused for an extended period of time, the bacteria are likely to die.

Any final thoughts?

JoJo Tanks are optimistic of Calcamite’s future. It is a business with an excellent value proposition and we look forward to serving the communities that need our products.

Calcamite greywater solution

Calcamite septic tank

CIVILS 2000 ADDS SIX NEW JCB BACKHOE LOADERS TO ITS FLEET

Back in 1992, Cape Town-based business partners

Colin Shapiro and Rob Starke established a civil construction company. It was their dream to ensure that the business made it to the year 2000, which is why they called it Civils 2000.

buildings, bridges, infrastructure services, sustainable energy projects, township development and road construction to the final asphalt layer. Projects are backed by a comprehensive equipment fleet comprising excavators, compactors, backhoe loaders, graders, wheel loaders, recyclers, milling machines, pavers, rigid tippers and water trucks.

“We offer full plant hire solutions, both internally and externally, and our clients know that they can rely on our well-maintained equipment for maximum uptime,” explains Andrew Newborn, plant manager, Civils 2000.

Optimum equipment utilisation

Withstanding the test of time, Civils 2000 has not only passed that milestone but has grown exponentially into the third millennium. The company currently employs 170 permanent staff but depending on operational requirements – meaning employing more labour for specific contracts – that number easily swells to between 300 and 500. Living one of its core values of ‘unlocking potential,’ Civils 2000 prides itself on upliftment and training when employing people, as well as when mentoring SMMEs and emerging contractors. Mainly tackling civil construction projects in the Western Cape, Civils 2000 has built a name for itself in housing and commercial

Civils 2000 adheres largely to its policy of running yellow equipment to the viable limit of its first life. For example, backhoe loaders and excavators are operated to 8 000 and 12 000 hours, respectively.

“We don’t only buy new equipment to replace older machines but may also want to increase our capacity, which is important to properly service a growing client base and project order book,” Newborn continues.

This was the case recently when Civils 2000 took delivery of six new JCB 3DX Eco backhoe loaders from Bell Equipment. Four were replacement machines for previousgeneration JCB 3CX models, while two were acquired to expand the fleet.

Civils 2000 has had a long and happy relationship with JCB backhoe loaders.

L-R: Justin Williamson (workshop foreman, Civils 2000); Percy Edwards (plant maintenance and workshop manager, Civils 2000); Tyron Ravenscroft (sales manager: Coastal Region, Bell Equipment); Andrew Newborn (plant manager, Civils 2000); André Jordaan (sales representative, Bell Equipment); and Dirk du Toit (plant operator and utilisation manager, Civils 2000)

“We’re also pleased that Bell Equipment, a company we’ve had many pleasant dealings with over many years, is now the South African distributor for JCB equipment, as this means we can depend on reliable technical backup when working locally and in other parts of the country,” states Newborn.

Competitive equipment finance

To acquire six new JCB 3DX Eco backhoe loaders all at once takes more than merely relying on petty cash, but Newborn is quick to point out that the offer to purchase the machines through JCB Finance and Absa was unmatched in the industry. A generous amount of cash assistance sweetened the deal further to match the competitively low interest rate and reasonable terms. Newborn is of the opinion that the competitive pricing of the JCB 3DX Eco backhoe loader makes it an ideal machine for plant hire.

Going forward, August 2023 will mark Civils 2000’s 30th year in business – a successful track record underscored by its commitment ‘to build a better tomorrow together’ and backed by world-class products and solutions.

Meeting the exacting road design specifications, a Lintec CSM400 0 containerised asphalt plant has formed an integral role in upgrading a strategic section of the corridor connecting the Cameroonian cities of Douala and Yaoundé. The new works replace an older roadway that has been in place for over three decades.

Delivering the asphalt for Phase I of Cameroon’s first expressway

It was widely billed as the battle between Liverpool FC’s then finest strikers, as Sadio Mané (of Senegal) and Mo Salah (of Egypt) came face to face in the final of the 2021 Africa Cup of Nations (AFCON) football championship, held between 9 January and 6 February 2022. A capacity crowd gathered in the Olembé Stadium in Yaoundé, Cameroon, to watch the match, which saw jubilant scenes when Mané’s penalty gave the Lions of Teranga their first-ever AFCON trophy.

