IMIESA November/December 2022

The official magazine of the Institute of Municipal Engineering of Southern Africa

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.

www.infrastructurenews.co.za

Regulars

Editor’s comment 3 President’s comment 5 Index to advertisers

Consulting Engineers

HN Consulting Engineers celebrates 20 years of excellence in 2022 30

Water & Wastewater

Resilient gardens 33

Bigen delivers safe, reliable water to Palapye 34

Cape treatment works leads with energy-efficiency gains 37

Securing drinking water for communities 38 Transmission of recorded data 39

Hot Seat

Asphalt excellence is not a skill, it’s an attitude

Low-volume Rural Roads Investing in low-volume rural roads is crucial for South Africa 12

Smart Cities

The Joburg smart city approach 40

Sustainable Infrastructure

The efficiency of Terracrete permeable pavers 42

The acquisition of Kenzam Equipment to form Ammann Kenzam as a wholly owned entity of the Ammann Group represents a major milestone in the Swiss OEM’s ongoing penetration of the African market. P6

IN THE HOT SEAT

Roads are the backbone of every country’s economy, with South Africa’s ranked 10th in the world in size, with an approximately 750 000 km network – of which close to 160 000 km is currently paved. IMIESA talks to technical manager Robson Francis about National Asphalt’s role in providing sustainable road surfacing solutions. P10

Bitumen & Asphalt

AECI Much Asphalt’s Central Lab in a class of its own 15

State of South African Infrastructure Key findings of the fourth Infrastructure Report Card 17

85th IMESA Annual Conference

Proactive asset management and fiscal discipline key to municipal delivery 18

Renewable Energy & Electrification Project-managing a future green ammonia hub 24 Harnessing the power of the Malawian sun 26

Metering 24 months to go: if not reset, prepaid meters will stop working 28

Building Systems

The pros and cons of 3D concrete printing 44

Transportation

The need to establish sustainable economic corridors 45

Cement & Concrete

Building precast stadiums 46

Sustainability requires ethical practices 47

Readymix drivers play a crucial role in sound practice 48

A building plan for township communities 49

Culvert underpasses promote safe passage 51

Vehicles & Equipment

Mobile asphalt delivery from Brazil 52

BORDER

Secretary: Susan Canestra Tel: +27 (0)41 585 4142 ext.

KWAZULU-NATAL

Secretary: Narisha Sogan Tel: +27 (0)31 266 3263 Email: imesakzn@imesa.org.za

NORTHERN PROVINCES

Secretary: Ollah Mthembu Tel: +27 (0)82 823 7104 Email: np@imesa.org.za

SOUTHERN CAPE KAROO

Secretary: Henrietta Olivier Tel: +27 (0)79 390 7536 Email: imesasck@imesa.org.za

WESTERN CAPE

Secretary: Michelle Ackerman Tel: +27 (0)21 444 7114

Email: imesawc@imesa.org.za

A time for unity and sustainability

Across the world and in South Africa, we’ve all had to endure an especially challenging period since the start of the Covid-19 lockdowns. Russia’s invasion of Ukraine in February 2022 further exacerbated the situation, driving global fuel and food prices into super-heated inflationary territory. The last thing anyone needs is conflict. In fact, now more than at any other time in history, we need global unification and stability as we renew our fight against climate change. Keenly debated on the global stage at COP27 in Egypt, it’s clear that this threat cannot be ignored.

For this reason, citizens, industry and governments must stand together in a concerted effort to make the UN Sustainable Development Goals a widespread doctrine in practice. This is especially crucial given the world’s mushrooming population.

More people every year

In 1960, the global population was around three billion. Fast-forward to 2022 and the figure has now exceeded eight billion. It will rise to an estimated 9.8 billion by 2050, and 11.2 billion in 2100, according to a UN report.

Within our regional context, the World Economic Forum predicts that Africa’s urban population could triple by 2050 to around 1.34 billion. By then, Africa could be home to some 2.5 billion, with South Africa’s population hovering at 75 million.

From an African and international perspective, this has major implications in terms of competition for available resources. At the same time, there will need to be an increasingly intensive focus on infrastructure development to keep pace, while working to achieve net-zero emissions by 2050. It won’t be easy.

An accountability ecosystem

In the South African context, initiatives like the National Infrastructure Plan 2050 are critical in rapidly narrowing poverty, inequality and unemployment gaps. And that responsibility, working

in collaboration with the private sector, rests firmly with our three spheres of government (national, provincial and local).

Our future depends on a professionally qualified and dedicated civil service, and it’s great to see proactive steps being taken by leaders to ensure an efficient service delivery pipeline. A prime example is the stance adopted by Ms Tsakani Maluleke, South Africa’s auditor-general (AG).

In November 2022, the AG’s office released the 2021-22 audited outcomes for “national and provincial departments and their entities”. As for previous reports, there were concerns raised about wasteful expenditure and material irregularities, but these are being rigorously investigated.

On the upside, there have been positive gains, with 128 out of 424 auditees receiving a clean audit, compared to 117 out of 422 auditees for the 2020-21 period.

Of course, more needs to be done, especially regarding key strategic service delivery portfolios (like transport, and water and sanitation), as well as SOEs. Collectively, these entities account for more than 30% of the expenditure budget (estimated at R2.58 trillion for 2021-22), “but consistently have the worst audit outcomes.”

To gain positive traction, the AG says there’s a collective need for an accountability ecosystem and a culture shift. “A culture of performance, accountability, transparency and integrity should be a shared vision,” says Maluleke.

In my view, that’s a highly encouraging approach, and lays the groundwork for more coordinated infrastructure implementation going into 2023 and beyond.

In the meantime, though, I’d like to wish our readers an excellent festive season and a happy new year.

imesafsnc@imesa.org.za

PROFESSIONALISING THE MUNICIPAL ENGINEERING SECTOR

When I joined the Institute as a graduate member in 2007, I was in the initial stages of my career in municipal engineering, a field that I’m especially passionate about. Subsequently, I became an IMESA corporate member following my registration as a professional engineering technologist with the Engineering Council of South Africa (ECSA).

From there, my involvement in IMESA activities increased in parallel with the practical knowledge and experience I gained on a host of smaller- and larger-scale infrastructure projects. This growing capability, as well as my passion for mentoring young technicians and technologists, led to my appointment on IMESA’s Exco. My most recent position was vice-president: Technical Division prior to being elected as the incoming president for the 2022-2024 term. It’s truly a great honour.

Growing the network

First and foremost, IMESA’s mandate is to promote excellence in the engineering

BIOGRAPHY

Sibusiso completed his civil engineering studies from Mangosuthu University of Technology and professionally registered with ECSA in 2015. In addition, he completed a Global Executive Development Programme with Gordon Institute of Business Science –University of Pretoria. This programme is aimed at building future-fit, responsible leaders who can take their organisations to higher levels of growth and success in a globalised economy.

He has some 24 years’ combined experience, of which six were spent in the consulting engineering environment and the balance in the public sector in key roles that include senior manager: Water Construction at eThekwini Water and Sanitation, and head: Infrastructure Planning and Development, Water and Sanitation at uMgungundlovu District Municipality.

profession for the benefit of municipalities and their communities. To achieve this, one of my main objectives as president is to encourage all engineering personnel working at South Africa’s 257 municipalities to join IMESA, as either corporate (ECSA registered) or non-corporate members. The latter category encompasses graduate, student and associate members (such as financial officers and municipal managers who don’t hold a recognised ECSA qualification but have direct involvement in infrastructure project implementation.)

Benefits of becoming a member include IMESA training workshops and seminars at branch events hosted nationally, access to technical guidelines and design manuals, as well as bursary opportunities to study civil engineering. Then, of course, there’s the annual IMESA conference, which takes place next year, again during October, in Gqeberha.

Road to registration

Another of my objectives is to ensure that mentorship programmes are in place at

municipalities for all graduate engineers, technologists and technicians so they can become professionally registered. This is also a priority for ECSA, which has noted with concern the high number of graduates in the public and private sector who are not registered or working towards registration.

Registration is one of the milestones that all built environment professionals should achieve, and attaining this distinction is far more than just a tick-box exercise. It means that registered persons must take responsibility for the work they’ve approved. And that level of competency and accountability is essential for sound execution according to plan and budget.

Going forward, we must ensure the highest standards of municipal engineering excellence and being an IMESA member unites us in this common goal.

He is currently GM: Special Projects at Umgeni Water after close to four years leading the utility’s Infrastructure Development Division, which is responsible for water and sanitation infrastructure planning, water resources management, design, design review, project management, contracts management, health and safety, and environmental management.

Personal achievements include winning a SAICE 2018 Regional Technologist of the Year Award. Sibusiso is also a keen martial artist and currently graded as a third dan in karate. He has represented South Africa in international karate competitions and shares his passion for the sport as an instructor, particularly in the township environment.

For each of us, life is a journey and marked by key milestones in our personal life and career development. A case in point is my longstanding relationship with IMESA.

Sibusiso Mjwara, PrTechEng, MIMESA, MSAICE, MWISA, MIPET

AMMANN GROUP

invests in the future of South Africa and Africa

The acquisition of Kenzam Equipment to form Ammann Kenzam as a wholly owned entity of the Ammann Group represents a major milestone in the Swiss OEM’s ongoing penetration of the African market.

The fact that Ammann has been in existence since 1869 says everything about the Group’s sustained focus on strategic growth, and the formation of Ammann Kenzam underscores this,” says Rocco Lehman, managing director of Ammann Kenzam. “As in other parts of the world, it’s been an evolutionary process with far-reaching benefits.”

Lehman was responsible for establishing and heading up Ammann South Africa in 2010 to grow the OEM’s presence in the Southern African region for its road construction and allied machine range, as well as its batch and

continuous asphalt mixing plants – both mobile and static.

ELB Equipment was appointed as the dealer for its machine line, which includes compaction and paving products, while Ammann South Africa remained the direct customer interface until the appointment of Kenzam Equipment as its asphalt plant dealer in May 2020.

Kenzam partnership strengthens OEM capabilities

“Key motivating factors for appointing Kenzam Equipment as a dealer included their expert knowledge of the bitumen and asphalt market, with a proven track record in South Africa and Africa. Even more importantly, however, is the fact that Kenzam Equipment is a wellestablished and respected OEM in this field,” Lehman continues.

Based in Gauteng, South Africa, Kenzam Equipment specialises in the design and manufacturing of bitumen handling and storage systems, as well as fuel transfer, storage and fire protection equipment. Allied services include custom design, build and retrofit solutions for new and existing asphalt plants, plus plant installation and commissioning services.

Products produced by Kenzam Equipment include bitumen drum decanting units, bunded containerised bitumen storage tanks, cylindrical vertical and horizontal storage tanks, and bitumen pumping units.

A number of these products are similar to those produced under Ammann’s Complementary product range, which includes solutions like mobile laboratories, as well as bitumen processing, storage, and heating systems. An example includes the Ammann DrumTEK line of bitumen drum decanters.

“In addition to enhancing customer service, having a local fabrication capability in South Africa to support Ammann regional developments was seen as a major strategic advantage,” Lehman explains.

Ammann acquisition signed at bauma

The success of the partnership has now led to Ammann’s decision to acquire Kenzam Equipment to form Ammann Kenzam as a 100% Ammann Group entity. The agreement was signed at the Ammann Group stand during the 33rd bauma trade fair in Munich, Germany, held during October 2022.

“This was a proud moment for Kenzam Equipment. To be recognised for our homegrown expertise and to be accepted into the Ammann family is a great honour and one that is certain to take regional technical support capabilities to a new level,” says Richard Hurst, formerly a director of Kenzam Equipment and now COO of Ammann Kenzam.

“In addition to sales, our holistic solutions going forward will include retrofit upgrade

Celebrating the conclusion of Ammann’s acquisition of Kenzam Equipment are (from left) Andreas Aeberhard, Ammann Group executive vice-president; Richard Hurst, COO for Ammann Kenzam; John Lansdell, founder and head of Kenzam Equipment; Hans-Christian Schneider, CEO of the Ammann Group; Rocco Lehman, MD, Ammann Kenzam; Daniel Schneidewind, head of controlling division plants at Ammann; and Gunter Tesch, Ammann senior business development manager

Ammann’s ValueTec range is manufactured at its state-of-the-art facility in Mehsana, India. Shown here is a fully commissioned ValueTec 140 plant

options on older Ammann and other OEM asphalt plants, as well as full service and maintenance agreements. We’ll also be extending the Ammann Complementary line into the whole of Africa.”

Global production footprint with niche market focus

Depending on the product and market, machines and asphalt plants are manufactured globally at Ammann facilities based in Switzerland, Czechia, Germany, Italy, China, Brazil and India.

“The cross-pollination of research and development (R&D) within the Group means we can design products that meet specific country or regional requirements, without compromising on Ammann’s 153-year legacy for innovation and excellence,” Lehman explains.

“Markets in South Africa and Africa, for example, are far more price sensitive, while durability and ease of maintenance are other key requirements. For this reason, Ammann fields premium and value lines, and both have the same R&D DNA. For customers, the advantages include more straightforward processes and the ability to further customise with high-tech options,” Lehman continues.

Ammann India

Developing a value line was one of the key reasons for the Ammann Group’s initial joint venture and subsequent acquisition of Indian OEM, Apollo, to form Ammann India. During 2014 and 2018, Ammann invested some €95 million (R1.69 billion) in upgrading the original Apollo factory based in Mehsana, near Ahmedabad, to bring it in line with Ammann production standards globally. Today, the 120 000 m2 facility manufactures Ammann asphalt and concrete mixing plants, as well as Ammann asphalt pavers and compactors, destined for key markets like Southern Africa.

Examples of asphalt plants produced in Mehsana include the Ammann ValueTec range (80-260 tph [tonnes per hour]) and the CounterMix series (90-120 tph). The latter combines the simplicity of continuous drum-mix plants with exceptional fuel efficiency, thanks to counterflow technology. Meanwhile, ValueTec batch plants meet the requirements for cold or hot reclaimed asphalt feeds, together with either liquid or solid additives.

Alongside its ValueTec and CounterMix offering, during 2023 Ammann Kenzam will also be introducing the EcoTec (120 tph) batch plant into Southern Africa for the first time. A more affordable version of the ValueTec, there are currently two EcoTec plants operational in other parts of Africa.

Static versus mobility

Within the evolving market, mobile asphalt mixing plants are also gaining in popularity, particularly for shorter-term contracts where the cost of erecting a static plant is not justified. Mobile plants are also ideal for remote projects where haulage distances from fixed batch plants are too great.

In terms of mobility, Ammann has led with innovative solutions that include its ACM 100, 140 and 210 PRIME line, with production outputs of 100, 140 and 210 tph respectively. These plants, which are produced at Ammann’s factory in Brazil, are mounted on integrated trailers for towing by a truck tractor. The downside is that this Brazilian configuration setup is not currently road legal for South Africa without a rigorous homologation process, which entails mechanical modification. However, as the saying goes, “Where there’s a will, there’s a way.” So, Ammann and Kenzam Equipment put their heads together to engineer a solution.

In August 2022, this led to the launch of an Ammann CounterMix 120 unit mounted directly on to currently available road-legal trailer configurations in South Africa, ruling out the need for a homologation process. While the modular mobile trailer solution is custom built, the CounterMix 120 plant is 100% standard in accordance with Ammann’s OEM specifications.

“It’s an innovative breakthrough that has been celebrated throughout the Group as an example of out-of-the-box thinking – setting a new benchmark for Ammann mobility – and we’ve received a very positive response from the industry,” says Hurst, adding that the first mobile CounterMix 120 has already been sold to a Zimbabwe-based contractor, Exodus & Company.

Customers can order the basic asphalt plant only, or include allied elements like bitumen tanks and decanters, each of which will be mounted on its own separate trailer.

The ValueTec proposition

The Ammann Group’s gains to date have been

Ammann’s fully mobile and road-legal CounterMix 120 unit on display during a recent customer day

founded on remaining flexible, responsive and taking a long-term view guided by detailed market intelligence. The foresight of acquiring Ammann India is a prime example, which is yielding major dividends as the Mehsana factory continues to support Ammann Kenzam’s ability to field quality plants at competitive pricing.

Recent Ammann Kenzam sales in the past 12 months include four Ammann ValueTec static batch plants sold into the DRC. These comprise a ValueTec 180, two ValueTec 140s and a ValueTec 80. An Ammann ValueTec 140 has also recently been sold in Zimbabwe.

