IMIESA May 2021

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

INFRASTRUCTURE DEVELOPMENT • SERVICE DELIVERY • ROADS • BUILDING • MAINTENANCE

Top-end wall technology enhances new homes in Thembisa

Environmental Engineering Designing bio-engineered structures

Who’s Who in Concrete

Solutions for infrastructure development

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Renewable Energy

Hybrid models for sustainable power

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INSIDE

VOLUME 46 NO. 05 MAY 2021

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10 www.infrastructurenews.co.za

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

INFRASTRUCTURE DEVELOPMENT • SERVICE DELIVERY • ROADS • BUILDING • MAINTENANCE

Top-end wall technology enhances new homes in Thembisa

Pumps & Valves

Regulars Editor’s comment

3

President’s comment

5

Index to advertisers

56

Cover Story Top-end wall technology enhances new homes in Thembisa

6

Who’s Who in Concrete Environmental Engineering Designing bio-engineered structures

Renewable Energy

Who’s Who in Concrete

Solutions for infrastructure development

Hybrid models for sustainable power

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ON THE COVER Thembisa residents are among the first to benefit from an advanced, lightweight walling technology, which enhances the quality and affordability of residential apartments in a 500unit project in Extension 27. P6

IN THE HOT SEAT PPC has cautioned against the slow pace of infrastructure development, which could result in more job and value losses for companies in the construction and feeder sectors such as cement and concrete.

Njombo Lekula, PPC MD Southern Africa, stresses the need for proactive engagement and urgent implementation.

P9

25

SMART CITIES

WHO’S WHO IN CONCRETE

Remote pump acceptance testing

33

Renewable Energy Developing a hybrid energy model

34

Creating the future of life

36

Information & Communications Technology Sharing the internet with the world

38

Water quality in the concrete mix

10

Updated specifications are needed to meet cement innovation

Real-time decision-making capabilities in construction

40

12

Creative use of precast

14

Smart devices predict unplanned downtime

41

Paving and kerbing at the Mall of Thembisa

15

Custom-made precast specialists provide solutions to industry

17

SA refines precast reservoir construction 18 Concrete pipes for sewerage and water systems

19

16 on Bree Street

20

MAPEI’s concrete additives – the proof is in the mix design

22

Kerb and drainage system integration

42

Valuable systems upgrade for AECI Much Asphalt

43

Environmental Engineering Designing and building bio-engineered structures

23

Socio-economic factors affecting separation-at-source in Drakenstein

Making smart cities inclusive

24

Testing the logic of the bid scoring process

Innovation can improve water security in cities

25

Building Systems Crucial fire standard updated

Water & Wastewater Importance of water conservation in the built environment

26

Water for rural communities

27 28

Pipe Systems Storing, handling and transporting plastic pipe

27

WATER & WASTEWATER

48

Procurement

Smart Cities

Five steps to achieve good water stewardship practices

44

Innovative rehabilitation of a deep gulley 46

Recycling

Africa Round-up Infrastructure news from around the continent

Roads & Bridges

50

52

Vehicles & Equipment Cooperation spurs transition to battery power

53

Speciality dozers for local landfill sites

55

Health & Safety Safety, health and well-being in construction

56

31

44

ENVIRONMENTAL ENGINEERING

The bee’s knees -

pollinator gardens are in Pollinators are essential for providing food on which humans, birds, insects, and animals rely. The latest environmental positive trend in landscaping is ‘pollinator gardens’ - planting a garden that is attractive to a variety of pollinators including birds, wasps, bees, and butterflies. This action supports biodiversity and protects our environment.

1. Choose plants that are attractive to pollinators.

2. Group your pollinator-friendly plants together.

3. Choose plants with a long flowering cycle.

4. Allow your plants to flower.

5. Indigenous flowering plants are great for attracting local biodiversity.

6. Don’t use chemicals in your garden.

7. Provide a ‘bee-friendly’ water source.

8. Include plants that support caterpillars.

9. Colourful and/or scented flowers are usually great for pollinators.

10. Examples of indigenous pollinatorfriendly plants include vygies, sweet thorn, agapanthus, aloes, clivias, ribbon bush, cape honeysuckle, bush willow, and gazanias.

www.randwater.co.za and click on the Water Wise logo FOR FURTHER INFORMATION ON WATER WISE, PLEASE CONTACT US ON: 0860 10 10 60