The route to Olembé Stadium, which housed 48 000 football fans, was kick-started by a Lintec CSM4000 containerised asphalt plant. The plant played a pivotal role in the construction of Cameroon’s first-ever expressway, connecting the capital Yaoundé with its largest city, Douala – home to the region’s major airport and largest port.

A trail between two cities

The rapid growth of traffic on the old National Road No.3 had long left it struggling to support the economic and population growth of the two cities. Once labelled the world’s sixthmost dangerous road, at one time it was even responsible for a third of the country’s traffic accidents – the combined result of high traffic levels and neglected infrastructure.

A brand-new road was urgently required and, in 2011, plans were confirmed for the construction of 196 km of six lanes of dual carriageway, divided by a 5 m wide median strip. This would not only reduce the total travel distance between the two cities from 265 km to 215 km, but also enable the implementation of a 110 km/h speed limit across the route.

In January 2015, China First Highway Engineering Company – a subsidiary of China Communications Construction Company – began work on Phase 1, which involved the construction of a 60 km stretch between Yaoundé and

Bibodi, plus 25 km of access roads connecting it with National Road No.3.

At 98% progress before the tournament began in January 2022, the next step was to finalise construction of functional infrastructure, including five interchanges, nine toll booths, three rest areas, two service areas and 11 river crossings.

“This was such an important project that the government made opening up the 60 km of Phase 1 a priority before the tournament began,” says Tony Liu, CEO, Lintec & Linnhoff China. “Progress had suffered from the frequent heavy rains and other setbacks, but of course our CSM4000 performed perfectly whenever it was called upon.”

Part of that flawless performance can be attributed to the mixing plant’s containerised design. The plant’s components do not just fit in the container, they are in-built within the container, which is 100% ISO certified. Hence the working components are protected from harsh weather, thereby greatly reducing maintenance demands while also offering increased security

by restricting access to just one lockable door.

We like to – move it!

The CSM4000 boasts an impressive output of 320 t/h of asphalt in batch sizes of 4 000 kg. Its containerised design enables it to be transported to other jobsites quickly and effortlessly as each container houses the key components, enabling the Lintec trademark plug-and-play installation.

Offering the fastest erection and relocation times of any large-capacity asphalt plant, no concrete foundations need to be prepared at the next destination due to the unit’s flat, rigid surface area, ensuring high stability on compacted soil. This saves cost and time during installation.

“It’s always rewarding to play a part in enabling such vital improvements to a country’s infrastructure. The old National Road No.3 was slowing the country’s growth, and the problem was only worsening as it struggled to cope with rising traffic levels,” adds Liu.

“Building Cameroon’s first expressway improved the lives of ordinary citizens through enhanced public safety, greater GDP and speeding up access between two major hubs,” Liu concludes.

The cost of Phase 1 has been estimated at between US$441 million (R7.9 billion) and $528 million (R9.5 billion). Phase 2, which will be executed under a public-private partnership to ensure a speedy completion, will cover the remaining 136 km to Douala at an estimated cost of $1.271 billion (R22.884 billion).

Tony Liu, CEO, Lintec & Linnhoff China

The Lintec CSM4000 asphalt plant’s components are built within the container, which is 100% ISO certified

THE FIRST LINE OF DEFENCE IS protection

Well-designed concrete structures, incorporating the best materials, will last indefinitely with the right upfront specification combined with ongoing maintenance over their lifespan. Alastair Currie talks to Jacobus Pretorius, technical services manager at Mapei, about concrete protection and repair solutions.

Helping to build the future since 1937, Mapei is an Italian multinational and pioneer in the adhesives and construction chemicals market, fielding more than 5 000 products for the building and construction segments.

The Mapei Group now has 91 subsidiaries and 84 production facilities in 35 different

countries, including South Africa. This operational footprint is backed by a comprehensive research and development programme focused on developing ecosustainable and -compatible products.