“The Ammann ValueTec series is a bestseller, with the core design sharing the same features as Ammann’s premium plant range produced in Europe. As per the product name, the ValueTec focuses on the essentials to offer exceptional value in terms of acquisition costs, as well as passing on significant operational savings in terms of greater efficiencies,” says Lehman.

Within the Africa Middle East region, Egypt has been a major growth market for the ValueTec brand, with 16 plants – ranging from 140s to 180s – sold by the local Ammann dealer during 2021 to support infrastructure development in Africa’s third largest economy.

“The history of Ammann is one of vision, innovation and excellence around the globe. The formation of Ammann Kenzam now opens a new chapter in the Group’s evolution in Southern Africa and Africa, which are among the world’s fastest growing regions,” Lehman concludes.

www.ammann.com

LESOTHO

Construction of Polihali Dam and Transfer Tunnel set to start

The contract amount for the Polihali Dam is approximately M7.68 billion (R7.68 billion). The successful Polihali Dam bidder is the SUN JV, comprising main partners Sinohydro Bureau 8 (China), Sinohydro Bureau 14 (China), Unik Civil Engineering (South Africa), and Nthane Brothers (Lesotho). Subcontractors include Melki Civils and Plant Hire (South Africa), MECSA Construction (South Africa), SIGMA Construction (Lesotho) and Kunming Engineering (China).

Construction will be supervised by the Matla a Metsi JV, comprising GIBB (South Africa), MPAMOT Africa (South Africa), Tractebel Engineering SA/Coyne et Bellier (France), and LYMA Consulting Engineers (Lesotho).

The Kopana Ke Matla JV – which will construct the Polihali Transfer Tunnel –includes Yellow River Company (China), Sinohydro Bureau 3 (China) and Unik Civil Engineering (South Africa), the main joint venture partners. Subcontractors include Nthane Brothers of Lesotho, as well as Esor Construction and Mecsa Construction of South Africa. The contract amount for the Polihali Transfer Tunnel is approximately M9.2 billion. Construction will be supervised by the Metsi a SenquKhubelu Consultants (MSKC) JV. MSKC comprises Lesotho-based FM Associates and South African firms Zutari South Africa, Hatch Africa, Knight Piésold and SMEC South Africa, the main JV partners.

Phase II adds 2 325 million cubic metres in storage capacity to the Lesotho Highlands Water Project (LHWP) and will increase the current annual supply rate capacity from 780 to 1 270 million cubic metres, contributing towards meeting South Africa’s increasing water needs. The additional flow of water from Polihali will simultaneously increase power generation within Lesotho towards meeting its domestic needs and reducing the country’s dependence on electricity imports.

A concrete-faced rockfill dam, the Polihali Dam is like the majestic Mohale Dam, which was constructed in Phase I of the LHWP. It will create a reservoir on the Senqu and Khubelu rivers, with a surface area of 5 053 hectares. The infrastructure also includes a spillway, a compensation outlet structure and a minihydropower station.

The Polihali Transfer Tunnel will transfer water by gravity from the Polihali to the Katse reservoir – the centrepiece of the LHWP. From Katse, water is transferred via the delivery tunnel to the ‘Muela Hydropower Station constructed in Phase I, and then on to the Ash River outfall outside Clarens in the Free State on its way to Gauteng. The Polihali Transfer Tunnel works also include: the intake works and gate shaft at the Polihali reservoir; the outlet works and gate shaft at the existing Katse reservoir, with underwater connection to the lake; as well as access adits to the waterway and associated construction infrastructure.

The envisaged transfer tunnel will be approximately 38 km long with a nominal bore of 5 m. Both tunnel boring and drill and blast methods will be used to excavate the tunnel.

NAMIBIA

Waste buy-back centres

People in the city of Windhoek will now earn money from the sale of their household waste at two new waste buy-back centres that have been funded by the EU to the tune of €2.12 million (R37.9 million).

The facilities will receive the waste, process it and use it as raw material to make other items. The aim is to recycle 2 000 tonnes of solid waste through the gradual deployment of 100 collection units under the Improving Solid Waste Management in Windhoek project. The project will also create jobs and raise awareness of resource conservation among 6 800 students.

“Population growth has led to an increase in the amount of waste generated each month, which in turn has put a strain on the capital’s landfills and shortened their lifespan. We are trying to limit the amount of litter in the city,” says Fransina Kahungu, chairperson: Basic Service Delivery Committee, Windhoek Municipality.

Delegates officially breaking ground at the sites for the two buy-back centres in Katutura

MOZAMBIQUE

Renewable energy can help build a reliable power system

Wärtsilä – a global technology group – released a study on two separate power system expansion scenarios. The objective is to assess the financial and environmental impact and amount of renewable energy capacity that should be built into the Mozambican power system each year, leading to 2032.

The pressing challenge for Mozambique’s energy authorities is to ensure that the entire population gets affordable and uninterrupted access to electricity over the next decade. To meet the projected 1.3 GW of electricity peak demand increase by 2032, Mozambique must build significant new power capacity. A further 2 GW would be needed to support the planned development of the Beluluane Industrial Park in the Maputo province by 2037.

Going forward, the development of new gas resources presents tremendous opportunities to rapidly increase gas-to-power capacity in the country. But Mozambique

can also rely on its wind and solar energy resources to rapidly increase power generation.

“Our study addresses some of the key questions facing energy authorities in Mozambique today, starting with the relative share that renewable energy should have in the country energy mix. Should Mozambique cap new renewable energy capacity to 100 MW each year as it currently wants to do? Or should it build more of it? What would the optimal power mix look like in each scenario? Answering these questions is crucial to informing power system planning and strategy in Mozambique,” explains Wallace Manyara, business development manager: Region South & East Africa, Wärtsilä Energy.

Wärtsilä presents and compares two potential power system expansion scenarios for Mozambique, one with renewable energy capacity additions capped at 1 GW by 2032, and the other where renewable capacity is allowed to reach 3 GW by 2032. Each scenario has been modelled with a worldleading power system modelling tool to identify the most optimal power

mix to be built year-by-year to provide additional electricity supply reliably and at the lowest possible costs.

The study reveals that the scenario featuring a high share of renewable energy in the power mix will be the most affordable and sustainable way to meet electricity demand over the next decade. Paired with energy storage and flexible gas engines to ensure grid balancing needs, maximising renewable energy will help reduce carbon emissions by 5 million tonnes by 2032. This will also generate savings of US$84 million (R1.44 billion) when compared to a low renewable energy deployment scenario.

The most competitive power expansion plan outlined in the report combines almost 3 GW of new wind and solar capacity, together with 1 GW of flexible gas projects, 205 MW of energy storage capacity, and 50 MW of new hydropower capacity. It also plans for 1 GW of baseload gas projects to be built from 2022 to 2032 – including the 450 MW Temane gas power plant expected for delivery in 2024.

Asphalt excellence is not a skill, it’s an attitude

What is National Asphalt’s niche market focus and operating philosophy?

RF Since inception in 1988, National Asphalt has been a market leader in the manufacture and supply of hot and cold mix asphalt products for the South African market. Our growth has been driven by an investment in technical expertise in conjunction with ongoing research and development (R&D) to provide sustainable solutions for any flexible pavement requirement, from low-volume roads to national highways.

Product excellence is a given; however, service excellence is even more important and is central to all we do. As testimony to this, over the years, we’ve retained and grown a loyal customer base.

What is National Asphalt’s current production capability and what types of fixed and mobile plants are employed?

We’re equipped to support customers nationally in South Africa. Our static commercial plants are based at Rustenburg, Laezonia, Bon Accord, Middelburg, Nelspruit, Vanderbijlpark and Portland. In turn, our mobile plants have the flexibility to support projects locally and cross-border, where we also have a commercial plant operation in Gaborone, Botswana.

In terms of combined capacity, our static and mobile plants are geared up to supply the market with at least 7 000 tonnes of asphalt per day.

How important is quality control and certification?

It’s essential and the foundation for excellence. National Asphalt is ISO 9001 certified, and we are currently preparing the groundwork for Sanas accreditation in terms of ISO 17025:2017. The latter standard covers the general requirements for the competence of testing and calibration laboratories and aligns with our strict adherence to quality control and ongoing R&D programmes.

Having these accreditations provides peace of mind for the client, knowing that the test results submitted for each batch of asphalt manufactured are exactly within specification. From our perspective, that’s equally important since some clients require a minimum fiveyear performance guarantee on hot mix asphalt formulations.

We also encourage and extensively participate in correlation testing with accredited laboratories to measure ourselves against industry benchmarks.

How will Sabita 35/TRH 8 influence future mixes?

The introduction of the Sabita 35/TRH 8 –Design and Use of Asphalt in Road Pavements manual advances the move towards performance grade (PG) specifications for hot mix asphalt in line with global best practice. The key focus is on ensuring asphalt longevity to maximise the return on investment for asset owners. Sabita 35/TRH 8 has already been implemented for Sanral projects, as well as by South Africa’s three toll road concessionaires. We are currently preparing our commercial sites to be Sabita 35/TRH 8 ready by running mix designs that we anticipate may be requested by the market. Each of these mix formulations takes upwards of 12 weeks to finalise, so perfecting the process up front enables more immediate delivery to market. Each of our commercial and mobile sites has a dedicated laboratory. All laboratories are equipped with basic Marshall testing equipment, while most of our commercial plants already have the latest industryspecific equipment to test according to Sabita 35/TRH 8.

Currently, our mobile plants are stationed at Aliwal North, Pienaarsrivier and Tzaneen in South Africa, as well as in Ondangwa, Namibia.

Roads are the backbone of every country’s economy, with South Africa’s ranked 10th in the world in size, with an approximately 750 000 km network – of which close to 160 000 km is currently paved. IMIESA talks to Robson Francis, technical manager at National Asphalt, about his company's role in providing sustainable road surfacing solutions.

What are some of the challenges in implementing Sabita 35/TRH 8?

Now that Sabita 35/TRH 8 has been introduced for current and future pavement mix designs, the industry will need to transition from the current Marshall stability method first introduced in the USA around 1939. In the interim, the South African roads industry has these dual-specification parameters, each of which requires different and specific test methodologies. However, the Sabita 35/TRH 8 test method is far more precise and uses the latest technologies.

PG is the future. Therefore, concerted training is required for universal adoption of Sabita 35/TRH 8 by all roads authorities and municipalities.

Are there any new developments in National Asphalt’s hot mix line?

The production of hot mix asphalt represents the bulk of our business activity. Most often, mix designs are contract specific, since each project has its own unique characteristics in terms of aggregate source, binder type and overall design. So, the client or engineer specifies the type of mix required.

Sometimes, we’ll work on a custom solution depending on the project complexity. However, to meet most project requirements, facilities like our Portland commercial plant have more than 40 off-the-shelf mix designs ready to go.

An exciting new R&D project is the development of our own proprietary PG specified UTFC (ultrathin friction course) brand, NATGrip®, which is currently in the certification process by Agrément South Africa. NATGrip passes on key benefits in terms of skid resistance and drainage, and has been developed based on our more than 24 years of applied experience.

NATGrip is open-end, area and traffic specific. For a high-trafficked road, we may recommend a modified binder and for a low-volume road, an alternative binder that’s more affordable and suitable. So, there’s great design flexibility.

In the meantime, NATGrip performance trials are being carried out on various high-volume roads, and the test results to date are very promising.

Our R&D team is also currently conducting in-depth laboratory studies on how compaction, asphalt type and binder type affects rutting and/ or stripping for hot and cold mix asphalt.

Where do you see the growth for cold mix asphalt?

Historically, the demand for cold mix asphalt –especially in the northern part of South Africa – has occurred during the summer rainfall season. However, evidence has shown that cold mix can be applied as an all-year solution for pothole repairs.

Given the extent of South Africa’s maintenance backlog, there’s huge demand for cold mix, from both contractors as well as roads authorities and municipalities. This is also being escalated by public pressure to address our pothole pandemic.

In response, we’ve developed our own unique product, NATPatch®, which is designed for highquality repairs to bituminous and concrete surfaces and one of our best-selling products in this segment. Certified by Agrément South Africa, NATPatch can be supplied in bulk loads, or in 25 kg and 30 kg bags, and is ideal for labourintensive construction.

From an R&D perspective, we’ve benchmarked NATPatch against similar products available globally and believe that our solution provides best-in-class performance and durability. Simply put, NATPatch is designed to meet three key criteria, namely ease of workability, a significant reduction in the degree of permeability, and longevity.

Furthermore, NATPatch is continuously graded and has been rigorously tested in terms of rutting and stripping performance. Once installed, we guarantee a minimum working life of two years. Clearly, the less time between repair intervals, the more cost-effective for municipalities, freeing up resources for other pressing social infrastructure priorities.

Is recycled asphalt (RA) a workable and sustainable solution?

Most definitely. The majority of our plants are RA capable and we’re in the process of upgrading the remainder. Going forward, the use of RA in asphalt should become the norm.

RA passes on cost savings and – more importantly – is eco-friendly. From a sustainability perspective, RA helps to increase the longevity of available aggregate resources and lowers the bitumen requirement.

While some might argue that a fresh virgin mix delivers the best results, it’s been proven that an RA mix can achieve the same or better performance thanks to innovations like binder rejuvenators.

And in closing?

National Asphalt is on a rebranding mission under the slogan, ‘Excellence is not a skill. It’s an attitude.’ We continually strive for excellence throughout the business and are committed to being at the forefront of quality – engineering the best mixes for South African roads. Our focus to become even more agile through improved mobility remains at the forefront of our business strategy.

Our employees are proud to be part of the National Asphalt family and to play an integral role in the future of South African roads. On that note, let’s hope the project pipeline increases exponentially going into 2023 and beyond.

National Asphalt

INVESTING IN LOW-VOLUME RURAL ROADS IS CRUCIAL FOR SOUTH AFRICA

Low-volume rural roads (LVRRs) account for some 80% to 90% of the road infrastructure in most developing countries and are therefore a critical conduit in enabling the achievement of the 2030 UN Sustainable Development Goals (SDGs). Despite this, the importance of LVRRs is often neglected and marginalised.

According to a UN Department of Economic and Social Affairs (UN-DESA) Policy Brief, an estimated 80% of people in poverty (defined as living below the US$1.90/day international income poverty line) live in rural areas. The situation is worst in sub-Saharan Africa, where more than 50% of the total rural population live in extreme poverty.

The situation is exacerbated by inadequate access to public services, infrastructure and social protection. In recent years, this has been compounded by the Covid-19 pandemic,

further reducing incomes, limiting mobility and undermining food security.

The UN-DESA identifies five broad lessons from countries that have succeeded in reducing rural poverty and inequalities:

• Invest in infrastructure and public services: Sustained investment in roads, electrification, sanitation, safe drinking water, education, healthcare and the bridging of the digital divide in rural areas is required. Such investment should also address inequalities in access to public infrastructure and services.

• Promote agricultural development: This

includes ensuring suitable access from farm to market.

• Ensure fair distribution of and secure access to land and its natural resources: As part of this, it is important that women in rural areas have equal access to land and natural resources, and to address discriminatory laws and practices that impede women’s rights.

• Improve social protection coverage in rural areas by modifying legal, financial and administrative barriers.

• End all forms of discrimination as this remains a persistent driver of inequality.

By Les Sampson, Dr Chris Rust & Michandre Smit

As is the case for most countries, the South African road sector is an integral part of the broader transportation network. The country has about 750 000 km of roads that include 131 919 km of unproclaimed roads almost exclusively providing access in rural areas. National, primary intercity roads (economic roads) are managed by Sanral on behalf of the Department of Transport, while secondary and tertiary intercity network, primary access and mobility roads are managed by the provinces. In turn, urban and rural municipal roads are managed by local authorities.

Of South Africa’s overall network, it is estimated that approximately 630 000 km (84%) are LVRRs defined as carrying less than 500 vehicles per day or less than 1 million E80s over a 20-year design period.

In general, the national road network managed by Sanral is in good condition. However, the state of provincial and local roads varies greatly. In many small towns and rural areas, the roads are in an atrocious condition.

According to the 2019 Stats SA country report, South Africa’s National Development Plan 2030 (NDP 2030) has a 74% convergence with the SDGs, so more attention to and investment in the LVRR network are crucial to stimulating rural economic growth. In fact, sustainable transport will enable the implementation of most of the SDGs through interlinkage impacts, especially SDG 1: No poverty and SDG 2: Zero hunger.