EDITOR’S COMMENT MANAGING EDITOR Alastair Currie SENIOR JOURNALIST Kirsten Kelly JOURNALIST Nombulelo Manyana HEAD OF DESIGN Beren Bauermeister CHIEF SUB-EDITOR Tristan Snijders CONTRIBUTORS Fidelis Emuze, Hans King, Frank Major, Gundo Maswime, John Smallwood, Bhavna Soni, Hugh Tyrrell, Tijs van den Brink, Liza Volschenk PRODUCTION & CLIENT LIAISON MANAGER Antois-Leigh Nepgen PRODUCTION COORDINATOR Jacqueline Modise GROUP SALES MANAGER Chilomia Van Wijk BOOKKEEPER Tonya Hebenton DISTRIBUTION MANAGER Nomsa Masina DISTRIBUTION COORDINATOR Asha Pursotham SUBSCRIPTIONS subs@3smedia.co.za ___________________________________________________

Working towards positive change

P

reparations are now well under way for South Africa’s upcoming Municipal Elections, which are scheduled to take place on 27 October 2021, Covid-19 permitting. The last Municipal Elections were held in 2016 and since then a lot has changed within the political and economic landscape.

Whatever the outcome, national government has acknowledged that key changes need to be made to rebuild struggling local municipalities since they are key to proactive socio-economic development. Municipalities will also play a crucial role in the implementation of the Infrastructure Fund’s objectives.

Speaking during National Treasury’s Budget Vote debate in May 2021, Minister of Finance Tito Mboweni said decisive action must be taken to correct deficiencies within the local government space. He pointed out that there are currently 163 municipalities in financial distress, a further 40 in a financial and service delivery crisis, while another 102 municipalities have adopted budgets they are unable to fund.

“We can’t speak of economic recovery and prosperity when municipalities, as agents responsible for helping government achieve these objectives, find themselves in a perpetual crisis,” he said.

Key initiatives to correct this include the District Development Model (DDM) being implemented by the Department of Cooperative Governance and Traditional Affairs (Cogta). In support of the DDM, Cogta also recently concluded a partnership with the UN. This Cogta-UN endeavour will initially focus on the three DDM pilot sites, namely the eThekwini, OR Tambo and Waterberg municipalities. Key Cogta-UN initiatives include the opening of Business Solution Centres, among other development priorities.

ADVERTISING SALES KEY ACCOUNT MANAGER Joanne Lawrie Tel: +27 (0)11 233 2600 / +27 (0)82 346 5338 Email: joanne@3smedia.co.za ___________________________________________________

PUBLISHER Jacques Breytenbach 3S Media 46 Milkyway Avenue, Frankenwald, 2090 PO Box 92026, Norwood 2117 Tel: +27 (0)11 233 2600 www.3smedia.co.za ANNUAL SUBSCRIPTION: R600.00 (INCL VAT) ISSN 0257 1978 IMIESA, Inst.MUNIC. ENG. S. AFR. © Copyright 2021. All rights reserved. ___________________________________________________ IMESA CONTACTS HEAD OFFICE: Manager: Ingrid Botton P.O. Box 2190, Westville, 3630 Tel: +27 (0)31 266 3263 Email: admin@imesa.org.za Website: www.imesa.org.za BORDER Secretary: Celeste Vosloo Tel: +27 (0)43 705 2433 Email: celestev@buffalocity.gov.za EASTERN CAPE Secretary: Susan Canestra Tel: +27 (0)41 585 4142 ext. 7 Email: imesaec@imesa.org.za KWAZULU-NATAL Secretary: Ingrid Botton 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

Pockets of excellence and PPPs It’s important to emphasise that there are key municipalities that do perform exceptionally well in terms of service delivery. Therefore, the platform exists to cross-pollenate these skills and for national government to work with the

WESTERN CAPE Secretary: Michelle Ackerman Tel: +27 (0)21 444 7114 Email: imesawc@imesa.org.za FREE STATE & NORTHERN CAPE Secretary: Wilma Van Der Walt Tel: +27 (0)83 457 4362 Email: imesafsnc@imesa.org.za All material herein IMIESA is copyright protected and may not be reproduced either in whole or in part without the prior written permission of the publisher.