Mapei entered the South African market in 2007. Initially, this was a distribution strategy that subsequently led to the establishment of a fully owned

subsidiary in 2009 to target local and regional African markets.

Rigid and flexible coatings

“Within South Africa, a major focus is on Mapei solutions developed for asset management and maintenance within the infrastructure space for a myriad of concrete structures. Here, our rigid and flexible cementitious coatings are ideal both for new construction and reinstatement in terms of corrosion protection and waterproofing, together with an aesthetic and relatively maintenance-free finish,” explains Pretorius.

“A key area where our solutions can make a major difference is in the wastewater treatment works segment, which – as highlighted by the Department of Water and Sanitation’s recent Green Drop report – is generally in a poor state of health, requiring urgent remedial interventions,” Pretorius continues, adding that Mapei provides specialist advice as part of its holistic services.

Products designed to meet rigid specification requirements include Paniseal 88, a singlecomponent osmotic cementitious mortar suitable for contact with drinking water, which is employed for waterproofing masonry and concrete structures; and Planiseal 288, a two-component ductile cementitious mortar for waterproofing structures below ground level (such as basement parking) and for storage tanks.

Mapelastic series

In turn, there are three options available within the Mapelastic series. The original

Jacobus Pretorius, technical services manager at Mapei

A key area where our solutions can make a major difference is in the wastewater treatment works segment.”

Mapelastic product is a two-component, flexible cementitious mortar designed specifically for waterproofing balconies, terraces, bathrooms and swimming pools; while Mapelastic Foundation is a two-component, flexible cementitious mortar for waterproofing concrete surfaces subject to negative and positive hydraulic lift.

The most flexible solution in the Mapelastic series is Mapelastic Smart. This is a two-component, high-flexibility cementitious mortar, with crack-bridging above 2 mm when reinforced with Mapenet 150 or Mapetex Sel.

Mapenet 150 is an alkali-resistant glass fibre mesh (in compliance with the ETAG 004 guide) for reinforcing protective waterproofing layers, anti-fracture membranes and thermal insulation systems; while Mapetex Sel is a macro-holed, non-woven polypropylene fabric for reinforcing waterproofing membranes.

Highly corrosive environments

The tougher the environment, the more robust the solution, with Mapei fielding specialist protective epoxy coatings that include Duresil EB. This is a two-component, anti-acid epoxy paint modified with hydro-carbide resin for protecting concrete and steel surfaces, like rebar reinforcement.

“A step up from this is Mapecoat I 24, a two-component epoxy paint for anti-acid coatings on concrete surfaces. This chemical-resistant coating is ideal for wastewater treatment environments, including digester and clarifier refurbishment projects,” Pretorius continues.

Alongside coatings, allied products for total plant structural rehabilitation include repair mortars, non-shrink grouts and microconcretes.

BIM and life-cycle costing

From a Fourth Industrial Revolution perspective, Mapei is responding to the life-cycle management tools defined within the building information modelling (BIM) environment, specifically in terms of current and future maintenance cost projections. The requirement for asset owners to establish and routinely update asset management databases is a core part of that BIM process.

“Our role is to recommend product specifications and cost estimations in near real time for interim and total refurbishment applications using specified Mapei products,” Pretorius explains.

Training Academy

As part of its value-added services, Mapei established a Training Academy at its Germiston facility in Gauteng to support trades, contractors, as well as designers and specifiers. These courses are free and open to all interested parties.

“The pressures on the construction sector in recent years –further exacerbated by Covid-19 – have led to industry contraction and skills losses in specialist areas like concrete protection and refurbishment. A global player in this field, we are helping to empower and restore the balance,” says Pretorius. Course examples include the design and detailing of waterproofing joints, as well as best-inclass installation techniques.

“Across the board, all concrete asset classes need attention to remain structurally sound, whether it’s a marine quay wall, a bridge pier or a dam wall. The most sustainable approach is to adopt a systematic life-cycle programme that maximises asset life, keeping structures safe and fully functional for decades,” Pretorius concludes.