Sustainable

Mobility for All

A global initiative, Sustainable Mobility for All (SuM4All) was established in 2017 with an agreement that transport was a key component of economic development and

central to people’s quality of life. It brings together 55 public and private organisations and companies with a shared ambition to transform the future of mobility.

The Global Mobility Report 2017 benchmarked countries’ performances on mobility relative to four policy goals; based on the report, no country, developed or developing, has achieved sustainable development. As a response, in 2018, SuM4All began the development of a comprehensive policy framework to assist decision-makers and practitioners to identify gaps, necessary steps and appropriate actions to attain the SDGs and improve the sustainability of their transport sector.

The Global Roadmap of Action Towards Sustainable Mobility builds on six policy papers, which includes the Universal Rural Access (URA) paper (published July 2019). The latter states that 1 billion people in the world do not have access to transport, with the majority living in rural Africa. In terms of the relevant SDGs shown in Section 4, the Rural Access Index (RAI) for different countries ranges from 5% of the rural population who live within 2 km of an all-season road in some low-income countries to 99% of the rural population in high-income countries.

Figures from 2016 shown on the South Africa country dashboard of SuM4All indicate that the RAI for South Africa was 74%. In other words, 26% of the rural population in South Africa (as an upper middle-income country) live in excess of 2 km from an allweather road.

Universal rural access implementation

The policy goal of achieving universal rural access by 2030 is ambitious and

challenging, but achievable. The URA paper states that it will entail providing access for more than half the rural population in many developing countries, which may take 10 to 20 years to implement. In the process, substantial capacity building is needed to provide the skills required to implement LVRR programmes and maintain the network.

As an example of good practice, the URA paper cites the South African Department of Transport’s S’Hamba Sonke (Moving Together) programme. Introduced in 2011, the programme provides grants for labour-intensive road maintenance of secondary roads and rural roads, while requiring participating provinces and district municipalities to implement and maintain road asset management systems to support decision-making on road construction and maintenance.

The URA sections specifically relating to South Africa note that the country has pockets of good practice that should be built on to improve rural access to all areas. The URA suggests a fuel tax as a dedicated source of financing road maintenance.

In an ideal world, this could be an option. However, South Africa already imposes heavy taxes on fuel, which goes into the central fiscus for general government funding and is not dedicated to road maintenance.

Therefore, without the support and commitment of National Treasury to provide adequate funds for rural development and the required improvements for rural access and mobility, the country will continue to struggle to achieve the SDGs.

Sanral has an active research programme for South African roads and transport but, understandably, it first focuses on its own priorities. Therefore, to facilitate improvements to the rural road network, there

Les Sampson, director, Sampson Consulting

Michandre Smit, researcher in pavements, CSIR

Dr Chris Rust, managing director, Pavement Engineering Research Consultancy

needs to be a parallel research programme, managed through the Department of Transport, to support the rural network.

Technology interventions

The road ahead will be influenced by key factors. These include climate change, increasing resource scarcity (e.g. bitumen, sand and aggregates), capacity building and skills development challenges, the evolving political landscape, plus the advent of the Fourth Industrial Revolution with its impact on roadbuilding technologies, particularly materials. ‘Future-proofing’ LVRRs therefore requires a creative and flexible approach.

Appropriate and cost-effective design methods based on locally available materials not necessarily meeting traditional specifications should be considered for LVRRs, with spot improvements in vulnerable areas for climate resilience. The Rural Road Note 01: A guide on the Application of Pavement Design Methods for Low Volume Rural Roads (2020) published by the Research for Community Access Partnership (ReCAP) provides good guidance in this regard.

From a South African perspective, the DCPDN design method highlighted as one of the suitable methods in the road note is well used and pioneered in South Africa. The DCPDN design software was updated through ReCAP and is recommended for continued use in designing and upgrading LVRRs in the country. The software can be downloaded from the CSIR website.

Adaptations for more climate-resilient rural roads are becoming critical in providing allseason access. In this regard, the use and implementation of the Climate Adaptation Handbook and the Change Management Guidelines should be implemented in South Africa for rural LVRRs. The documents are available on the ReCAP website (research4cap.org).

Roadbuilding materials for LVRRs that are based on improving marginal materials to counter the scarcity of good-quality crushed

aggregates will also become increasingly important in the future. This could include nanomodified emulsions (NMEs), polymer modification and biocementation. Other salient points to note for the construction of resilient LVRRs include provision for:

• alternative materials for surfacing seals that are resistant to increases in rainfall, temperature and radiation caused by climate change

• improved labour-intensive construction technologies for construction and maintenance to assist with job creation

• improved design of bridges and culverts on LVRRs to take account of potential increases in rainfall and to counter flooding

• improved safety on rural roads through appropriate geometric designs

• improved condition monitoring techniques for LVRRs using technologies such as satellite imagery and drones

• the employment of appropriate and costeffective accelerated pavement testing (APT) techniques to evaluate the suitability of alternative designs and materials for LVRRs using a systemic approach that simulates the increasing effect of the environment related to traffic.

APT case study

The APT methodology has been used to investigate the performance of new pavement design and materials in South Africa over several decades. In a recent study using a heavy vehicle simulator (HVS), an NME was tested at road D1884 near Heidelberg. It was shown that stabilisation of available substandard materials using an anionic nanosilane-modified bitumen emulsion – compared with the standard approach of importing high-quality crushed aggregate – can lead to savings as high as 40% to 50% for equivalent performance. In addition, there was also a significant reduction in construction effort and time.

This road carried in excess of 5 million equivalent standard axles (ESALs) as applied by the HVS, which is more than adequate for LVRRs. This demonstrates the value of having an early evaluation of the likely performance of new materials using APT compared with the monitoring of long-term pavement performance sections that require several years to obtain usable results.

However, HVS testing is expensive and is limited in simulating the environmental conditions that play a more significant role under reduced traffic loads in the performance of LVRRs. For this reason, investigations need to be carried out into the development of an accelerated testing facility for LVRRs that would simulate temperature effects, rainfall effects, radiation and ageing of the surfacing more accurately.

In the interim, the development of the prototype Traffic Stream Simulator, which has a modular design and can be used over a short test section, may go some way to address the cost limitation associated with HVS testing.

Recently, a standardised APT protocol was developed. However, an LVRR-specific protocol needs to be added that addresses the balance between trafficking and environmental distress in the performance of LVRRs.

Conclusions

Based on the South African Country Dashboard of SuM4All (2022), the overall Sustainable Mobility Ranking is 79 out of 183 countries, with a sustainable mobility index of 47.5.

Going forward, the incremental opportunities to improve on these statistics will serve as a positive socio-economic catalyst as South Africa strives to interconnect its rural and urban centres. However, achieving high-quality LVRRs – and roads in general – is dependent on a sustained plan with adequate funding and suitable management to meet and surpass South Africa’s NDP-aligned SDG goals.

This is an edited version of a paper, entitled ‘What does the future hold for low volume rural roads in developing countries such as South Africa?’, which was presented at the 2022 SARF IRF PIARC 7th Regional Conference for Africa and PIARC International Seminar on Rural Roads and Road Safety. The full paper and list of references are available from the authors at lsampson@iafrica.com.

AECI Much Asphalt’s Central Lab in a class of its own

Cenlab, as it is known, has now taken a significant further step to become the only fully accredited bitumen and asphalt laboratory in South Africa, reports Bennie Greyling, managing director, AECI Much Asphalt.

Firyaal Moos, manager: Cenlab, elaborates that all the current specialised testing carried out at the laboratory has been audited and accredited in a step that ensures the facility is 100% covered by Sanas. This includes dynamic modulus and flow, Hamburg wheel tracker, fatigue life and dynamic creep, performance grade (PG) bitumen testing, as well as rubber testing techniques encompassing dynamic viscosity, flow, compression recovery, and ball penetration and resilience.

Extension of scope

“Cenlab has been Sanas accredited for a large number of test methods for the past 16 years and we have been audited every 18 months since then,” Moos explains. “However, testing methods have developed and changed over the years, and we recently applied for an ‘extension of scope’ to include the most recent test methods, as well as others for which we have not previously been accredited. These advanced asphalt and bitumen rubber test methods were the focus of the latest audit.”

Sanas accreditation begins with assessment of the laboratory systems, including staff, equipment maintenance, calibrations and verifications, followed by the test methods.

Additional test methods can then be included through the extension of scope process.

“Since August 2006, Cenlab has been accredited for Marshall testing, SANS bitumen test methods and SANS aggregate test methods. We included six additional PG bitumen test methods in April 2022, and the final eight test methods in October 2022,” Moos expands.

Correlation testing programmes

While the Sanas accreditation applies to an AECI Much Asphalt facility, subsidiary AECI SprayPave participates in its correlation testing programmes and Cenlab plays a major role in AECI SprayPave’s binder testing and product development.

“Our daily activities incorporate equipment calibrations and verifications, regular updating of test methods, and continuous staff training.

It is essential for us to keep up to date with the latest developments in specifications and testing regimes. Our Sanas accreditation also requires our involvement in both interand intralaboratory comparative testing programmes for all our accredited test methods,” Moos continues.

She points out that AECI Much Asphalt aims to provide its clients with world-class service and the peace of mind of knowing that test results are supported by stringent management systems to ensure quality and conformity.

“What Firyaal Moos and her team have achieved is truly remarkable and we are very proud of our flagship laboratory,” says Greyling. “AECI Much Asphalt has built strong, lasting industry relationships in the past 50 years and I believe Cenlab’s latest success will help to sustain these relationships.”

Moos attributes Cenlab’s longterm success as a Sanas-accredited facility to hard work and dedication, together with the best efforts of her team to keep pace with changes and developments in the industry.

“Teamwork is key, and every team member plays a very important part in ensuring overall success.”

Benoni Laboratory

The Benoni Laboratory in Gauteng has also been upgraded significantly in recent years to offer all of the most up-to-date testing equipment and techniques, and is well on the road to its first Sanas audit.

Adds Joanne Muller, technical manager: Inner Region, AECI Much Asphalt: “We are learning from the Cenlab team and will try to emulate their outstanding achievement in the near future.”

In 2006, AECI Much Asphalt’s Central Laboratory in Cape Town became the first asphalt testing laboratory in South Africa to achieve accreditation from the South African National Accreditation System (Sanas).

Cenlab team members involved in the Sanas accreditation ‘extension of scope’ at AECI Much Asphalt’s Eerste River facility in Cape Town. L-R: Jonathan September, Siya Sidinile, Firyaal Moos, David de Wet and Craig Cupido

Firyaal Moos performing a DSR test. Cenlab received accreditations for all DSR tests in April 2022

Demonstration of a Hamburg wheel tracker test

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Key findings of the

FOURTH INFRASTRUCTURE REPORT CARD

• Electricity: The findings here show that peak demand for Eskom electricity has declined slowly over the last 10 years. The 2022 IRC says it reflects the increasing unreliability of supply, rising tariffs and the greater availability of alternative sources of electricity. So, a D- is scored for Eskom’s generating infrastructure, and a D for local distribution. On the upside, Eskom’s transmission network scores a B.

Strategic implementation

The 2022 IRC team was led by convenor Sam Amod and research leader Dr Kevin Wall, who pointed out that, in each IRC, SAICE has progressively widened the scope of its scrutiny. In the 2016 report, 21 subsectors were covered, rising to 27 in the 2011 report, 29 in the 2017 rendition and 32 for the 2022 IRC. In the three IRCs prior to the 2022 report, the overall grades were a D+, C- and a D+.

“In this report, we introduce fire engineering, information and communications technology, oil and gas pipelines, as well as coastal infrastructure, and reintroduce fishing harbours to the portfolio. Our comments also touch upon the impact of global warming and other environmental factors on infrastructure,” explain Amod and Wall.

The scorecard is based on a simple fivepoint scale, namely A (world class), B (fit for the future), C (satisfactory for now), D (at risk of failure) and E (unfit for purpose). On the spectrum, a plus indicates ‘robust’ and a minus ‘fragile’.

Drilling down into key sectors

The following is a snapshot of some of the key sectors studied and their scores:

• Water: According to the 2022 IRC, the quality and reliability of water supply has decreased in small towns and rural systems. In contrast, the national water resources infrastructure system has been able to meet

the demands for which it was designed. Bulk water resources scores a D-, major urban areas a C+, and all other areas a D-.

• Sanitation (including wastewater): In this sector, some 16% of households still need improved sanitation. Major urban areas get a C-, while all other areas score an E.

• Solid waste management: There has been a slight reduction in the provision of refuse removal services in urban areas. However, in rural areas, there is a significant increase in indiscriminate dumping. Waste collection in the major urban areas scores a C-, while waste collection ‘in other areas’ is rated as a D-.

• Roads: Here, the consequences of the widespread underfunding of road maintenance and improvement are cause for great concern. National roads remain favourable with a B+, but paved provincial roads and paved roads in the major urban areas score a D. The grading for ‘other municipalities’ paved roads’ is a D-, while provincial and municipal unpaved roads get an E.

• Rail: As the 2022 IRC states, safety and security have deteriorated quickly, and fewer trains are dispatched yearly due to infrastructure, process and systems issues. Heavy haul freight lines and general freight lines get a B- and C-, respectively. In turn, branch lines and Prasa passenger lines each score an E. The star is Gautrain, with an A-.

Now that the data has been collated, the next step is the strategic implementation of the 2022 IRC, says John Kaplan, 2023 president elect, SAICE. “The overall goal is essentially to increase awareness and influence change for the better.”

Working within the three tiers of government, SAICE undertakes to engage with decisionmakers responsible for prioritising resource and budget allocations relating to infrastructure.

“The IRC’s value lies in its ability to inform and influence macro-level planning, lobby for funding and to highlight the actions that we believe are necessary to improve the condition of the nation’s infrastructure,” Kaplan concludes.

‘Adapting to our Changing World’.

By Alastair Currie

Proactive asset management and fiscal discipline key to municipal delivery

Sibusiso Mjwara, IMESA President for

Jacob Mamabolo, MEC for Finance, Gauteng Provincial Government (GPG), was the keynote speaker at the opening function on Tuesday evening, setting the scene for the conference, which ran from Wednesday 2 through to Friday 4 November 2022. MEC Mamabolo has a keen understanding of infrastructure’s crucial role in rebuilding the economy and creating jobs in the wake of the Covid-19 pandemic, having held previous GPG positions that include MEC for Infrastructure Development and MEC for Roads and Transport.

Gauteng represents the economic heart of South Africa and is also home to three of the largest municipalities, namely Johannesburg, Ekurhuleni, and Tshwane. “Historically, Gauteng was founded on the discovery of gold in 1886. However, with gold mining

no longer the mainstay of the economy, diversification into new industries like green hydrogen and electric vehicles is essential in terms of the UN Sustainable Development Goals, where engineers are central to finding smart, green solutions,” said Mamabolo.

“In the context of climate change, and the recent spate of severe floods and extended droughts in South Africa, engineers need to respond to a future full of unknown variables with innovative ideas. From government’s side, we need to invest more in infrastructure, and in parallel tackle the issue of corruption, and poor-quality construction,” Mamabolo continued.

“To achieve this, we need the support of built environment associations like IMESA to ensure that all registered professionals adhere to the highest code of conduct, and that infrastructure projects are delivered on time, within budget and to the highest

Attended by more than 500 delegates, the 85th IMESA Conference brought together industry experts from South Africa and across the world to share their knowledge, experiences and insights on the pressing challenges facing municipal engineering –under the theme,

standards. It’s also essential that every municipality has an experienced team of in-house engineers to ensure effective service delivery,” he added.

Capacity building, proactive infrastructure asset management, procurement and supply chain management, financial discipline, spatial planning, and re-engineering in the face of environmental impacts like extreme weather were common themes throughout the conference presentations. (The papers can be downloaded at www.imesa.org.za/ conference-2022.)

Among the highlights were international presentations from the Institute of Public Works Engineering Australasia (IPWEA), as well as the American Public Works Association (APWA). The event was also attended by board members from the International Federation of Municipal Engineering (IFME), with an address given by Ville Alatyppö, vicepresident, IFME.

Handing over of the presidential chain

The opening function marked the end of the 2020-2022 term for the outgoing IMESA president, Bhavna Soni, deputy head: Water and Sanitation at eThekwini, who handed over the chain of office for the 2022-2024 period to Sibusiso Mjwara, GM: Special Projects at Umgeni Water.