The views of the authors do not necessarily reflect those of the Institute of Municipal Engineering of Southern Africa or the publishers. _____________________________________________ Novus Holdings is a Level 2 Broad-Based Black Economic Empowerment (BBBEE) Contributor, with 125% recognised procurement recognition. View our BBBEE scorecard here: https://novus.holdings/sustainability/transformation The ABC logo is a valued stamp of measurement and trust, providing accurate and comparable circulation figures that protect the way advertising is traded.

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construction sector and general industry to find the best solutions.

As the Infrastructure Fund gains traction, there will be major opportunities for publicprivate partnerships (PPPs) and much needed employment. Prime PPP examples include investments in social infrastructure like hospitals, schools, student accommodation, social housing, waste and wastewater treatment works. In addition to improving service delivery, these projects will further help to empower all municipalities.

In total, some R100 billion in Infrastructure Fund seed funding is planned over a 10-year period to help structure blended PPP finance solutions that could result in R1 trillion in investment. A total of R18 billion in seed funding has been allocated by National Treasury over the 2021/22 to 2023/24 period, amounting to R4 billion, R6 billion and R8 billion respectively.

Economic Reconstruction and Recovery Plan These and other investment initiatives support government’s comprehensive Economic Reconstruction and Recovery Plan (ERRP), which incorporates the Presidential Employment Stimulus (PES) programme. A positive development in this area is the New Development Bank’s recent approval of a US$1 billion (R14 billion) Covid-19 Emergency Program Loan to aid South Africa’s economic recovery. This includes the execution of Phase 1 of the PES. The upside going forward is that there’s a positive change in direction emerging, and South Africa remains a preferred destination for foreign direct investment despite recent credit downgrades. South Africa also has the support of the G7 and G20 group countries.

But now we need those quick wins to bridge the gaps, which will hinge on strengthened collaboration between government and industry to achieve common infrastructure goals.

Alastair To our avid readers, check out what we are talking about on our website, Facebook page or follow us on Twitter and have your say.

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In each issue, IMIESA offers advertisers the opportunity to get to the front of the line by placing a company, product or service on the front cover of the journal. Buying this position will afford the advertiser the cover story and maximum exposure. For more information on cover bookings, contact Joanne Lawrie on +27 (0)82 346 5338.

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IMIESA May 2021

3

BIENNIAL PROJECT EXCELLENCE AWARDS

TUESDAY 16TH NOVEMBER 2021

CALL FOR ENTRIES To recognise outstanding achievements in municipal infrastructure, we are calling for entries

Planning and design Construction methods Innovation and originality

that showcase projects that demonstrate the best of civil engineering as a science and how engineering

Meeting social and technical challenges

enhances the lives of the local communities, through excellence in:

Contributing to the well-being of communities

CATEGORIES

1

ENGINEERING EXCELLENCE IN STRUCTURES & CIVILS E.g. Projects demonstrating engineering science, use of alternate materials, innovative construction processes, etc.

2

COMMUNITY UPLIFTMENT & JOB CREATION E.g. Projects demonstrating labour-intensive construction, skills development, community awareness/participation, etc.

3

ENVIRONMENT & CLIMATE CHANGE E.g. Environmental rehabilitation, renewable energy, drought solutions, coastal initiatives for rising sea levels, pollution control, educational/ technical initiatives, etc.

CLOSING DATE FOR SUBMISSIONS 16 JULY 2021

Only projects that have reached practical or substantive completion by 30 June 2021 will be accepted for the Excellence Awards.

Adjudicators reserve the right to reallocate entries in the 3 categories.

ENTRY FORMS AND AWARD CRITERIA Available for download on the website: www.imesa.org.za

IMESA THE INSTITUTE OF MUNICIPAL ENGINEERING OF SOUTHERN AFRICA (IMESA)

QUESTIONS Contact Debbie Anderson on +27 (0)31 266 3263 or email conference@imesa.org.za

PRESIDENT’S COMMENT

IMESA

Keeping pace with urbanisation Across the world, the migration to towns and cities is on the rise and South Africa is no exception. In our case, though, a key challenge is that our informal and formal population influx places further pressure on water and wastewater infrastructure.

O

ur existing water and wastewater infrastructure is already stretched to capacity due to intensive urbanisation, while supply is further constrained by increasing water scarcity resulting from droughts and climate change.

Based on current sur face and groundwater consumption patterns, the Department of Water and Sanitation’s National Water and Sanitation Master Plan (NW&SMP, Volume 1: Call to Action, 2018) predicts that South Africa could experience a 17% deficit by 2030 unless urgent steps are taken.