Stormwater revamp in Port Shepstone

Rocla’s unique Beany Block system, which is specifically designed to enhance roadway drainage, has been installed in the recent upgrades to Nelson Mandela Drive in Port Shepstone’s CBD.

Comments Pieter Bodenstein, managing director of Margate Construction, which was appointed to complete the Nelson Mandela Drive upgrades: “The Beany Block system is easy to install and offers an uplifting finish to the roadway. The system has been applied to both sides of the roadway. It is a very presentable and neat system, and we will be utilising the Beany Block throughout the project, which is due to be completed in February 2023.”

The Beany Block is a substitute for kerbs, stormwater pipework (channel equivalent to and replacing 250-300 mm diameter pipes), kerb inlets and parts of footways. The system also reduces contractual claims, as damaged services are less likely to occur when compared to conventional drainage since excavations involved in the installation of the system are shallow.

A strong and functional system

The system itself consists of a series of base blocks of standard channel section and top blocks of inverted channel section with an opening in one side face, collecting water horizontally into the channel section. When laid end to end, they form kerb and/or surface water drainage units strong enough to withstand normal traffic loading.

“We have supplied in excess of 1 000 of each standard top and base blocks, as well as mountable units for driveway access and special blocks that transition between standard and mountable to the Nelson Mandela Drive project,” says Ritesh Singh, sales consultant for Rocla, who is based in Newcastle, KwaZulu-Natal. (Rocla is part of the IS Group, which also includes Technicrete.)

Applications for the Beany Block are wide ranging and include: scenarios where high inlet capacity is required; wide carriageways; as a division between vehicle and pedestrian/bicycle lanes with drainage from both sides; parking areas, taxi ranks and bus depots, wash bays and vehicle service areas; median islands; industrial areas; plus drainage around buildings and walkways.

When laid end to end, the Beany Block system forms kerb and/or surface water drainage units strong enough to withstand normal traffic loading

IMESA AFFILIATE MEMBERSMESA IMESA

PROFESSIONAL AFFILIATES

AECOM

siphokuhle.dlamini@aecom.com

AFI Consult banie@afri-infra.com

Alake Consulting Engineers lunga@alakeconsulting.com

ARRB Systems info@arrbsystemssa.com

Asla Construction (Pty) Ltd johanv@asla.co.za

BMK Group brian@bmkgroup.co.za

Bosch Projects (Pty) Ltd mail@boschprojects.co.za

BVI Consulting Engineers marketing@bviho.co.za

CCG puhumudzo@ccgsytems.co.za / info@ccgsystems.co.za

Corrosion Institute of Southern Africa secretary@corrosioninstitute.org.za

Dlamindlovu Consulting Engineers & Project Managers info@dlami-ndlovu.co.za

EFG Engineers eric@efgeng.co.za

Elster Kent Metering Mark.Shamley@Honeywell.com

EMS Solutions paul@emssolutions.co.za

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GLS Consulting nicky@gls.co.za

Gorman Rupp Cordeiro@gormanrupp.co.za

Gudunkomo Investments & Consulting info@gudunkomo.co.za

Hatch Africa (Pty) Ltd info@hatch.co.za

HB Glass Filter Media info@hardybulkinglass.com

Herrenknecht schiewe.helene@herrenknecht.de

Huber Technology cs@hubersa.com

Hydro-comp Enterprises info@edams.co.za

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iX engineers (Pty) Ltd hans.k@ixengineers.co.za

JBFE Consulting (Pty) Ltd issie@jbfe.co.za

JG Afrika DennyC@jgafrika.com

KABE Consulting Engineers info@kabe.co.za

Kago Consulting Engineers kagocon@kago.co.za

Kantey & Templer (K&T) Consulting Engineers ccherry@ct.kanteys.co.za

Kitso Botlhale Consulting Engineers info@kitsobce.co.za

KSB Pumps and Valves (Pty) Ltd salesza@ksb.com

KUREMA Engineering (Pty) Ltd info@kurema.co.za

Lektratek Water general@lwt.co.za Makhaotse Narasimulu & Associates mmakhaotse@mna-sa.co.za