“As IMESA, our goal is to support our members across South Africa’s 257 municipalities to make engineering projects effective and efficient, which is vital for South Africa’s Economic Reconstruction and Recovery Plan,” said Soni.

“In this respect, effective coordination within the three tiers of government is essential to fund and enable a municipally engineered response. This has been well illustrated by the emergency repairs required following the Durban floods. Essentially, we need to find the gaps and close them, which is where our annual IMESA conference provides the perfect platform for knowledge sharing, as well as robust debate between public and private sector stakeholders,” said Soni.

“It’s been an honour to serve as IMESA’s first woman president and to hand over the baton to Sibusiso in taking forward IMESA’s mandate,” Soni concluded.

Mjwara is a seasoned municipal engineer with extensive infrastructure project experience. “As the incoming president, I would like to acknowledge Bhavna for her commitment and contribution, and congratulate the new IMESA Council and Exco elected for 2022-2024. Alongside the key IMESA initiatives already in the pipeline, one of my personal objectives as president is the ongoing professionalisation of the municipal engineering sector, especially among young engineers,” said Mjwara.

IFME

In his address at the conference, Ville Alatyppö, vice-president, IFME, stressed that expertise and knowledge sharing are crucial in engineering solutions that preserve the earth for future generations.

He currently holds the position of director: Street and Park Maintenance for Helsinki, Finland. He is also a board member of the Nordic Road Association, CEO of the Finnish Association of Municipal Engineering, and chairman of the Finnish Asphalt Association.

“IFME was formed in 1960, some 15 years after the Second World War, to help rebuild the world. Now climate change presents us with a whole new set of challenges, and we need to find the answers together,” said Alatyppö.

“In this respect, we were recently pleased to welcome Ethiopia and Mexico as new

Jacob Mamabolo, MEC for Finance, Gauteng Provincial Government, was the keynote speaker at the opening function

From left are Visvin Reddy, board member, Umgeni Water (Gold Sponsor); Ville Alatyppö, vice-president, IFME; Sibusiso Mjwara, 2022-2024 president, IMESA; David Jenkins, keynote speaker and CEO of the Institute of Public Works Engineering Australasia; Scott Grayson, CEO of the American Public Works Association; and Mthobeni Kolisa, chief officer: Infrastructure Services, Spatial Transformation and Sustainability at SALGA

Bhavna Soni, outgoing president, IMESA, together with Geoff Tooley, Exco member, IMESA – both professional engineers working for the eThekwini Municipality. Tooley won the Best Paper Award for an IMESA member

members, as we continue to expand the IFME network. Our relationship with South Africa is longstanding and we value their membership and involvement.”

One of the key benefits of being part of IFME is the exchange of best practices. While each country has its own set of challenges, common threats like climate change are universal.

SALGA

As in the rest of the world, establishing a coherent roadmap in South Africa depends on strategic local partnerships. Among the most important for IMESA is its engagement with the South African Local Government Association (SALGA). It’s a two-way exchange that has become even more vital as infrastructure deficiencies within some municipalities reach crisis proportions.

“IMESA has a major role to play in the rollout of the National Infrastructure Plan 2050, particularly Phase 2, which focuses on ‘distributed infrastructure’ within the municipal arena, as well as the effectiveness of Expanded Public Works Programmes,” said Mthobeni Kolisa, chief officer: Infrastructure Services, Spatial Transformation and Sustainability at SALGA.

“Municipal engineers will also be actively involved in terms of how towns and cities adapt to the Just Energy Transition as South Africa progressively moves away from a reliance on coal-fired thermal electricity to renewable and allied energy infrastructure,” Kolisa continued.

“Another key issue is the need to engage on the installation of intelligent infrastructure, and not just as a climate mitigation strategy. We need to combat the

This year’s conference featured a Knowledge Bar, enabling delegates to engage one-on-one with industry experts

BEST STAND AWARDS:

Single Stand: Gabion Baskets

Double, Triple or Larger: Water Research Commission

BEST PAPER AWARDS:

IMESA Member: Paper 7 –Geoff Tooley, ‘A transformative riverine management program: A business case for a nature based adaptation program to protect city infrastructure and so much more…’

Non-IMESA Member: Paper 2 –Tjeerd Driessen, ‘Qualitative flood risk assessments for 3 townships in Johannesburg using high resolution modelling’

water and electricity, as well as safeguard our current and future infrastructure investments against theft and vandalism. The implementation of the Critical Infrastructure Protection Act (No. 8 of 2019) is part of that process.

“In all areas, SALGA wishes to actively engage with IMESA to guide local government on the best possible engineering implementation of future infrastructure policy initiatives,” Kolisa concluded.

An Australian perspective Sharing an Australian perspective, David Jenkins, CEO of IPWEA, addressed delegates with a presentation entitled, ‘Climate Change, Technology and Stewardship – Adapting Infrastructure Assets for a Changing World’.

One of Jenkins’ main thrusts was on the need to factor in infrastructure adaptation in line with trends like demographics, the internet of things, urbanisation, and the ‘work from home’ culture induced by the Covid-19 lockdowns.

“Most countries around the world have short-term political cycles, while engineers need to think long term from an infrastructure planning perspective, and more so now because of climate change,” commented Jenkins, referring to recent widespread incidences of floods and bush fires in Australia that will influence future rebuild initiatives and designs.

Similar to South Africa, Australia has three spheres of government, namely federal, state and local government. As Jenkins pointed out, this can result in disconnects in infrastructure strategies.

By way of example, he said that recent bush fires in Australia had affected two states, resulting in extensive infrastructure damage, including the loss of overhead powerlines. During the rebuild, one state reinstated the powerlines with timber poles, and the other with precast concrete poles. “Clearly, the latter is more resilient in terms of future climate threats and reinforces the need for an aligned national infrastructure strategy that factors in resilience planning,” said Jenkins.

As Jenkins pointed out, disasters like the Genoa bridge collapse in Italy in 2018 remind us of the need to constantly monitor and maintain existing infrastructure. A key requirement is financial sustainability for ongoing maintenance funding, particularly within local government where the bulk of the assets lie.

“When it comes to funding allocations, engineers and infrastructure asset managers need to tell their stories and be heard by political decision-makers. It’s a communications trade-off between risks, costs and service performance of your assets,” Jenkins explained.

“The Australian government plans to invest some A$120 billion (R1.37 trillion) on infrastructure over the next 10 years. However, the focus shouldn’t just be on new construction. We must make sure that there’s an ongoing conversation around maintenance and renewal,” Jenkins continued.

Operations and maintenance performance issues are common in most countries to a greater or lesser degree. In Australia’s case, IPWEA recently completed a survey with the Australian Local Government Association that revealed that some A$51 billion worth of infrastructure assets were in a poor state of repair.

“The findings show that sound stewardship is essential and that starts with an accurate and up-to-date asset management register, plus an asset management plan that dovetails with long-term financial planning.

Engineering and finance must be aligned. Only then can it be determined if they are financially sustainable,” he said.

Now and in the future, technology will be a great enabler in terms of achieving

efficiencies. An example is street lighting – a major cost for municipalities and one receiving attention in Australia through smart technologies that optimise utilisation and promote sustainability. Another example is static and mobile asset tracking and monitoring using technologies that provide real-time condition data.

“In our changing world, we need to be looking 10, 15 and 20 years ahead to keep pace with evolving trends, like e-mobility. Essentially, spatial and policy planners need to understand how people will want to live, work and play in the future. They also need to consider who pays for the infrastructure and the implications for future generations. It all comes back to the long-term financial sustainability of organisations and entities,” Jenkins concluded.

Public works in the USA

Jenkins’ message underscores the fact that municipal engineers across the world face similar challenges, which was further reinforced by Scott Grayson’s presentation, ‘Infrastructure, Advocacy, and Funding: Now What Do We Do?’

Grayson, CEO of APWA, expanded on their advocacy work in the USA to promote the essential role of municipal engineers, together with the pressing need for increased national/federal spending allocations for infrastructure. APWA structures were established in Washington

DC, and Ottawa, Canada, to start the government lobbing process.

“Our starting point was to create policy statements to educate public decisionmakers down to the point where they had a clear understanding of what public works represents. We chose three focus areas, namely transportation, water and emergency management,” Grayson explained.

In parallel, APWA launched a campaign highlighting the role of public works personnel as ‘first responders’ especially in times of natural disasters. Mirroring Jenkins’ earlier comments, APWA also rolled out a ‘Tell your story’ campaign where municipal engineers shared their experiences and responsibilities.

To further rally their forces, APWA established a group of public works directors from US cities with a population of 500 000 or more. This influential lobby group then had sufficient clout to engage at the highest political circles within Washington DC, including the White House. The culmination of six years of APWA lobbying, in 2021, the US Congress passed a law allocating US$1.2 trillion (R20.4 trillion) for federal infrastructure spend over a five-year period. Some 14 different federal agencies will administer this process.

“Municipal engineers around the world need to keep on speaking out to ensure that policymakers recognise the essential

and enabling role of public works,” Grayson concluded.

Umgeni Water

Concurring with Jenkins and Grayson, Visvin Reddy, board member of Umgeni Water, pointed out that engineers are solution drivers. (Umgeni Water was the Gold Sponsor for the conference.) Reddy said capacitating municipalities and water boards with relevant talent and technical skills is crucial within the context of South Africa’s transformation agenda.

Showing the way, Umgeni Water will shortly be launching its own engineering training academy, based at its Cato Ridge facility in KwaZulu-Natal. The initiative is modelled along the lines of the IHE Delft Institute for Water Education in the Netherlands.

“This is a groundbreaking initiative and we’ll be looking to partner with organisations such as IMESA because we, like our international counterparts, focus on enhancing communication between engineers and politicians, so we’re all working as a team to finding solutions to our country’s problems, a prime example being non-revenue water and ageing infrastructure,” said Reddy.

The way forward

Across the board, coordinated efforts are key, with presentations by National Treasury and a panel discussion, entitled ‘Asset Management in Local Municipalities – is it Worth the Spend?’ providing a platform for healthy engagement. Unfruitful and wasteful expenditure remains a

burning issue in South Africa, as does poor budget provision based on a lack of available asset data. While intended to combat corruption, procurement spend is also hampered due to excessive red tape

As reported by the Auditor-General of South Africa, a high percentage of municipalities are financially distressed. Consumer non-payment of water and electricity services is a major concern. However, the underlying causes are far more complex and require urgent resolution. (Dr Kevin Wall’s conference paper, entitled ‘Concerning municipal maintenance expenditure’, drills down into the subject.)

Closing remarks

“Across the globe and in South Africa, high-performing local governments are the catalysts for sustained socio-economic growth in their respective regions. And municipal engineers are integral to achieving this,” said Mjwara in his IMESA presidential closing address.

“The action points from this conference will be revisited when we meet again at the 86th IMESA Conference in October 2023. In the interim, IMESA and its strategic partners will continue to work with all stakeholders in pursuit of infrastructure delivery. We need positive and proactive engagement to make the changes we want to see in South Africa, and the world. We also need to ensure that municipal engineering is seen as a worthy career if we want to attract and retain experienced and aspiring professionals,” Mjwara concluded.

Emerging green hydrogen company Prieska Power Reserve – a collaboration between the Industrial Development Corporation, Mahlako a Phala and the Central Energy Corporation – is developing the Prieska Power Reserve (PPR), a green hydrogen project located within Siyathemba Local Municipality.

Project-managing a future green ammonia hub

Acatalytic project geared towards promoting economic growth and development in the Northern Cape, PPR will start producing green hydrogen and ammonia in 2026 through a combination of high-yielding renewable solar and wind energy resources.

Set to become one of the largest such facilities in South Africa, the PPR project will assist in reducing South Africa’s

greenhouse emissions, as well as increasing the country’s green ammonia exports by around US$10.5 billion (R189 billion), in the process contributing an estimated R82 billion to GDP.

The abundant solar and wind resources in South Africa, and its strategic positioning in relation to various key markets, create an opportunity for South Africa to capture a significant 5% to 10% of the global green hydrogen market.

Preparing the groundwork

In November 2021, engineering and infrastructure consultancy firm SMEC South Africa was appointed by Prieska Power Reserve to provide project management services to the PPR project. In addition to programme development, scheduling, risk mitigation and scope development services, the SMEC team has also been overseeing progress monitoring and reporting; cost, quality and communication management; procurement management; and project control.

The SMEC team has been instrumental in the PPR project reaching key milestones. These include the completion of technical and pre-feasibility studies for the chemical plant, wind, solar, battery energy storage system and micro-grid control; attaining environmental approvals for certain portions of the site; and the installation of monitoring infrastructure for renewable energy.

It is anticipated that as the project progresses into the next phase, SMEC’s involvement will encompass design facilitation and reviews, cost estimation, and technical assistance through the firm’s various functional groups. These include Roads and Highways, Power and Energy, Construction and Pavements, Management Services, Urban Development, Geotechnical, and Water and Environment.

Roan Ackerman, regional manager and project director, SMEC South Africa

Prieska Power Reserve wind turbine site

Green molecules versus electrons

Roan Ackerman, regional manager and project director at SMEC, says PPR is the first project of its kind in South Africa where a hybrid renewable energy system will be used to produce green molecules (green hydrogen) – an alternative to the current popular green electrons (renewables) generated/used for energy demand.

“We are proud to be involved in a project that not only has the potential to rapidly decarbonise South Africa’s existing industries, but also attract industrial investment to the Northern Cape from across the globe seeking to meet new standards of green power in the production process,” says Ackerman.

Green ammonia production on the PPR project makes use of renewable energy sources through solar power, wind turbines as well as a waste-to-energy plant. Unlike brown and grey ammonia, which is made using fossil fuels as the feedstock, the raw materials for green ammonia are hydrogen obtained through the electrolysis of water (powered by renewable energy sources) and nitrogen (obtained from the air using an air separation unit). Green ammonia is then synthesised from nitrogen and hydrogen via various methods, with the Haber-Bosch process currently being the only method used on a commercial scale – the same method that will be used in the PPR project.

Similar to fossil fuels, ammonia is both a chemical energy carrier, with a high H2 content, and a potential fuel, where energy is released by the breaking of chemical bonds. Ammonia has the advantage of not releasing any carbon emissions if used as a fuel, and its green credentials can be enhanced even further if sustainable energy is used to power the production of ammonia.

Phase 1 production targets

The first phase of the PPR project will target the production of 72 000 tonnes of green ammonia per annum, with a green hydrogen content of 12 900 tonnes via 180 MW of solar power, 130 MW of onshore wind generation, and 129.4 MWh of battery storage. Memoranda of understanding have already been signed with local off-takers.

Production of green ammonia will be increased to over 500 000 tonnes per annum by 2030, with the later phases planning to reach more than 5 GW of renewable generation capacity through wind and solar.

Skills transfer and SMME development

It is anticipated that the PPR project will create over 176 000 job years that will benefit local communities and develop skills for skilled and non-skilled labourers, together with women and youth; it will also result in increased market penetration by female industrialists and female-owned green infrastructure providers.

In addition, it is estimated that the project will result in the upskilling of 16 500 people over a 30-year period, as well as the development of approximately 300 new small businesses, the majority of which will be local and black-owned.

Harnessing the power of the Malawian sun

Operational from Q1 2022, the 20 MW AC Golomoti Solar PV and Battery Energy Storage Project is a groundbreaking development that delivers a green power solution for Malawi.

Co-developed by JCM Power, a Canadian independent power producer, and InfraCo Africa, an investment company of the Private Infrastructure Development Group, the project is believed to be the first utility-scale, grid-connected, hybrid solar and battery energy storage system (BESS) in sub-Saharan Africa.

The project’s success has been made possible due to several partners: USAID, which provided critical development funding; Innovate UK’s Energy Catalyst programme, which provided grant funding for the batteries; and IFU, which provided JCM with debt funding.

Located in Dedza, some 100 km southeast of the country’s capital, Lilongwe, the power facility was built at a cost of around R465 million (inclusive of professional fees and construction costs). This major investment in one of the world’s poorest countries is especially significant given the fact that only about 10% of Malawi’s population has access

to electricity. Malawi currently relies heavily on hydropower, exposing the country to energy security risks during the dry season, as well as extended droughts, making renewable alternatives a highly viable approach.

Zutari was appointed as the engineer for the project. The scope encompassed site identification, concept development, tender development/procurement, preliminary design, and detail design through to project execution. More specific elements comprised the PV plant design and layout, civil works, geotechnical investigation and foundation design, and electrical works. Much of the design and finer details of the project were discussed and resolved online during the learning curve of the 2020 Covid-19 lockdown.