That translates into a potential demand shortfall of between 2.7 billion m3/a and 3.8 billion m3/a.

The repor t also states that South African municipalities are losing around R9.9 billion in non-revenue water. This is largely due to technical losses caused by pipeline leakages; however, non-payment of water due to illegal connections and faulty metering is among the other key contributing factors.

Another key issue is the relatively low cost of potable water tariffs. This needs to be addressed so that water boards and municipalities have access to greater funding for infrastructure upgrades, maintenance and service delivery.

Changing consumption patterns Wherever possible, we need to create an equitable balance and be more creative when it comes to utilisation. Agriculture,

for example, uses the most water (around 61% of available resources, according to the NW&SMP) and pays one of the lowest tariffs of any industry. There are also concerns about high wastage due to practices like inefficient irrigation. The second largest user is the municipal/ domestic segment, which currently consumes around 27% and yet pays the highest tariffs.

At some point, and for all industries, direct or indirect reuse will become the norm in South Africa, as it is in many other par ts of the world. In diverse countries like Namibia and Singapore, for example, wastewater reuse for potable consumption is an accepted and safe practice. Meanwhile, in South Africa, indirect reuse from sources like groundwater is already a rising trend, especially in drought-stricken regions like the Eastern Cape. Then there are other opportunities like rainwater harvesting and desalination to consider, which will form an important part of future urban water demand and storage models.

South Africa’s population will live in urban centres by 2030. This is expected to climb to some 80% by 2050, at which stage the country’s total population could be as high as 75 million. The main areas of urban concentration are expected to be Gauteng, eThekwini and Cape Town.

From a municipal engineering and management perspective, it’s therefore vital for us to factor these numbers into our current and future planning. Water demand is only going to escalate.

Population growth The reality is that populations keep growing, while finite resources keep diminishing. This viewpoint is well illustrated by the 2020 State of the Social Housing Sector Report, recently released by South Africa’s Social Housing Regulatory Authority.

Some key takeaways include the prediction that approximately 71.3% of

Bhavna Soni, president, IMESA

IMIESA May 2021

5

COVER STORY

Top-end wall technology enhances new homes in Thembisa Thembisa residents are among the first to benefit from an advanced, lightweight walling technology, which enhances the quality and affordability of residential apar tments in a 500-unit project in Extension 27.

T

he four-storey ‘walk-up’ residential buildings in Thembisa are being constructed with the Sanjo Fabtech Sterling lightweight walling system, also used in the building of upmarket apartments and hotels in Sandton. Construction materials leader AfriSam has been working closely with Sanjo Fabtech Sterling to supply a specialised, lightweight concrete mix for the wall cavities.

According to Jonathan Peel, director at Sanjo Fabtech Sterling, the walling system has enabled a fast-tracked and cost-effective project, which also deals with difficult ground conditions. The company is combining sophisticated, lightweight concrete mixes – designed and developed by sister company SanteQ Liteweight Building Technology – with its permanent formwork walling system.

“Most importantly, the quality of the buildings in the Thembisa project exceeds what homeowners expect from a brick and mortar structure,” says Peel. “The system produces a robust structure, where the solid walls offer excellent sound and thermal insulation, as well as fire resistance.”

The lightweight walling system comprises pre-engineered cellulose-fibre cement boards spaced apart by high-impact moulded inserts manufactured from recycled plastic. The

void between the two layers is filled with the specially designed composite of recycled polystyrene, cement and admixtures.

“The cured weight of the walls is between 550 kg and 1 300 kg per cubic metre, depending on whether it is load-bearing or not,” says Victor Bouguenon, director, SanteQ. “This represents a weight reduction of 50% to 75% when compared to traditional masonry materials, offering distinct design and engineering benefits.”

In the Thembisa project, an important benefit was how this technology addressed problematic soil conditions on-site. Situated in a dolomitic zone, normal building would have required over-engineered and costly foundations. Using lightweight walling, however, significantly reduced the load on the foundations, with commensurate cost savings.

Flexibility Peel highlights that the same walling system can be used for both exterior and interior walls, with varying infill densities and wall widths. In this project, the load-bearing walls measured 229 mm in thickness with a 1 250 density infill, while the internal walls were 112 mm thick with a lighter 500 density infill. The infill mixes offer significant weight reductions over conventional concrete.