Mariswe (Pty) Ltd neshniec@mariswe.com

Martin & East gbyron@martin-east.co.za

M & C Consulting Engineers (Pty) Ltd info@mcconsulting.co.za

Mhiduve adminpotch@mhiduve.co.za

MPAMOT (PTY) LTD mpumem@mpamot.com

Mvubu Consulting & Project Managers miranda@mvubu.net

Nyeleti Consulting naidoot@nyeleti.co.za

Odour Engineering Systems mathewc@oes.co.za

Prociv Consulting & Projects Management amarunga@prociv.co.za

Rainbow Reservoirs quin@rainbowres.com

Re-Solve Consulting (Pty) Ltd maura@re-solve.co.za

Ribicon Consulting Group (Pty) Ltd info@ribicon.co.za

Royal HaskoningDHV francisg@rhdv.com

SABITA info@sabita.co.za

SAFRIPOL mberry@safripol.com

SAGI annette@sagi.co.za

SALGA info@salga.org.za

SAPPMA admin@sappma.co.za / willem@sappma.co.za

SARF administrator@sarf.org.za.co.za

SBS Water Systems marketing@sbstanks.co.za

Silulumanzi Antoinette.Diphoko@silulumanzi.com

SiVEST SA info@sivest.co.za

Sizabantu Piping Systems (Pty) Ltd gregl@sizabantupipingsystems.com

Siza Water (RF) Pty Ltd PA@sizawater.com

Sky High Consulting Engineers (Pty) Ltd info@shconsultong.co.za

SKYV Consulting Engineers (Pty) Ltd kamesh@skyv.co.za

Smartlock jp.alkema@smartlock.net

SMEC capetown@smec.com

Southern African Society for Trenchless Technology director@sasst.org.za

SRK Consulting jomar@srk.co.za

Star Of Life Emergency Trading CC admin@staroflife.co.za

TPA Consulting roger@tpa.co.za

V3 Consulting Engineers (Pty) Ltd info@v3consulting.co.za

VIP Consulting Engineers esme@vipconsulting.co.za

VNA info@vnac.co.za

Water Institute of Southern Africa wisa@wisa.org.za

Wam Technology CC support@wamsys.co.za

Wilo South Africa marketingsa@wilo.co.za

WRCON ben@wrcon.co.za

WRP ronniem@wrp.co.za

Zutari Rashree.Maharaj@Zutari.com

New products enhance and protect concrete floors

Sika SA has released two new flooring products designed for form and function. They comprise Sikafloor CureHard LI, a lithium silicate liquid hardener and densifier of fresh and hardening power-trowelled or polished concrete surfaces; and Sikafloor CureHard GL, a sealing lithium-silicate-based crystalline agent with high-gloss finish. The latter was used for the first time locally at Toyota Material Handling’s purpose-built facility in Gqeberha, Eastern Cape.

Sikafloor CureHard GL improves the durability and tightness of concrete surfaces by penetrating their texture and filling surface pores. In addition to dust reduction, the product is solvent-free, odourless, and makes treated surfaces much easier to clean.

Prior to the application of Sikafloor CureHard GL, a mechanical scrubber, using only water, was employed to softly wash the concrete floor at the Toyota Material Handling facility. The floor was allowed to dry before one coat of the product was applied with a microfibre mop.

Since the ideal drying time is 24 hours, this first coat was allowed to dry overnight. A second coat was then applied in the same manner and again given 24 hours to dry. The final result is an aesthetically pleasing finish.

A section of the treated concrete floor at Toyota Material Handling’s purpose-built facility in Gqeberha, Eastern Cape

Pervious concrete could reduce toxicity in urban run-off

With a very wet summer predicted for many parts of South Africa, increased use of pervious concrete and concrete block paving in urban roads and parking areas could play a major role in reducing toxicity in the country’s water resources.