Surrounding villages and a baobab tree

The site location presented several complexities. These included: difficult ground

Completed project as pictured in March 2021. In the centre is the baobab tree that was protected and preserved as part of the final design

conditions that changed with the seasons; a landlocked country, where the procurement of equipment would be expensive and logistically demanding; a complicated site shape, housing a magnificent baobab tree that needed to be preserved; and encroaching village settlements.

Embracing these challenges, the villages and the baobab subsequently became an integral part of the virtual design, which was developed using Zutari’s in-house computational design tool, 7SecondSolar. Thanks to this advanced software platform, it was possible to do multiple design iterations in hours instead of weeks. This enabled Zutari to assist the client with comprehensive design optimisations that provided greater certainty regarding capital expenditure right from the start of the project. That proved highly beneficial, given the constant global fluctuation in PV costs.

Virtual design optimisation continued throughout the development process. Examples include the evaluation of potential PV panel shading by having the panels track the sun’s position. The model also assessed the impact of the baobab tree on potential shading

MW/10 MWh of

in optimising the final PV layout. In the final design, the BESS modules and the tree form the centre around which the surrounding solar array was constructed.

Leading substation design

The Golomoti PV project also used Zutari’s innovative 3D substation design, a field in which the company is a market leader. The 3D design allows a single model to be produced that embodies all the equipment and layout details – available at the click of a button.

Advanced features allow the lightning protection to be viewed in a 3D space to ensure the protection covers all equipment. This 3D facility also increases accuracy and gives design refinement for manufacturing, ensuring all parts fit together, while drawings and bills of quantities can be generated efficiently, quickly and accurately.

Furthermore, civil designs were optimised to reduce costs by designing earthworks and drainage using locally available materials. It was determined that drainage on the site could significantly impact the villages, especially during tropical storm rainfall events. As a proactive measure, the final design catered for this, ensuring water flow is limited and contained to a safe point.

Inverters and transformers

When the client moved towards larger inverters and step-up transformers, Zutari identified the need for an oil management system. It was accomplished using 3D design and included ease of installation, together with the latest technology for an effective oil drainage system something that seemed impossible at the conception stage due to limited space. Noncompliance of proposed equipment to the latest IEC standards was also identified, allowing the client to make better choices. Zutari’s earthing and lightning designs were well received and

subject to an external expert review. Another critical design input was ensuring accessibility to the localised pad-mounted transformer kiosks during Malawi’s rainy season, allowing for maintenance and repair activities. This included draining the road level, which further assisted during heavy downpours.

As the client’s engineer responsible for the final design and delivery, Zutari had to constantly advise on equipment selection and coordination of the various suppliers until the final products were selected. After that, Zutari was responsible for the final system integration into Malawi’s national grid, operated by government-owned utility Escom.

Far-reaching socio-economic benefits Initiatives like the Golomoti Solar PV and Battery Energy Storage Project support the Malawian

government’s drive to reduce poverty and the cost of doing business by revitalising the country’s power supply. It also aligns with Malawi’s strategy of attracting more private investment into the energy sector.

During the project’s construction, more than 550 jobs were created, of which 85% were local jobs for Malawians. Committed to having a positive long-term impact, the project – in partnership with the community – has also developed a Social and Economic Development Plan focusing on woman empowerment, health and sanitation, and subsistence-based sustainable livelihoods.

Overall, the project is a prime example of human-centred, planet-minded design. The result is a best-in-class solution that provides clean power and a future for hardworking rural communities.

24 months to go: if not reset, prepaid meters will stop working

Implications for South Africa

By Kirsten Kelly

Put in layman’s terms, current prepaid metering software that is used by utilities around the world will expire after 24 November 2024. Prepaid meters must be reset and software updated, or consumers will not be able to recharge meters with new tokens and will not have a gas, power or water supply,” says Dr Silas Mulaudzi, specialist: Sustainable Energy, Salga.

Terminology – STS and TID explained

There are approximately 70 million standard transfer specification (STS) prepaid meters in over 40 countries, used by more than 500 utilities.

Encrypted tokens are used to transfer units purchased on to STS meters. These tokens are encoded with a unique token identifier (TID) that represents the minutes elapsed since the base date of 1 January 1993 and identifies the date and time of the token generation. TIDs comprise 20 digits to prevent tokens from being reused at meters. They utilise STS for carrying information between a pointof-sale and a meter.

The use of STS technology prevents: •fraudulent transfer of credit resulting from hit and miss attempts at entering the correct number

•fraudulent generation of tokens from a stolen vending station

•fraudulent generation of tokens from legitimate vending stations outside of the utility's area

•fraudulent reuse of tokens that have already been used

•tampering of legitimate tokens to change the value.

After the 24 November 2024, all STScompliant meters will stop accepting credit tokens that are calculated on the base date of 1993 and the TID value encoded in the token will be reset back to 0 – unless an intervention takes place.

Extending the current vending and current token’s lifetime beyond 2024 would be increasing a security risk to unacceptably high levels and expose the entire water, electricity and gas industries to huge security threats.

According to Salga, well over 3 million STS meters are managed by municipalities and over 7 million STS meters are managed by Eskom. If this deadline is not met, the consequences will be dire. Consumers will be left without services, municipalities will lose a lot of revenue and there is a high chance that there will be violent community protest, some consumers may even illegally bypass the meters.

Process

To prevent this from happening, all utilities and municipalities are obliged to upgrade their vending systems from STS Edition 1 to the STS Edition 2 specification. “This should be done immediately as once municipalities/ utilities have STS Edition 2, they will not have to reset any new meters that they buy from that point onwards,” states Mulaudzi.

However, every prepaid meter that was bought before the vending software was upgraded to STS Edition 2 must be reset with two key change reset tokens and the base date of 01/01/1993 must be changed to a base date of 01/01/2014, forcing the meters to reset the TID stack memory to 0. These two key change tokens (comprising of 20 digits each) must be entered into every single individual meter.

These meters can be reset by: 1) The consumers when they purchase credit. They must be instructed in clear and simple terms to enter the two key change tokens before entering the newly purchased credit token. They must be informed that the newly purchased credit token will only be accepted by the meter if the two key change tokens are entered first. The tokens will have to be numbered in the sequence they have to be entered. Consumers would need to have access to a help desk to provide a second line

Unless updated and reset, prepaid meters (electricity, water and gas) will not accept new prepaid credit tokens after 24 November 2024.

Dr Silas Mulaudzi, specialist: Sustainable Energy, Salga

of technical support to resolve difficult issues.

2) Key change tokens are issued to a dedicated team of technical staff who then visit the meter to enter the tokens themselves. This option provides a good opportunity to do a meter audit and to restore tampered meters at the same time.

“Whatever the method, municipalities and utilities have to dedicate substantial time, effort and resources. Only a few municipalities have started the process of TID rollover thus far. I have received confirmation from Cape Agulhas Municipality that they have finished resetting all of their prepaid meters.

Dr Beyers Naude Municipality have completed over 90% of their meters and Ba-Phalaborwa Municipality have completed 50% of their meters. This is a great achievement; however, we must remember that the number of prepaid meters per municipality differs substantially – from a few thousand to over 300 000,” explains Mulaudzi.

Salga has established a dashboard where the status of TID rollover meters resets is displayed. The dashboard consists of various parameters on the TID rollover data, such as total number of prepayment meters to be reset, number of

prepayment meters that have been reset per municipality, and outstanding number of prepayment meters.

“Our dashboard indicated that over 600 000 out of 2.4 million meters have been reset thus far. However, not all municipalities have returned their questionnaires and we estimate that in excess of 3 million prepaid meters are owned by municipalities,” says Mulaudzi.

Salga has identified a number of challenges with regard to resetting prepaid meters:

•A few municipalities have not taken part in any of the Salga STS surveys, have not attended any of the information sessions and may not even be aware that these meters must be reset.

•Many municipalities do not have the funding or capacity to reset meters. Salga has asked municipalities to quantify the money needed to reset the meters.

•The actual users (consumers) are not aware that the prepaid meters need to be reset.

•In some instances, municipalities that are outsourcing this function are coming across service providers that cannot reset the meters and are unqualified to do so.

•It is often difficult to access the

prepaid meters, as residents are either not at home or do not want to allow anyone on to the property to update the meter.

Assistance

Salga is conducting information management sessions with municipalities and Eskom to raise awareness over the fact that prepaid meters must be reset. A TID committee has been established – comprising Salga, Eskom, National Treasury, Sanedi, AMEU and the STS Association – to support and assist municipalities through advisory services on the TID rollover meters reset.

“We will also continue to facilitate peer-to-peer learning on various aspects of the TID rollover, including the financial implications for the project and timeframes for rolling out the project,” adds Mulaudzi.

Furthermore, Salga has engaged with the South African Council for Graduates, whereby municipalities can use graduates to reset the meters. These graduates can also be used to collect data on other municipal infrastructure like transformers and substations.

Mulaudzi asks all municipalities that have not started this process to please engage with Salga. “Do not underestimate the magnitude of this operation; so start as soon as possible. There is only a relatively short time left to the 2024 deadline. The average metro has over 330 000 prepaid meters to reset; with the two-year deadline, that equates to 431 meters that have to be reset every day (including weekends and public holidays).”

HN Consulting Engineers celebrates 20 years of excellence in 2022

The foundation for the firm based in KwaZulu-Natal (KZN) was established by two highly experienced engineers, namely Mutshutshu Nxumalo and Brian Henwood –specialising in mechanical and civil engineering, respectively – who embraced the vision of South Africa’s 1994 democratic transition to form their own consulting engineering practice, Henwood and Nxumalo Consulting Engineers, in 2002.

The objective from the onset was to pioneer the adoption of the South African government’s mandate to promote diversity and inclusivity in the built environment professions, with a view to providing sustainable value for clients and communities.

In recent years, the firm’s name subsequently transitioned to become HN Consulting Engineers, as the founders, now retired,

prepared a comprehensive handover strategy. Today, the HN top leadership team is headed by Ntembeko Zifuku as managing director, as well as Pierre Queripel, Zanele Mashinini and Graeme Baker as executive directors, each of whom bring a wealth of experience to the business.

“From the onset, our goal was to build a highly capable firm in a parallel approach that entailed the mentoring and development of inhouse professionals, succession planning and the allied strategy of attracting new talent to support our ongoing diversification into new engineering sectors,” says Nxumalo.

“The HN directors now in charge of the business reflect the commitment by the founders towards transformational excellence and the firm’s BBBEE Level 1 status reflects this. Quality assurance has also been enhanced by ISO 9001 accreditation, and the firm now has a full in-house design capacity,” adds Nxumalo.

Roads, transportation and structural engineering have always been a core part of HN’s business, supporting parallel growth into priority sectors. Over the past 10 years, for example, HN has established a specialist water and sanitation unit that has spearheaded the design and execution of a series of treatment works projects. Currently, HN is busy with three conventional water treatment plants at various

stages of design and construction, working as a subconsultant on a multidisciplinary team.

Building, especially from a structural and electrical engineering perspective, has also been a major growth area, with HN design specialists accredited in terms of the Green Star SA rating system implemented by Green Building Council South Africa. Projects include structural and electrical designs for social infrastructure initiatives such as rural schools, community halls and commercial buildings. Technologies include the application of light steel frame building designs.

Rural roads and poverty alleviation

Historically, HN was a key role player in the African Renaissance Road Upgrading Programme initiated around 2001, primarily focused on rural roads in KZN. In term of this, HN worked with the provincial Department of Transport and other consulting firms to spearhead the Vukuzakhe emerging contractor development initiative. Allied to this, Henwood was instrumental in developing the Zibambele Road Maintenance System as a poverty relief programme.

Similar rural road projects at the time took place in the Free State and Eastern Cape. This experience served as a major catalyst for HN’s growth into the high- and low-volume roads segment.

“HN’s operating philosophy has always been solution orientated, with a key focus on innovation, irrespective of the scale of the project,” says Zifuku. “Alongside our engineering skills, we’ve also recognised the importance of focusing on comprehensive community engagement and facilitation, which has become an integral part of our project preparation and programme management.”

Main Road 577

Past milestone projects include Main Road

Driven by its slogan, ‘Engineering for Life’, HN Consulting has grown to become a respected multidisciplinary consulting engineering practitioner in the design, project management and delivery of world-class infrastructure.

L-R: Ntembeko Zifuku, managing director of HN Consulting, together with executive directors Pierre Queripel, Zanele Mashinini and Graeme Baker

577 in Durban. In a joint venture with Royal HaskoningDHV (RHDHV), HN was appointed by the KZN Department of Transport as the lead consultant to undertake the project management and construction supervision of the Dumisani Makhaye Highway (P577) – a 14 km long urban arterial between KwaMashu and KwaDabeka that has contributed to a dramatic improvement in the local transportation network.

This multifaceted and challenging project ran over a period of some 14 years, following staged budget allocations, and was completed in March 2018 at a construction value of around R1.3 billion. The scope included a viaduct over the Umgeni River, bus rapid transit lanes and stations forming part of eThekwini’s Go!Durban IRPTN (Integrated Rapid Public Transport Network) C3 route, bridge and box culvert construction, stormwater drainage, earthworks, layer works and all aspects of road construction. Traversing the hilly terrain, the P577 intersects with five crossroads with atgrade signalised intersections.

In recognition of their performance, the HN Consulting and RHDHV JV received a Commendation at the 2017 CESA AON Engineering Excellence Awards in the category: Projects with a value greater than R250 million. The project also won a Commendation in the Technical Excellence Category at the 2017 National SAICE Awards.

John Ross Highway

Another landmark project was the upgrading of the John Ross Highway (MR496) between Empangeni and Richards Bay (km 0.0 to km 15.2) in KZN. Here, HN’s scope entailed full consulting engineering and project management services (planning, design and implementation) from inception to close-out. With a construction value of some R1.1 billion, the project duration ran over a period of 10 years and was completed in 2015.

Key phases comprised the upgrading of the MR496 from a two-lane road to a fivelane dual carriageway, including three major bridge structures, two road-over-rail grade separations, 15 box culverts and seven signalised intersections.

Shaka’s Rock Interchange

Current ongoing road projects include HN’s involvement in the upgrading of N2 Section 27 between Ballito (km 64) and Tinley Manor Interchange (km 22.8) north of Durban. This long-term project, with a construction value of approximately R1.67 billion, has a duration of some eight years and an anticipated completion date of June 2024.

The project is being led by the JG Afrika and Nyeleti Consulting JV on behalf of Sanral,

with HN appointed as one of the targeted enterprise partners.

To date, HN has undertaken the initial visual assessments, as well as the concept and preliminary design of the Shaka’s Rock Interchange (geometrics and drainage), pedestrian facilities, as well as associated crossroad and railway bridge extensions.

Looking to the future

In recent years, HN has placed a major focus on investing in the latest 3D engineering software as the industry transitions to the building information modelling (BIM) platform – now universal in the collective architectural, engineering and construction sectors – all of which is now taking place in the cloud.

“Interrogation of final design and build execution – from new construction, quantity surveying and life-cycle cost optimisation standpoints – is now constantly live online within a secure project team environment. Updating multifaceted design schedules that could take days in the past can now be completed within a matter of minutes or hours, significantly enhancing efficiencies,” says Zifuku.

“The world keeps on evolving, driven by new technologies, and the need for climate change adaptation. Building on our past experiences, we’re constantly looking ahead to ensure we remain relevant and part of the future of South African construction. We’re here to make a difference,” Zifuku concludes.

Go! Durban IRPTN, Wyebank BRT Station

A completed section of the Main Road 577 winding through the KwaDabeka valley

Resilient gardens

irrigation system is the most efficient irrigation system, as it waters directly to the root zone.

• When watering, check the weather first. If it looks like rain or is very windy, postpone watering.

Over the past 200 years, human activities – such as the burning of fossil fuels like coal, gas and oil, and the clearing of huge swathes of forests and jungles – have increased the release of greenhouse gases.

These greenhouse gases have led to the accumulation of heat energy, which in turn is causing the temperature of the earth’s surface to increase (climate change).

Although climate change is a natural phenomenon, these warming and cooling cycles usually take hundreds to thousands of years to complete. Anthropogenic effects have accelerated these cycles, impacting the earth’s rainfall and temperatures, and causing the climate to change too fast.