Thembisa residents are among the first to benefit from an advanced, lightweight walling technology for a 500-unit residential apartment project

6

IMIESA May 2021

Due to the large volumes of lightweight concrete infill required by the project – over 6 000 m3 – AfriSam was requested to supply a readymix solution. According to Luigi van der Made, readymix operations manager, AfriSam, this involves delivering between 48 m3 and 102 m3 a day of SanteQ’s special mix in readymix trucks.

“The polystyrene is added on-site and mixed thoroughly with the screw-type augers in our 6 m3 capacity readymix trucks,” says Van der Made. “The final infill mixture is then pumped into the walls, speeding up the construction process. We are able to deliver the supply from our Olifantsfontein operation, which is only 9 km from the construction site.”

Innovation The high level of innovation in applying this technology meant that close working relationships were essential to success.

AfriSam made its depth of technical concrete expertise available to test and ensure that SanteQ’s mix designs were suited to the readymix application and consistently applied.

The mixing of the recycled polystyrene using readymix trucks was also a novel concept that required an inventive approach with special drum coating and polystyrene dosing equipment.

“Managing the large quantities of polystyrene beads on-site has certainly been a new challenge for everyone,” he says. “These have to be carefully fed into the readymix trucks, while preventing them from escaping and becoming a source of pollution on-site and beyond.”

COVER STORY

A constant supply of high-specification product was ensured through four dedicated AfriSam trucks

The lightweight walling system comprises pre-engineered cellulose-fibre cement boards spaced apart by high-impacted moulded inserts manufactured from recycled plastic

When returning to the AfriSam plant, it is also vital that the polystyrene left in the residual mixture in the drum does not contaminate any of the other concrete mixtures leaving the plant. This requires a fastidious cleaning process, which must be closely managed.

“In line with our sustainability commitment, we have also been able to put in place a Polystyrene is added on-site and mixed thoroughly with the screw-type augers in the readymix trucks

recycling circuit for the polystyrene washed out of our trucks at the plant,” he says. “Once extracted from the residual mix, these beads are rebagged and returned to SanteQ to be recycled.”

Van der Made notes that a constant supply of high-specification product was ensured through four dedicated AfriSam trucks, to keep the project moving along at the expected pace. This had to be done while constantly ensuring the consistency, workability and cost-effectiveness of the infill mixture.

The special lightweight concrete mix – which does not use coarse aggregate – includes a fine and coarse sand component, as well as fly ash with the cement. Chryso Omega 140 AFR ZA, a high-range water-reducing plasticiser, is also included to increase the slump while reducing the water requirement.

He emphasises that SanteQ’s technical use of fly ash in the various lightweight concrete mixes has enhanced quality, lengthened the delays in setting time, and reduced the carbon footprint of the products.

Local empowerment

The void between the two wall layers is filled with the specially designed composite of recycled polystyrene, cement and admixtures

The Thembisa project has also been able to empower emerging local contractors, engage local labour and expose workers to skills and opportunities in the construction sector due to the simple construction method associated with the walling system.

“With the requisite supervision and planning, contractors can use this walling technology to employ people without previous construction experience,” says Peel. “The walling systems are assembled and erected quickly and cleanly on-site, with minimal waste on prefabricated panels.”

The project has also been able to empower emerging local contractors, engage local labour and expose workers to skills and opportunities

Electrical and plumbing services are preinstalled into the space between the fibrecement boards, after which the infill is pumped into place and the joints skimmed.

The uncomplicated design and quality manufacturing ensure that the walls are plumb and ready for painting, with no plastering required.

So solid is the resulting wall that it can carry loads of up to 40 kg per point, using off-theshelf wall plug and screw mechanisms. The surface of the board can be skimmed, tiled or covered with wallpaper, wood panels and other materials.

By facilitating a consistent build quality, the system helps to keep programme timing and budgets predictable and on track, says Peel.

“Our experience indicates a time saving of around 60% over traditional brick and mortar construction. This reduction in construction times in turn decreases the project management and financing costs,” Peel concludes.

www.afrisam.co.za

IMIESA May 2021

7

SURECAST

A high early strength cement, typical applications are precast concrete products, structural reinforced and pre-stressed concrete, masonry products, paving, grouts, and shotcrete.

It is a tried and tested product that has been engineered to achieve consistent and propriate performance.

It is compatible with commercial chemical admixtures and mineral extenders such as GGBS, GGCS and fly ash.