He says the dangers of toxic elements forming part of flooding run-off have been shown in KwaZulu-Natal on more than one occasion, with various beaches closed because of dangerous discharge and spillage from inland waters into the ocean. Although not new – it was first used in the 1800s –pervious concrete is now globally receiving renewed interest because of intensified clean water legislation in many countries.

When it rains, it drains

Pervious concrete ground surfaces allow rain, municipal and domestic gardening water, and other water, to percolate through to replenish natural aquifers. Run-off from impervious surfaces, such as asphalt, sends grease and other harmful chemical products into surrounding rivers, streams and dams, while pervious concrete paving naturally filters out pollutants,” explains Bryan Perrie, CEO of Cement and Concrete SA (CCSA).

“It has attracted a descriptive advertising slogan: ‘when it rains, it drains.’ That is, in fact, what happens. As water soaks through the sub-base of pervious concrete surfaces, natural filtration takes place, which removes pollutants and impurities from the water,” says Perrie.

“Permeable paving can also, to a certain extent, prevent flash flooding by absorbing water rather than moving it into drainage or allowing it to build up on top of the surface.”

With municipal budgets now extremely limited, Perrie says that pervious concrete

or permeable block paving can be used for stormwater attenuation to replace retention ponds. This can reduce the number and size of drainage infrastructure elements, saving both materials and energy, as well as reducing future maintenance.

Among the major benefits of permeable concrete pavements is the natural drainage of standing water and puddles, which are difficult to prevent on large, flat surface areas. It also increases the safety of pedestrians because it dries rapidly.

Groundwater benefits

“The stormwater infiltrating through the ground provides higher moisture content. Moreover, the voids of the pervious concrete allow the necessary air for roots to breathe and grow into trees and plants. In low rainfall areas, pervious concrete can consequently increase the groundwater table,” Perrie continues.

Although not strong enough for heavytraffic pavements, pervious concrete has been successfully used for low-volume roads, driveways, sidewalks, golf cart paths, retaining walls, slope protection, and as French drains.

“The proper utilisation of pervious concrete is a recognised Best Management Practice by the US Environmental Protection Agency for providing first-flush pollution control and stormwater management,” Perrie concludes.

INDEX TO ADVERTISERS

Equipment

Nederland

Pumps

Valves

and Linnhoff Holdings

South Africa

Water

Corporate Services

Piping Systems

Consulting

Controls SA

Permeable concrete

Pervious concrete

Bryan Perrie, CEO, Cement and Concrete SA

It just makes sense.

SAFER ROADS = BETTER ROADS

Tra c Speed Deflectometer Device technology has become the global benchmark for assessing road networks. ARRB Systems Africa leads with the intelligent Pavement Assessment Vehicle (iPAVe) which is saving billions of rands to the fiscus and promoting a safer road environment. The iPAVe is a powerful tool that uses advanced technologies to collect and analyse full-spectrum road condition data that is critical for the e cient life-cycle management of road networks.

Benefits and uses include:

• Significant cost saving, per test/metre, over traditional structural testing methods - At Network Level, the cost per test/metre is almost 10 x less than the conventional methods, with similar savings being realised for Project Level investigations • The measured data is vigorously analysed and used towards safer road infrastructure • Collects all pavement surface and structural parameters with high accuracy in one pass • Ability to operate

at tra c speeds, improving production, safety and e ciency • Continuous structural measurements at significantly higher resolution than traditional techniques such as FWD, together with integrated surface and functional measurement, significantly reducing the risk of anomalous data • Provides comprehensive data to make informed decisions for financially and technically appropriate rehabilitation and surfacing treatments • Better QA/QC for road agencies, consultants and contractors promotes greater accountability.

Accurate, scientific measurements make it easier to proactively, rather than reactively, determine and implement maintenance strategies that are sustainable, thus preventing unnecessary expenditure. A well maintained, safer road network means a reduction in both vehicle operating costs and road related fatalities for South Africa.

Suite 1, Park 2000, 10 Kyalami Road, Westmead, Durban, 3610, South Africa www.arrbsystems.com Tel: +27 31 700 2500 Fax: +27 31 700 2550