Climate forecasts predict that the world’s average temperature will increase by an estimated 2 ° C over the next century. Plants and animals may not be able to

adapt quickly enough to this rapid change in climate, threatening entire ecosystems.

How to design gardens to withstand climate change

• Zone plants according to their water requirements. Group high and low water users together and water each group separately as per their requirements.

• Rainfall will be less frequent, therefore when rain does occur, make a plan to capture the rain for later use or direct it to areas where it is required.

• Plant indigenous plants that occur naturally in your area. Keep in mind that not all indigenous plants are low water users, so choose your plants wisely.

• Do not water between 6:00 and 18:00, especially between October and February. If you have an irrigation system, set it to water during the cooler times of the day.

• Install an irrigation system that makes more efficient use of water. A drip

• An ideal watering schedule is to water infrequently but deeply. This assists plants in becoming more drought resistant by encouraging deep root growth.

• Make use of screening and windbreaks to reduce evaporation in your garden.

• Improve the fertility of your soil. Soil rich in organic content has a better water-holding capacity and provides more nutrients for plants.

• Mulch all your garden beds. Mulch reduces soil water loss by up to 70%.

• Create shade areas in your garden, plant trees and make use of shade structures such as pergolas.

A landscape adapted to the environment will require less maintenance and fertiliser, as well as reduce the need for pesticides and other chemicals.

BIGEN DELIVERS SAFE, RELIABLE WATER TO PALAPYE

Bigen was appointed as lead engineering, procurement and construction (EPC) designer on the Palapye Water Treatment Works Expansion Project, which expanded the current treatment plant with a capacity of 18 Mℓ/day to 58 Mℓ/day. This will service the area for at least another 20 years.

The contract was awarded in June 2019 with a project duration of 30 months. The letter of acceptance was issued on 28 June 2019 with access to site on 12 July 2019.

Expansion of the current treatment plant

A 48 Mℓ/day plant was constructed in two modules that operate in parallel. The project

was completed within the contract period and within budget, even while experiencing the full impact of the Covid-19 pandemic and its related restrictions.

The new plant processes were carefully developed to follow the same process train and design aspect of the existing 18 Mℓ/day plant to allow operators, familiar with the old plant, the ease of understanding and operation the new plant.

The 48 Mℓ/day plant includes the following process elements:

• inlet works

• flow measurement

• pre-chlorination with chlorine dioxide

• pre-liming

• blending tank

The Palapye Water Treatment Works Expansion Project that expanded the current treatment plant with a capacity of 18 Mℓ/day to 58 Mℓ/day

• coagulant dosing and coagulation

• pulsator clarifiers (two off)

• rapid gravity sand filters (10 off)

• post-disinfection by chlorine dioxide dosing

• modifications to the existing sludge handling facility

• modifications to the washwater recovery facility.

Continuous improvements and alternative construction methods were applied to optimise the design of the treatment plant.

The pulsating clarifier structure was extremely complex, with suspended overflow launders and settling hoppers with submerged concrete inlet channel sections.

Various members were redesigned as precast members and a precast yard was established on- and off-site to construct these members concurrent to the main construction activities. This reduced the construction period significantly and resulted in substantial cost and time savings.

A jointing system using expansion joints, water bars, bandage systems and sealants on all structures was changed to an in-fill strip system, whereby separate panels (walls

Filter and clarifiers

C M Y CM MY CY CMY K

Situated about halfway between Francistown and Gaborone in Botswana, Palapye is one of Africa’s fastest growing villages. This placed excessive pressure on the existing water infrastructure of the village and its surrounding areas. The Palapye Water Treatment Works Expansion Project will assist in meeting water demand for the region.

and floors) were cast and allowed to complete the normal concrete shrinking process, after which the 1 m wide in-fill sections between panels were cast.

This required extensive planning between the contracting and design teams as the waiting period for shrinkage impacted significantly on the construction duration. These design changes proved to be highly successful as the quantities of reinforcing steel were reduced significantly, which resulted in cost and time

savings. The success of this construction method was evident when the various sections of the water-retaining structures underwent watertightness testing without any failures.

As the new plant is located on an area next to the existing plant (with shallow rock), various design-level changes had to be made on the various structures to minimise rock excavation and save time and costs.

The existing sludge lagoons were used for the final dewatering of the sludge. An

recovery

additional 20% hydraulic capacity was provided to enable the treatment plant to operate at an increased capacity of 48 Ml/day when there is peak demand.

The hydraulic head available through the plant was limited, as the new 48 Ml/day plant had to tie in with process infrastructure on the old 18 Ml/day plant. There needed to be careful planning as structures were raised and/or lowered while excavation proceeded to identify rock formations under the various structures. Interconnection to the existing infrastructure also posed a risk, as blasting was not possible close to existing infrastructure that could be damaged as a result. The constant changes to design levels proved to be very successful, as no blasting was required on any of the structure excavations, which resulted in further significant cost and time savings.

The following ancillary infrastructure was also provided:

• construction of a control room with Scada walls, boardroom, offices, carports, ablution

Washwater

and kitchen areas for the operators on the old and the new plant

• Scada integration between the new and old plant

• double- and single-storey accommodation units

• paving areas around operator accommodation units

• fencing of the old and the new plant

• modifications to old plant inlet works to accommodate split flow to both plants.

Automation

The design team engaged with the client operators and process personnel throughout the design and construction stages, and jointly selected reliable mechanical and electrical equipment that is locally available and supported, and known to the maintenance personnel. These included pumps, blowers, actuated valves, control and instrumentation equipment already successfully used on the existing and other plants operated by the Water Utilities Corporation of Botswana.

Mechanical equipment is fully automated (with status feedback) and can be controlled via a Scada system from anywhere in the world. All processes are automatically monitored with online measuring equipment for pH, turbidity, chlorine content and flows. The high level of automation allows for only one operator to monitor and control the entire plant remotely.

A specialist water treatment expert was employed by the design team to provide formal process and operations training during the commissioning period up to handover. The services provided by the designer include assistance during the one-year defects liability period. For this, the designer trained a local citizen employee to assist the operators during the defects period.

A remote link to the plant utilising the Scada system was provided to allow the consultant to operate and control the entire plant remotely from its offices in South Africa. This remote connection will also be used to assist the

Sludge pumps Clarifier

operators in fault-finding and troubleshooting. All data is recorded and available to access for information and compliance monitoring during the period of operation.

Challenges

The first challenge was to achieve a fine balance between complying with the bid specifications and competitive pricing. The EPC contracting approach places a lot of the risk on the contractor, which may lead to increased prices if the risk cannot be brought down to the minimum. To be competitive, it was necessary to complete designs at a level of detail that would eliminate completion and performance risks with associated costs. This was done under extreme time pressure and there was limited deviation from the bid stage design.

With the onset of the Covid-19 pandemic, Botswana’s government instituted travel and other restrictions. This impacted both the movement of key design and construction team personnel, as well as the supply chains for many of the construction inputs.

However, due to the national strategic importance of this project, construction work needed to continue. Once special permission had been granted, the EPC team improvised

Precast clarifiers

its way to creating alternative operating procedures. This included a rapid migration to virtual meetings and supervision inspections, and the use of photography for capturing construction progress.

The EPC team demonstrated its commitment to maintain productivity, as many members were forced to endure long periods away from their families as a precaution and to allow adherence to the travel restrictions.

Conclusion

The Palapye Water Treatment Expansion Project resulted in a secure, reliable and safe supply of water to an additional 500 000 people living in the towns of Palapye and Serowe, but also contributed immensely to the local economy of the region in the form of job creation, skills development and local economic expenditure.

Wherever possible, most materials and resources were locally secured. This included the provision of accommodation, furniture, stationery, security, electrical materials, reinforcing, cement, aggregates, formwork, steel pipes, uPVC pipes, bricks, concrete pipes and general building materials.

Fifteen subcontractors were appointed, of which only four were non-local companies. The professional project team also employed additional services from a locally owned citizen subconsultant for the full duration of the project to assist with quality and project management, especially during the Covid-19 lockdown period.

The expansion of the Morupule Power Station (Botswana’s principal domestic source of electricity, located just outside Palapye) and the establishment of the new Botswana International University of Science and Technology (situated on the Tswapong Hills, south-east of Palapye) resulted in significant expansion of the town of Palapye. This project has therefore made an immense contribution to local industries and mines, thereby improving the overall quality of life.

Bigen was fully engaged in all dry commissioning, wet commissioning, trial operation and training activities. Full commissioning and the production of compliant potable water were achieved on 17 January 2022.

The City of Cape Town’s Bellville Wastewater Treatment Plant (WWTP) is the first South African municipal wastewater facility to meet the requirements for SANS/ISO 50001 ‘Energy management system’ certification by the SABS.

CAPE TREATMENT WORKS LEADS WITH ENERGY-EFFICIENCY GAINS

This recognition affirms the City’s commitment to improving the quality of treated effluent, adopting energy-efficient operations and reducing the impact of climate change by lowering carbon dioxide emissions.

“The City of Cape Town is a beacon for all municipalities to drive quality and to certify their delivery of services against South African and international standards,” says Jodi Scholtz, lead administrator of the SABS.

SANS/ISO 50001 provides a practical way for all organisations to improve energy use through the development and implementation of an energy management system. “Since the plant also has SANS/ISO 9001 certification to validate its quality management, it became easier to facilitate the certification process for their energy management system,” Scholtz explains.

In the past four years, the City has invested more than R179.8 million at the Bellville WWTP, which treats around 44.3 million litres of sewage daily. More recently, two contracts have been approved that will see a further estimated investment of more than R120 million for the last phase of the plant’s diffused aeration upgrade.

So far, the energy-efficiency gains include a more than R1 million annual saving in electricity costs, as well as an approximately 1 000 tonne reduction in carbon dioxide emissions each year. Overall, the energy saved is equivalent to treating 3 000 million litres of wastewater annually.

To obtain SANS/ISO 50001 certification, the Bellville WWTP had to develop an energy baseline, implement performance criteria, procure devices to measure the energy consumption, and then develop an energy policy, as well as an energy management system to ensure efficiency of operations.

Process improvements

Key operational changes to further improve energy efficiency include:

• Constructing three primary settling tanks to reduce the solids loading and the chemical oxygen demand (COD) of the wastewater before it’s treated in the diffused aeration reactors. This will achieve at least a 35% reduction in COD, which means lower airflow is required into the reactors, resulting in reduced energy consumption.

• Replacing ageing blowers with

modern, energy-efficient units. A new air distribution system with fine bubble diffusers in the three reactors will be installed with automated dissolved oxygen control. The reactors will be rebuilt to be able to perform full biological nutrient removal, and the new reactor zone configuration – with larger anaerobic and anoxic zones – will be more energy-efficient. The SABS will conduct surveillance audits at the Belville WWTP over the next two years, as part of the terms and conditions to maintain SABS certification.

Jodi Scholtz, lead administrator of the SABS, and Mike Killick, director: Bulk Services, City of Cape Town Water and Sanitation Directorate, during an official ceremony to mark the handing over of Bellville WWTP’s SANS/ISO 50001 ‘Energy management system’ certificate

A bird’s-eye perspective of the Bellville WWTP

The City is in the process of installing new, energy-efficient, vapour-proof LED lights and LED floodlights at the Bellville WWTP

Securing drinking water for communities

South Africa takes the responsibility of clean water seriously and defines this precious resource through the SANS 241 standard.

But recent tests by experts warn that the delivery of potable water is not equal, and factors such as river and sewage pollution need attention.

By Chetan Mistry

In its new report based on first-round tests, WaterCAN noted a rising presence of bacteria in municipal water sources. Alarmingly, at least one municipality’s contamination levels were high enough that authorities urged residents to boil water before use.

The picture becomes more concerning in rural areas. Though WaterCAN didn’t extensively test rural water sources (this being a focus for a future report), it did spot-check raw water sources such as rivers and dams. Those results are concerning, as at least 76% of the tests indicated high levels of harmful bacteria.

In terms of pollution, mining activities count among the oldest sources of contamination. Even slag heaps meant to contain the pollution still routinely leak chemicals into the environment. Rivers in and around Johannesburg, for example, are now practically off-limits to human usage due to over a century of mining contamination.

Industries also frequently dump chemicals into local water supplies, while South Africa’s abundant agricultural activities send even more chemicals and dangerous mineral concentrations into surrounding ecosystems. Earlier this year, CropLife South Africa warned that the country is sitting on a water pollution

Then there’s sewage. According to a paper by Maxwell Constantine Chando Musingafi, entitled ‘Fresh Water Sources Pollution’, many of South Africa’s sewage treatment facilities don’t sufficiently treat dangerous water, and many sewage plants are partially or entirely out of order. Disasters like the recent KwaZulu-Natal floods worsen the situation, as broken pipelines lead to sewage pouring into nearby rivers and the coast.

How to fix water pollution

The list goes on. But let’s focus on solutions. There is no magic wand, yet focused efforts in specific areas

can turn the tide on local water pollution, as illustrated by the following examples:

• Mines can significantly change run-off pollution by recycling on-site water rather than discharging it.

• Industries of all types can realise considerable cost savings and curb water pollution by enhancing their water management.

• Farms and other agricultural operations can improve water usage and reduce problems through more effective land management and irrigation systems.

• Sewage treatment sites can enhance their performance with new, compact systems and improved data visibility.

Technologies and systems

We can tackle today’s water challenges through various water technologies and systems. For example, proactive mines are using new pumping and membrane systems to clean water for internal uses and nearby mining communities. In turn, industrial sites now increasingly rely on innovative digital water management software that gives them much more control over a crucial operational resource.

Agricultural sites are also starting to deploy improved techniques, such as drip irrigation, to save water and reduce wasteful run-off. More farmers also now focus on creating natural water breaks in their land and improving dam management.

However, sewage treatment has the most exciting prospects: the combination of solutions such as chemical-reducing ozone and UV treatment, anti-clog pumps, integrated aeration, robust data analytics and dashboards are transforming the cost and efficiency of these sites.

Lessons from nature

South Africa has to contend with a range of water challenges, including sporadic rainfall, decades of mining and industrial pollution, poor land management, and ageing sewerage infrastructure. These challenges put our people and society at risk – especially the more vulnerable in rural areas.

But we are not too far up that proverbial creek without a paddle. We have the means to address these problems. If we tackle them systematically through collaboration – with an eye on value, delivery and sustainability – we can change things around and ensure clean water for future generations.

Chetan Mistry, strategy and marketing manager, Xylem Africa

Transmission of recorded data

Keller is one of the few manufacturers of modern measurement solutions that also offers its own cloud and IoT technology. Beyond mobile communications technologies, Keller measurement systems also make use of:

• LoRaWAN (long-range wide area network) – an energy-saving network communication protocol for wireless applications (in particular IoT).

• KOLIBRI Cloud – measurement data is stored in a database of KOLIBRI Cloud where historical data is available over time, which gives further insight in consumption and leakage.

LoRaWAN

Using a maximum of 50 kbps, LoRaWAN is designed for comparatively simple data, such as measured values from sensors. The technology has a range of several kilometres and can also penetrate buildings. This is the perfect solution for areas that are too big for wired sensors that have very little cellular coverage yet internet

access. A typical LoRaWAN network consists of a sensor, LoRa transmitter and LoRa gateway (receiver).

LoRaWAN transmission has the following features:

• The data is exchanged via gateways (antennas) that are connected to the network server over the internet. The measurement data is forwarded from the network server to the KOLIBRI Cloud or the application accesses the data from the network server. Individual measured values are transmitted at the shortest possible intervals of approximately 10 minutes.

• The transmission normally takes place without confirmation of whether it was successful.

• With LoRaWAN, radio transmission occurs via public networks (often belonging to mobile communications providers), private networks (a city has its own network) or an open network such as The Things Network.

• Transmission distances are up to 15 km or

over, depending on the conditions on-site.

• Operation without a SIM card/transmission device must be registered to a network.

• It is sent via a licence-free radio frequency. Everyone can establish their own radio system.

• There is (still) no global radio network.

KOLIBRI Cloud

The data is transmitted in encrypted form for LoRaWAN and mobile communications, from the measuring point to the cloud. Current cryptographic processes are used here. The encryption can be stronger for mobile communications as a result of the higher data throughput and the choice of encryption types available.

KOLIBRI Cloud by Keller offers simple and convenient access to the measurement data with personal login details and SSL encryption. With the KOLIBRI Cloud web app, data is available without the need to set up and maintain a database.