Scan the QR code to visit our website

PPC, Ask for it by name.

ppc.africa | 0800 236 368

HOT SEAT

A time for action PPC has cautioned against the slow pace of infrastructure development, which could result in more job and value losses for companies in the construction and feeder sectors such as cement and concrete.

Njombo Lekula, PPC MD Southern Africa, stresses the need for proactive engagement and urgent implementation.

I

nfrastructure development has been identified as a key pillar for stimulating economic growth and job creation.

However, a pandemic-induced economic depression, along with South Africa’s fiscal constraints, and a lacklustre approach to resolving the infrastructure backlog, threatens to derail the economic recovery promise.

“The social and economic difficulties facing South Africa demand exceptional and accountable leadership from all sectors. We need leaders who are motivated by action rather than talk in tackling increasing joblessness and the country’s stagnant economy,” said Lekula.

Lekula was speaking at the DEVAC Infrasfuture 2021 conference in Cape Town.

The exclusive two-day annual conference brings together public and private sector decisionmakers – including multinational executives,

Njombo Lekula, PPC MD Southern Africa

international investors, African governments and various other institutions – to address challenges facing the African infrastructure sector.

Lekula said the industry noted with great anticipation the government’s commitment to invest in infrastructure development, including the repair and maintenance of existing assets.

Stronger partnerships, pro-growth policies “Notwithstanding government’s leadership role in this aspect, government cannot do it alone. It is time to forge stronger partnerships to resolve funding challenges and other related issues that are delaying the realisation of our economic goals. It is also urgent that we have more agile and pro-growth policies and regulations that will protect our sector from the harmful effects of imports, whilst enabling accelerated growth of SMMEs,” said Lekula.

The cement and concrete industry were already limping along prior to the Covid-19 pandemic due to a torpid economy, weakened construction sector and the unmitigated flood of cheap imports. The industry depends on natural resource inputs – 97% of locallysourced inputs including limestone and ash.

Cement production is capital-intensive and the industry benefits state owned enterprises (SOE) such as Transnet and Eskom in related service provisions.

Cement imports “It is vital that our policymakers and regulators

appreciate the opportunity that is lost to imports. The 1 million tonnes of cement that is imported to South Africa is the equivalent of a fully integrated cement plant – such as PPC’s De Hoek factory in the Western Cape, which employs about 300 people, running at an estimated value of R900 million in annual operational spend. The bulk of that spend would cover workers’ salaries and much needed revenue to SOEs as well as many SMMEs and local service providers,” said Lekula.

“We need a construction industry master plan to grow and protect the local cement industry and other elements of the value chain.

We need movement on the infrastructure build and maintenance programme, and swift action in local content designation for all SOE and government infrastructure projects to sustain and create more jobs in the sector,” added Lekula.

While calling on policymakers to move with speed, PPC has continued to demonstrate confidence in the country’s growth prospects by investing in SMME development, recommissioning mothballed plants and expanding healthcare access to communities in which the company operates.

“We will continue to forge strong partnerships with all stakeholders and communities to improve the quality of life of all South Africans. In this regard it is imperative to explore alternative building ways, that will include and benefit communities in their housing and infrastructure building initiatives,” concluded Lekula.

IMIESA May 2021

9

WHO'S WHO IN CONCRETE

Sea water may be used for concrete, but only when it does not contain steel reinforcement or other embedded metal

As current and future water scarcity intensifies, concrete producers could come under increasing pressure to use alternatives sources to potable water. While that’s a practical solution, testing will be required to ensure it meets quality standards, says John Roxburgh, senior lecturer at Cement and Concrete SA (CCSA).

Water quality in the concrete mix

M

ixing water makes up about 8% of the total mass of concrete.

So, the propor tion of impurities in the mixing water compared to the mass of cement is typically ver y low. For example, 2 000 mg/ℓ of total

John Roxburgh, senior lecturer, Cement and Concrete SA

dissolved solids in water equates to about 400 g of material per cubic metre of concrete, compared with 300 kg to 400 kg of cement.