Measurement data can be displayed in graphic form and the export function allows one to download data as Excel or CSV files. Measuring points are effortlessly and efficiently monitored with the integrated alarm system. For instance, a warning can be triggered via email if there is an increase in the water level or a battery is running low.

The cloud software interface (API) allows measured values from another software system to be called up in a standardised JSON format via HTTPS. This way, the data can be continuously transferred into the company’s own software system, therefore making processes more efficient, which is the goal of digitalisation with IoT. Keller provides software developers with extensive documentation on the API.

A typical Keller LoRaWAN scheme

The Joburg smart city approach

Smart cities have a variety of definitions and interpretations. To the City of Johannesburg (CoJ), a smart city is citizen-centric, innovative and inclusive, where all citizens have access to services and information, which enhances socioeconomic development and service delivery. It is a safe, sustainable, convenient, prosperous and resilient city.

CoJ’s smart city approach seeks to address the legacy of apartheid and underdevelopment of townships by repairing and rebuilding broken parts of the city and laying solid foundations for a smart city that is globally competitive,” explains Lawrence Boya, director: Smart City Programme, CoJ.

The effects of apartheid on Johannesburg

In any city, there is typically the centre – called the central business district (CBD) – which is flanked by different industries. People usually also live within the CBD or close to it.

“With apartheid, black people could not live within the city centre; they had to live further away from the CBD in terms of the Group Areas Act. To this day, there is still a legacy where people travel far distances from their homes (such as from Soweto, Orange Farm, Diepsloot, Ivory Park) to places of work. This

needs to be corrected. We need to bring work and amenities closer to where people live,” says Boya.

He adds that technology is a great enabler in this respect, where people can now access goods and services through online platforms. “Rolling out broadband and Wi-Fi in public spaces is a great equaliser because then people do not have to travel to access goods and services, and can work from their homes. Making CoJ a smart city helps in incrementally chipping away at inequalities created by apartheid.”

A digital environment

Using smart technology and processes can provide better quality and efficient services to the residents, businesses, investors and visitors of CoJ. “Connectivity should be seen as a basic service; however, CoJ cannot be viewed as a smart city if it is not providing water, electricity and waste management to its citizens,” states Boya.

The aim is for CoJ to be connected digitally wall to wall, where Wi-Fi and 5G are available in all public areas and every home can be fibre connected. “People should be able to transact, look for a job, order goods or study online wherever they are, at any time of the day and any day of the week through the city’s digital infrastructure,” he adds.

Fortunately, private companies are installing infrastructure in places like Soweto, making it easier to create a lastmile connection.

A city of convenience

“In a smart city, services and products needed by citizens should be easy to access. We are looking at a 15-minute city, where everything is in close proximity and there is not a constant need to drive everywhere. Children can cycle to schools; people can walk to the shops,” adds Boya. Queues can be eliminated by offering more services online and digitalising all paper-based and manual functions and services. This will further reduce the need to drive or travel long distances to access services and will shorten the associated timeframes.

“Anyone who owns a smartphone should be able to access government services. The Smart City Programme is driving the digitalisation of all municipal departments.

Smart City Programme

“Just after the 2010 [FIFA] World Cup, CoJ created a dedicated Smart City office.

This office shapes the agenda of the City and long-term development strategy in terms of smart cities. We evaluate global trends and find ways to infuse smart city ideas into the CoJ’s plans. We work together with all departments within the municipality to drive a smart city agenda,” explains Boya.

The Joburg Smart City Strategy has eight pillars:

1) Smart citizen

2) Digitally connected and intelligent city

3) Safe city

4) Smart institution

5) Smart governance

6) Sustainable, liveable and resilient city

7) Smart services

8) Digital/smart economy.

Barriers to smart cities

“Besides the obvious need for digital infrastructure, South Africa must have enabling legislation at a national level. We have a Smart Cities Framework that has been developed by CoGTA but we need to legislate smart cities. Smart cities should be part of government’s National Development Plan. Furthermore, South Africa needs its own smart city standards that will serve as a form of standardisation and for benchmarking. We have looked at the global smart city standards and used best practices and global benchmarks to compare our performance, but there are cases where they are not all applicable to South Africa,” says Boya.

ACHIEVEMENTS OF THE SMART CITY PROGRAMME

• The expansion of the City’s broadband network and the rollout of free Wi-Fi hotspots to identified townships, hostels, flats, student villages and old age homes.

• The implementation of public library IT hubs, library e-learning programmes and the Jozi Digital Ambassadors programme that develops skills for the Fourth Industrial Revolution.

• Reducing paperwork and bringing services online via digital platforms such as Zenzele e-Joburg portal, e-patient record (e-Health), e-Billing, rollout of smart electricity meters, introduction of the e-Services portal through Project Tlhabologo, including other online services such as e-Valuations and e-Recruitment.

• To improve safety, an Intelligent Integrated Operations Centre has been developed, and will be expanded to be the hub of all City operations; an intelligent smart traffic system is in place; and the CCTV footprint in the city is being expanded. This integrates all municipal data on a single platform in a bid to improve decision-making on critical service delivery issues, using technology.

• CoJ has held a Smart City Innovation Challenge in collaboration with Wits University’s Tshimologong Digital Innovation Precinct. The aim is to find and develop digital technology solutions that respond to urban and community challenges and then pilot these solutions around the city.

• There are also plans to develop a unified data and information portal. A draft data strategy is being developed and City data portals are under construction.

• Going forward, any social housing must be built with new building considerations such as the installation of alternative energy solutions, rainwater harvesting systems, and/or rooftop gardens. A waste-to-energy plant is under planning for a public-private partnership.

• Using digital geoinformatics for resource and infrastructure inventory, street name provision and street address management, as well as land-use management, zoning and town planning. Other geoinformatics applications used include digital mapping systems for public data provision, healthcare planning and monitoring of public health risks, City service proximity analysis, and transportation planning and service routing.

• The CoJ has also rolled out a number of smart mobility initiatives such as cashless ticketing systems, traffic signal boards, a mobile app and digital route tracking.

CoJ is currently reviewing its policies and by-laws to ensure that they encourage smart city practices everywhere. The municipality is also including smart city KPIs in all its departmental budgets and plans.

“It is also important to mobilise society and include them into the smart city conversation. What is their vision of a smart city? A smart city mindset is important, and we need to include CoJ citizens wherever possible,” concludes Boya.

The efficiency of Terracrete permeable pavers

As a sustainable drainage system, permeable interlocking concrete pavers (PICPs) provide a highly viable alternative for a host of stormwater and erosion control applications.

Acommon practice in Europe for decades, PICP adoption in South Africa was initially sluggish, but has gained significant traction in recent years thanks to the pioneering efforts of early adopters. The latter include Terraforce, a leading precast concrete retaining block wall manufacturer based in the Western Cape with an expanding global licensee network.

Back in 1994, Terraforce obtained the rights to a German PICP product range. Tested by the Institute of Hydraulic Engineering at Karlsruhe University, this system was capable of infiltrating 400 ℓ/sec/ha and was launched locally in cooperation with Dave King of Inca Concrete Cape. Sadly, the venture failed in South Africa, as the system was designed to be installed mechanically, whereas hand packing was still the norm here.

Taking cognisance of this, Terraforce’s research and development (R&D) team set out to find a more practical, homegrown solution, which led to the launch of the Terracrete eco-paver in 1999. Featuring large internal

openings, this product is suitable for installing hard-wearing, permeable eco-surfaces on roadways, parking areas, or for mixeduse installations such as stormwater detention ponds, as well as for general erosion control measures.

A market in transition

Terracrete is now widely accepted as a versatile, costeffective solution to be used in combination with conventional paving systems or as a standalone solution. However, when initially introduced, it still received a cool reception from the market, despite being purpose-designed for local labour and installation practices.

“Even the development of plastic moulds that allowed for production on a small scale with minimal capital outlay did not help much. Finally, during the years 2002 to 2004, specifiers started to accept the concept and sales began to pick up, and today their popularity is widespread thanks to an increasing emphasis on environmental stewardship,” explains Holger Rust, founder and head, Terraforce.

Today, Terracrete is available locally in the Western, Eastern and Northern Cape, KwaZulu-Natal and Gauteng, as well as internationally in Swaziland, Namibia, the UAE, India and Australia.

Early PICP research

Ongoing R&D studies have further bolstered the market growth for PICPs. These include alternative methods for

Double ring infiltrometertestto

creating permeable and efficient drainage/ infiltration in existing paved areas or in new areas paved with asphalt or interlocking clay/ concrete pavers.

In 2007, Rust worked together with Dr Soenke Borgwardt – landscape architect, consulting engineer and leading expert on the subject in Germany – to highlight findings about the best approach using different fill materials. Borgwardt’s key findings about PICP are as follows:

• A high rate of infiltration demands the maximum open surface area possible without compromising stability.

• Infiltration rates are higher with coarse infill – 2-10 mm (ASTM No. 8) or 2-5 mm (ASTM No. 9) – and regular maintenance by vacuum washing the gravel is very feasible in a way that would not be possible with finer infill such as sand. The latter is also prone to clogging.

Grassed Terracrete pavers at Glendirk Estate, Constantia, Cape Town

Ryan Moore conducting a drench test as part of his UCT postgraduate study

Preparing a testing station for the three types of Terracrete block infill typically employed, namely soil, sand or gravel

Drench test with newly laid Terracrete blocks on the bank of the Nahoon River in East London

• This method is very suitable for upgrading drainage of existing areas or new ones where the presence of heavy vehicles or high traffic volumes could compromise conventional permeable paving.

• It represents an important management tool for affordable and sustainable stormwater control.

“The incorporation of drainage lines along edges, around perimeters and at predetermined centres across parking/ storage areas or roadways makes it possible to upgrade existing ones or enhances drainage/infiltration of new installations. This method can also be applied when new service or irrigation lines must cut across existing parking areas while trees are being established at the same time,” Rust expands.

Terracrete PICP systems are ideally suited to this purpose due to their approximately 40% open spacing design. This compares to around 15% for conventional concrete paving blocks incorporating widened joints.

“In addition – and something that is often neglected – wider spacings allow tree roots to breathe, and for the underlying soil to absorb water and nutrients that get washed off the paved areas,” Rust continues.

Testing for permeability

Studies conducted between 2020 and 2022 by two graduate students from the University of Cape Town’s Department of Civil Engineering on the permeability of Terracrete pavers support Terraforce’s earlier research. Ryan Moore completed his research in 2020 and Banele Noqayi completed his in late 2021, both under the tutelage of Professor Neil Armitage. Moor concluded: “Terracrete systems maintain a steady long-term infiltration rate with minimal maintenance required and these pavements can be aesthetically pleasing by increasing the green land on a property.”

The key consideration to achieving this is to ensure that the in situ soil conditions are suitable or adaptable for PICP installations. For example, a clay soil exhibits poor permeability characteristics and therefore needs extra drainage measures.

Noqayi’s conclusions echoed Moore’s, stating that “the infiltration of Terracrete eco pavers is largely dependent on the underlying soil conditions,” reinforcing the need to design and install subsoil drainage layers where soils prove less permeable. He also found that vegetation increases the infiltration rate through the root system of the plants. This was especially the case where the pavers are not filled entirely to the top to leave space for plant growth. However, Rust adds here that this strategy may

not always be acceptable, in which case loose gravel or stone infill is more appropriate, as stated in Moore’s research results.

“As with any engineered system, effective long-term performance is interdependent on professional design, proper choice of materials and aggregates, as well as accurate installation, supervision of the building process and maintenance,” adds Rust.

“Working together with our local and international licensees, we are committed

to further developing the product and its applications to perfect the process, closely liaising with industry experts as we expand the frontiers of PICP locally and globally,” Rust concludes.

Adding water to the three Terracrete infill types to calculate the different infiltration rates they yield

THE BENEFITS OF TERRACRETE PERMEABLE PAVERS

• Promotes reduction of stormwater load into natural discharge channels and into sewage conveyance systems

• Can reduce excessive flooding in urban areas

• Encourages bidirectional flow of water, either into subterranean aquifers or to allow high water tables to release moisture into the atmosphere

• Promotes the establishment of beneficial soil-borne microorganisms that can neutralise harmful contaminants

• Can significantly reduce the effect of heat generating islands in urban areas

• Can be employed to reverse the sealed nature of large expanses of asphalt to create infiltration lines that can also host significant tree cover

Terracrete blocks used adjacent to traditional pavers to help with drainage of more impermeable surfaces

The pros and cons of 3D concrete printing

the global construction industry

typically lagged other sectors in

adoption of new technologies,

By Otto Botha

However, the benefits of this technology must be carefully weighed against the moral and societal obligations of creating and maintaining jobs in the industry. This is particularly important in the context of the South African socio-economic landscape.

Currently, there are two main types of 3D printing, with the first – plastic printing – having already seen relatively wide adoption across various sectors of industry. For example, 3D printing has been used by temporary works companies to print one-to-one scale prototypes of clamps and other components as part of their product development process. The prototypes are then fine-tuned to work with existing equipment before being manufactured out of their normal materials. This process is far quicker and faster than the conventional method of producing and testing prototypes.

The second type of 3D printing is concrete printing, which enables entire structures and buildings to be printed in concrete. This is the far more disruptive type of 3D printing for the construction industry but, as yet, it has seen limited adoption across the globe. Some countries in Europe and Asia have started using it for selected projects, but it is far from taking over entire construction industries.

In South Africa, 3D printing has not seen any uptake by the industry, but local universities, such as the University of Johannesburg, are doing extensive research and testing on the concept. So, while we do possess the capability, it remains within the realm of academia – for now.

Machines vs employment

In the South African environment, 3D concrete printing could be a game changer for low-cost

housing delivery, which has long been plagued by a variety of challenges, including quality and execution issues. 3D printing could –with limited resources and plant and labour requirements – create houses that are 100% built per design and could be constructed quickly and around the clock.

Unfortunately, the impact on labour would be devastating. In South Africa – which is grappling with an unemployment crisis –companies are incentivised to employ an array of skills on any construction site, from general labourers to artisans, to execute a project. 3D printing can essentially replace all these skills with one or two people on-site who would operate the printer.

There are, however, some notable limitations to concrete 3D printing. For example, scalability is limited, in terms of both height and footprint for building construction, and the current costs of equipment and skills to operate a high-tech 3D printer can be prohibitive.

director, WACO Engineering Services

Balanced approach

It is advisable to use this type of technology in a responsible manner that is balanced against the efficiencies and cost savings that it delivers. Ideally, it should be used where it is fit for purpose, such as where the need to rapidly deliver a large volume of safe and secure residential accommodation outweighs the need to create employment. On other projects, construction should continue in the conventional way, with the emphasis on creating jobs.

As it is, industry is still a good number of years away from adopting and implementing 3D concrete printing, and it will certainly not disrupt the old-school way of doing construction within the next three to four years.

However, it is likely to gain more traction within the next 10 years, but the rate of adoption locally will probably be limited unless there is a drastic revival of infrastructure spend in South Africa and even in the rest of Africa.

Otto Botha, managing

While

has

the

3D printing has the potential to be significantly disruptive and could possibly address challenges such as time-consuming labour, material waste, building delays and dangerous operations involving people.

3D-printed concrete accommodation units built in the USA

THE NEED TO ESTABLISH SUSTAINABLE ECONOMIC CORRIDORS

There are multiple drivers of urbanisation because each geography has its own nuances in terms of how people live, work and play. Climate change, for example, plays a big role in cross-border migration, due to drought forcing people out of certain areas and floods and destruction causing people to rethink where they are staying,” comments Lutchman.

“Obviously, there is the economic value of migrating towards urban centres in search of employment. However, that is only happening because we have ignored the rural economies for such a long time. The main focus of transport planning has always been on the existing metropolitan areas,” he argues.

Lutchman points out that strategic planning in effect encourages urbanisation in the sense that informal settlements are allowed to grow uncontrolled, which impacts sustainability in our urban areas. A new way of thinking is therefore required.

“Adequate transport networks, coupled with a robust industrial development plan for these communities, generates employment and significantly improves the quality of life for many. What stands us in good stead is that we have plenty of land still available, albeit having issues of ownership and accessibility. We need to create economies, rather than isolated communities, that,

in turn, seek livelihoods in metropolitan areas,” he explains.

SDGs 9 and 11

This is critical if South Africa is to realise two significant UN Sustainable Development Goals (SDGs), namely SDG 9, which refers to building resilient infrastructure to promote inclusive and sustainable industrialisation and to foster innovation, and SDG 11, which focuses on making cities and human settlements inclusive, safe, resilient and sustainable.

“If we talk about growing unsustainability in communities, transportation is an important enabler, especially if we want our communities to become a lot more stable and improve the quality of life for all,” says Lutchman.

This, in turn, calls for sustained growth in terms of the National Development Plan 2050 to eliminate poverty and reduce inequality. “We appear to be kicking the can down the road while we should be clawing back on already lost time.”

Integrated Urban Development Framework

Sustainability of communities must be aligned with the Integrated

Development Framework (IUDF) to transform and restructure South Africa’s urban spaces, based on creating liveable, safe, resource-efficient cities and towns that are socially integrated, economically inclusive and globally competitive. “I am not convinced that this is happening. I also think the IUDF needs to be revised to cater for more recent complexities,” points out Lutchman.

“We have growing communities living and wanting to make meaningful contributions in a stagnant to declining economy in some urban metropoles. Many of those who come to metros are not aware of the economic issues. We do not create new economies. We talk industrialisation, but little is done about it,” he adds.

“If we start thinking bigger and harder about how to create sustainable communities, and how to make SDG 11 a tangible reality, we can go a long way to mitigate many of the issues we are currently faced with,” Lutchman concludes.

Vishaal Lutchman, MD: Transport, Zutari

Urban

Africa and South Africa are experiencing rapid urbanisation, which is having a major impact on transport planning, says Vishaal Lutchman, MD: Transport at Zutari.

BUILDING PRECAST STADIUMS

By

One of the major benefits of the precast concrete grandstand system is that it is helping to empower emerging contractors. While subcontracting the construction of the precast concrete grandstand to a specialist in the field, emerging contractors are involved in all other aspects.

Among others, this includes the earthworks and site terracing, the installation of the various services and perimeter fencing, and the construction of the buildings and the pitch. There are also many opportunities to train and develop community members located within the construction footprint – the beneficiaries of the final infrastructure.

A current project example is a sports and recreational centre constructed for a municipality in Limpopo. It features a

grandstand equipped to seat 3 500 people and is the largest structure of its kind designed to date by Infinite Consulting Engineers and subsequently erected by specialist precast concrete innovator Corestruc. This stadium features a roof comprising galvanised structural steel elements, fixed to the concrete structure at strategic positions.

Constructing the grandstand using a precast methodology provided an almost 40% reduction in construction costs for the municipality. This was achieved by eliminating elements that include the need to manufacture bespoke shutters, as well as the requirement for a tower crane.

The grandstand was erected in as little as four months. This is opposed to the 10 months it would have taken to build a similar structure using conventional in situ concrete techniques. Material procurement,

such as the special shutters for the seating benches, columns, raker beams, side panels and closures, and establishing the stacking area, alone, would have taken almost four months using cast-in-place methods. It would also have taken three months just to construct the 9 m high-back columns. This includes setting up the shutters and support, as well as the reinforcement and concrete works. Constructing the 20 bottom, middle and top raker beams and the seating using traditional cast-in-place methods would also have been an onerous, seven-monthlong process.

Precast fabrication

Corestruc’s sister entity, Coreslab, commenced manufacturing of the precast concrete elements for the grandstand in midOctober 2021. The manufacture of the 20

The employment of precast concrete technology for the construction of municipal stadium grandstands provides a faster and more cost-effective means of construction compared to more conventional approaches, as underscored by a recent project in Limpopo.

Kobus Kotze* & Willie de Jager**

Using precast concrete techniques significantly lowers the cost of construction

This grandstand is designed to seat 3 500 people

The grandstand was erected in just four months

The grandstand is the most complicated aspect of sports and recreational centre projects

tapered columns, as well as 20 front-end and 20 top raker beams was completed in mid-January 2022. This is in addition to the more than 340 seating benches, 19 back benches, 34 side panels and 76 steps, as well as the structural steel bracing for the structure.

The principal contractor began constructing the foundations and the cast-in-situ bases in mid-October 2021 in preparation for Corestruc to start erecting the structure in January 2022. This preliminary work included excavation, placement of the stabilised fill, and construction of the in situ 10 MPa concrete bases.

Concrete bases

Constructed in sound founding material, the concrete bases for the front raker beams and front columns are 3 200 mm in width and length and 500 mm thick. For the back columns, the concrete bases are 3 900 mm in width and length and 600 mm deep. The chemical anchors that are used to connect the precast concrete columns extend between 300 mm and 400 mm into the concrete bases and have a pull-out resistance of more than 150 kN.

The back columns were braced vertically with structural steel. By bracing the first and second, third and fourth, fifth and sixth, seventh and eighth, and ninth and tenth columns, five frames spaced 5.5 m apart were created. This provided the critical stability that was required at this stage of the erection process, considering the slenderness of the columns.

The top raker beams were then installed in the same way that the front elements were placed. Afterwards, they were braced horizontally in a similar sequence to that used for the back columns.

This was followed by the placement of the seating benches. They were lined up with the raker beams and then grouted into position and, in doing so, formed a single monolithic structure. The process was followed by the installation of the side panels and steps.

Research and development

Infinite Consulting Engineers and Corestruc have been refining and perfecting this modular system adopted on stadium projects since 2016. The focus has been on designing an ‘off-the-shelf system’ that reduces erection time and requires only minor design modifications –if necessary.

This has been achieved by standardising and reducing the number of prestressed precast concrete elements. The use of curved columns and flat surfaces for the rakers, benches and side panels has also facilitated quick and efficient installation.

Infinite Consulting Engineers has also refined the method of connecting the various precast concrete elements over the years. The columns are connected to the in situ bases by components that have been cast into the precast concrete elements and secured using hold-down bolts in the base.

Furthermore, the raker beams, seating benches and side panels are secured with dowels that fit seamlessly into sleeves that have been cast into the various precast concrete elements and into which the grout is then poured. The dowels have also been strategically positioned to facilitate ease of installation.

These and other innovations have ensured that clients derive maximum benefit from the latest advances in precast concrete technology.

*Director, Infinite Consulting Engineers

**Managing Director, Corestruc

Sustainability requires ethical practices

According to surface mining industry association

ASPASA, sustainability is not the exclusive sphere of environmentalists, but rather the whole supply chain within the infrastructure development process, including the quarrying sector. To achieve this requires strict adherence to ethical practices and quality standards that promote local communities and economies.

The latter are among ASPASA’s key objectives in ensuring the longerterm viability of the South African sand and aggregates industry, and to align it with quality labour and social requirements, as well as legal and environmental compliance.

“The building industry can increase its standards by simply dealing with accredited, sustainably operated suppliers of building materials and therefore discredit unethical and illegal suppliers,” says Anthony Bowen, environmental auditor, ASPASA.

Bowen says that key points for industry to adhere to include:

• sustainable and energy-efficient designs

• environmentally friendly practices

• sustainable maintenance practices

• materials produced in a sustainable way

• material quality

• surrounding communities should derive maximum benefit from all building and construction activities

• skills development and job creation should leave a sustainable legacy.

Governmental cooperation

“In addition, role players need to be identified to drive development and act in a leadership role to ensure sustainability,” explains Bowen. “Our first most important role player is our government, focusing on the development of infrastructure, which all needs to be well mapped out and developed into the community in a sustainable manner.

“The government’s duty is to legislate the quarrying industry and create equal opportunity by cutting out illegal mining and preventing imports of low-grade building materials,” Bowen continues.

“We also need to deal with suppliers and contractors that are focused on true sustainability in terms of social, environmental and economic upliftment of the region and the country,” Bowen concludes.

Anthony Bowen, environmental auditor, ASPASA

READYMIX DRIVERS PLAY A CRUCIAL ROLE IN SOUND PRACTICE

Batching, transporting and the placing of concrete form a close triangle of dependence. The rate at which a concreting job can be done depends on the slowest part of this triangle,” explains John Roxburgh, senior lecturer: School of Concrete Technology, Cement & Concrete SA.

“How you batch and prepare fresh concrete will have a direct effect on its transport, and how the concrete is transported will affect the placing and concrete end product,” Roxburgh continues.

An especially important aspect of transporting concrete is to ensure that,

at the time of placement, the concrete has the desired workability for ease of placement and compaction.

Reasons for loss of workability

Roxburgh says there are four main reasons why concrete may lose workability during transport:

• water evaporation from or bleeding out of the fresh concrete

• hydration of the cement causing structural build-sup in the concrete

• the ‘wearing off’ of the admixtures

• the segregation of the components of the fresh concrete.

“Water is the major lubricant in fresh concrete and a rule of thumb is that

COURSES IN 2023

For more information about School of Concrete Technology courses and scheduled dates for 2023, email rennisha.sewnarain@ cemcon-sa.org.za, phone +27 (0)11 315 0300 or visit cemcon-sa.org.za.

the concrete slump is halved for every 10 litres of mixing water lost per cubic metre of concrete. Most water is lost through evaporation into the air and through the hydration of the cement. Hot, dry and windy ambient conditions will speed up the loss of water,” he states.

Cement gel growth

The hydration of the cement with water not only results in loss of the lubricating mixing water, but also results in cement gel growth. The structural build-up of the cement gel in the mix leads to stiffening and loss of workability. Any increase in the temperature of the concrete or local ambient temperature will speed up this process.

“Although admixtures – particularly plasticising and retarding admixtures – are wonderful modern tools used for

Transporting concrete is an often overlooked but critical part of good concrete practice and has a major influence on downstream quality.

John Roxburgh, senior lecturer: School of Concrete Technology, Cement & Concrete SA

workability retention, they also do over time ‘wear off’ due to the growth of the cement gel,” Roxburgh expands.

The relatively gentle motion of wheeled transport aids the segregation of the stone from the mortar in a fresh mix. Coupled to this is the thixotropic nature of concrete, which naturally stiffens when not agitated due to the abovementioned structural build-up of cement gel in the mix and due to the compacting effect of the settlement of the solids in the mixing water.

“A good example of a thixotropic material is tomato sauce, which needs agitation to flow from the bottle,” he explains.

An agitator vehicle

Roxburgh points out that a readymix concrete truck – in reality, an agitator vehicle – is beautifully designed to mitigate most of the causes of loss of workability in fresh concrete. The enclosed drum slows down evaporation and prevents external contamination; white-painted drums also reflect heat away from the concrete. Spinning the drum will help to keep the concrete homogeneous, breaking down any structural build-up and helping to prevent the concrete from stiffening.

Driver training

Roxburgh says it is important for readymix concrete truck drivers to understand the causes of workability loss and the important roles time, heat, water loss and agitation play in the overall performance of the concrete bought to site for placing.

“Training is essential to equip the drivers with this knowledge. The School of Concrete Technology offers a ‘SCT14 Concrete for RMC truck drivers’ course that specifically deals with important considerations as described above,” Roxburgh adds.

Included in the training is:

• a brief overview of concrete, the roles of each of its ingredients, and the importance of maintaining the correct water-to-cement ratio

• demonstrations and explanations of how to assess the strength and workability of the concrete in the truck

• demonstrations and explanations of concrete cohesiveness and bleeding

• an explanation of the delivery note and the legal implications contained therein

• basic health and safety issues.

A building plan for township communities

Construction materials leader AfriSam – in collaboration with its advertising and brand agency, Promise Group, and leading architecture firm BlackStudio – is inspiring modular, low-cost homes that can grow as needed, foster lasting communities and create concrete opportunities. AfriSam’s ‘Plan (a)’ campaign helps people to build their own homes from an architect-approved plan. The modular design allows for the home to be expanded as needs change and financial resources allow.

In the latest campaign, a carefully designed, fit-for-purpose and architect-approved plan for a modular home is being published as a double-page spread in popular community newspapers, with the heading ‘Build this ad’. Readers can also scan the QR code on the plan to download files for council submission.

The social significance of improved home design and quality is hard to overestimate, according to Moremi Mowela, co-founder and architect at BlackStudio. He points out that many township areas are considered as transitory spaces by young people and are still ‘dormitory towns’ serving the large cities.

“This leads to many people leaving townships as soon as they have the means, creating a drain on skills and capital,” says Mowela. “This process can be reversed if those residential spaces can become aspirational, thereby playing a transformational role in shaping behaviour.”

The architect’s plan adds value across a range of aspects from technical issues like foundation structures, to how the spatial design over time would accommodate changing family needs.

A quality investment

The campaign concept was the brainchild of the Promise Group. “There is a lot that can go wrong in a home building project, so our campaign helps readers to avoid these pitfalls. The ability to build according to a plan maximises the long-term fulfilment they can get from their hard-earned investment,” explains Nic Kostouros, integrated creative director at the Promise Group.

Ebeth van den Berg, group marketing manager at AfriSam, adds that the sentiment behind the campaign was very much to ‘pay it forward’ for customers and the South African public.

“We look forward to developing this concept toward creating a hub for this kind of information,” says Van den Berg.

“There is clearly a need for a highly credible platform where key segments of the housing market can be empowered with professional insights and tools,” Van den Berg concludes.

A carefully designed, fit-for-purpose and architect-approved plan for a modular home is being published as a double-page spread in popular community newspapers

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Each 3 m x 3 m jacking culvert weighs approximately 10.5 t

Culvert underpasses promote safe passage

The City of Ekurhuleni, together with the Passenger Rail Agency of South Africa, launched the Tembisa Pedestrian Underpass Bridges Project in April 2022 to enhance safe mobility. This has led to the establishment of user-friendly underpasses at the Thami Mnyele and Golden Gate rail crossings.

The scope of works for the two underpasses entailed the installation of concrete jacking culverts, measuring 3 m x 3 m, which were purpose designed, manufactured and supplied by Rocla. Each culvert weighs approximately 10.5 t.

The project engineers specified that the culverts were to be jacked at a depth of 4 m below an existing rail embankment.

“We at Rocla then set about customising elements of the culvert design to accommodate this,” explains Mohammad Bodhania, civil engineer, Rocla.

Among the major challenges on-site were the soil conditions.

“The jacking walls, with support by 4 x 18 m anchors and piles in the ground, ensured the walls remained in place, while the use of bentonite limited friction during the jacking process,” explains Hendrik Ferreira, construction supervisor at Esor Construction.

Rocla specialises in the manufacture of a wide range of precast concrete products. These include pipes, manholes, concrete poles, wingwall units, sanitation, as well as bespoke designs that provide durable and practical infrastructure solutions.

Mobile asphalt delivery from Brazil

Progressive expansion has seen ongoing global penetration of Ciber's iNOVA product line, which was introduced in 2017 and unveiled recently for the first time to the European market at bauma 2022 in Munich, Germany.

The top-end model, the iNOVA 2000 – along with the other models in the series – has a well-established track record in countries such as Australia and New Zealand, as well as being a market leader in Latin America and Africa.

With a production capacity of up to 200 t/h, the iNOVA 2000 plant consists of two trailermounted mobile units, each designed to be towed by a truck tractor.

In terms of the design, the external pug mill mixer, with a dry homogenisation stage

between the aggregates and additives –together with automatic control of the mixing time – results in a state-of-the-art continuous flow mixer. This provides the necessary robustness and flexibility for the production of any type of asphalt mix and ensures highest quality.

AutoSmart

For full integration and total plant management, the iNOVA 2000’s AutoSmart package establishes instantaneous communication between the metering, drying, filtering and mixing systems. This feature offers many benefits, including less dependence on operator skills, and automates manual processes that are susceptible to errors, such as the measurement of moisture in aggregates, both before and during production.

The plant’s production process is fully automated and features a touchscreen console for entering production data and adjusting

Adaptive, demand-controlled exhaust system

During operation, the exhaust extraction speed automatically adapts to the momentary production requirements, providing a perfect thermal balance in the system. The dryer’s rotation speed also varies automatically, ensuring the ideal thermal exchange between the aggregates and the plant’s thermal system, regardless of the characteristics of the aggregates, which significantly reduces fuel consumption.

For optimum performance, the digital fault diagnosis system monitors all the plant’s motors and draws on online information to ensure that it always operates at maximum efficiency. The result is a consistently high plant utilisation rate.

The iNOVA 2000 consists of only two mobile units, resulting in low transportation and installation costs

Founded in Brazil in 1958, Ciber Equipamentos Rodoviários is a leading pioneer in the development of mobile continuous asphalt mixing plants and has been part of the Wirtgen Group since 1996.

A Ciber iNOVA 2000 continuous mobile asphalt plant set up for on-site production

the flow