Most of the time, these impurities have little to no effect on the hardened concrete; however, the limits to the quantities of

TABLE 1 Requirements for preliminary inspection of mixing water

Item Oils/fats Detergents Colour Suspended matter

Odour

Acids Humic matter

10

IMIESA May 2021

Requirement No more than visible traces Any foam should disappear within two minutes Water not recovered from processes in the concrete industry: the colour must be assessed qualitatively as pale yellow or paler Water from processes in the concrete industry (see SANS 51008) Water from other sources: Maximum 4 mℓ sediment Water from processes in the concrete industry: there must be no smell, except the odour allowed for potable water and a slight smell of cement. Where blast furnace slag is present in the water, a slight smell of hydrogen sulfide is acceptable Water from other sources: there must also be no smell, except the odour allowed for potable water. No smell of hydrogen sulfide after addition of hydrochloric acid is acceptable The pH level must be greater than or equal to 4 The colour must be assessed qualitatively as yellowish brown or paler, after addition of NaOH

impurities in the water should always be checked against the requirements of SANS 51008.

In general, water suitability depends on its origin. Viable examples include: - potable water, which is suitable for use in concrete and needs no testing - water recovered from processes in the concrete industr y - water from underground sources - n atural sur face water and industrial wastewater - sea water or brackish water where the concrete formed does not contain steel reinforcement or other embedded metal;

WHO'S WHO IN CONCRETE

TABLE 2 Maximum chloride content of mixing water

End use of concrete Maximum chloride content, mg/ℓ Prestressed concrete or grout 500 Concrete with reinforcement or embedded metal 1 000 Concrete without reinforcement or embedded metal 4 500

for concrete with steel reinforcement, or embedded metal, the permitted total chloride content in the concrete is the determining factor.

Some common substances deleterious to concrete and found in water are chlorides, sulfates, acids, alkalis, humic matter, oil, algae, sugar and detergents. There are many more and SANS 51008 should be consulted.

“Water for use in concrete must conform to the requirements for preliminar y assessment and for chloride, sulfate and alkali contents. The water must also conform to either the chemical requirements for harmful contamination, or the requirements for setting time and compressive strength,” Roxburgh adds (see Tables 1 and 2).

Water for use in concrete must conform to the requirements for preliminary assessment and for chloride, sulfate and alkali contents.”

The sulfate content of the water must not exceed 2 000 mg/ℓ. This limit should always be assessed with regard to sulfate content within the aggregate and cement.

“If alkali-reactive aggregates are expected to be used in the concrete, the water must be tested for its alkali content. If high, the water may be used only if it can be shown that actions have been taken to prevent deleterious alkali-silica reactions,” Roxburgh explains.

Harmful contamination Regarding harmful contamination, qualitative tests for sugars, phosphates, nitrates, lead and zinc must first be carried out. If the qualitative tests are not per formed or show a positive result, either the quantity of the substance concerned must be determined or tests for setting time and compressive strength be per formed.

The initial setting time obtained on specimens made with the unknown water must not be under an hour and not differ by more than 25% from the initial setting time of specimens made with distilled or de-ionised water. The final setting time must not exceed 12 hours and not differ by more than 25% from the final setting

LIKELY CONSEQUENCES OF IMPURITIES • Alteration of setting times • Increase in water demand • Entraining of excessive air • Change in strength gain characteristics • Degradation of the hardened concrete • Corrosion of the reinforcement within the concrete • Staining • Production of efflorescence

time obtained on specimens made with distilled or de-ionised water.

The mean compressive strength at seven days of the concrete, or mortar specimens prepared with the water, must be at least 90% of the mean compressive strength of corresponding specimens prepared with distilled or de-ionised water.

When sampling water, volumes of at least 5 ℓ must be used, taking the possible effects of seasonal fluctuations into consideration. The water must be tested within two weeks of sampling.

SANS 51008 also provides test methods for the tests required, applicable frequencies for testing, and detailed requirements for the use of water recovered from processes in the concrete industr y. For fur ther information, visit www.cemcon-sa.org.za.

Poor-quality water could affect the quality of concrete

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Updated specifications are needed to meet cement innovation

Roelof Jacobs, manager: Integrated Solutions & Innovation, Lafarge South Africa

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South Africa cannot afford to rebuild concrete structures every few years because they were not constructed correctly the first time.

By Kirsten Kelly

oelof Jacobs, head: Technical Sales and Innovation at Lafarge Southern Africa, believes that greater thought needs to be given when specifying cement and concrete products. “Outdated cement and concrete specifications are still used. We still see tenders/specifications requesting outdated cements like PC15, which was produced in the 1980s.”

He adds that if the specifications for cement are correct, there is often a request for as little extension as possible.

“The reality is that there needs to be a fair amount of fly ash or slag to improve the durability of structures. Furthermore, there is a significant environmental advantage to using SCMs (supplementar y cementitious materials). Updated cement and concrete specifications will likely lead to more durable structures that leave a smaller environmental impact.”

Ten to twenty years ago, slag and fly were used to make cement cheaper, but presently this is not always the case due to transport costs. It often costs more to produce cement with a high fly ash content than to produce cement without it. But even with the increased cost, the durability and environmental benefits of using SCMs are significant.

“Fly ash par ticles, for example, are smaller than cement particles, plugging any gaps. Once cement starts to hydrate,

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fly ash starts to hydrate and creates a gel, producing a denser paste matrix.

Therefore, fewer harmful chemicals can penetrate the concrete. Like fly ash, slag can also be used to create a denser matrix, but it is usually not as fine or as readily available as fly ash,” says Jacobs.

Sulf8CEM Sulf8CEM also assists with the durability of concrete structures. As the only registered sulfate-resistant cement in South Africa, Sulf8CEM is an ideal solution in aggressive environments (like sewage plants).

Sulfates are said to ‘attack’ concrete because they can permeate the sur face layers in solution with water, and react with calcium hydroxide and tricalcium aluminate in the cement paste – making it weak and brittle. The cement paste starts to fall away, exposing aggregates As the only registered sulfatethat then also star t to fall away resistant cement in the country, and the concrete structure begins Sulf8CEM is an ideal solution in to deteriorate. aggressive environments like sewage plants Sulf8CEM is a low-heat (LH), Sustainability sulfate-resistant (SR) cement that On the environmental side, Lafarge is is formulated from Portland clinker that launching a new range of eco-cements. meets the C3A requirement and over 36% selected quality siliceous fly ash, as well Lafarge is the first global building as per formance-enhancing additives. It materials company to sign the Unite Nations has been certified to conform to the latest Global Compact’s Business Ambition for applicable South African and European 1.5°C initiative, with a 2030 SBTi-verified standards (SANS 50197-1 and EN 197-1) (Science Based Targets initiative) action for a CEM IV/B-V 42,5N LH SR. plan. Lafarge plans to reach 475 kg net

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industr y need to change and make more conscious decisions to minimise our impact on the environment. South Africa is lagging with regard to carbon reduction initiatives, and we need to look at successes in other countries and implement them here.

There needs to be far more collaboration between industr y players and government in order to achieve success,” says Jacobs.

Jacobs further believes that a mindset shift should also be applied to the construction industr y’s focus on 28-day strengths. “In our industr y, the 28-day strength concept is like a religion. But why, for example, push for a structure to reach 30 MPa in 28 days when the structure only requires the strength after 56 days due to construction plans? By designing a structure to reach 30 MPa in 56 instead of 28 days, one can not only save on costs but also have a greener product – as less cement is used – and there is an opportunity to use cement with higher amounts of SCMs, which typically increases strengths over a longer period of time.”

Skills Concrete technologists are responsible for most concrete designs and quality control in construction. In the past, most companies had these skills in-house; however, they now rely on external consultants. Therefore, there are fewer technical people in the industr y. “We need good concrete technologists and concrete foremen. And while I have been encouraged by a few young concrete specialists I have worked with recently, there are simply not enough of them,” explains Jacobs.

Oris software In another effort to achieve its carbon neutral status in 2050, Lafarge has developed a software program that CO2 per tonne of cementitious material (net CO2t.cem) by 2030 and to be carbon neutral by 2050.

The company focuses on the whole life cycle of its products: from their manufacture, to their placement and the lifespan of the concrete structures they create.

“Society has to have a mindset shift, where higher extended and more activated cements that are ‘greener’ alternatives to traditional cement are more commonly purchased. We as an

focuses on road design and optimisation, taking the life cycle of the project into account. This is because road design has an impact on up to 60% of the cost of a road project and up to 85% of its overall greenhouse gas emissions.

The software helps road professionals to make data-driven decisions by proposing multiple pavement designs and sourcing options. It also calculates the carbon emissions of the construction of the project and through the life of the road.

This was initially an internal Lafarge development, with IBM, but it has been opened to the industr y in a bid to create greater collaboration in reducing carbon emissions.

SONA Like all companies within the construction industr y, there is ver y little insight as to when or how government’s allocated R226.1 billion (mentioned in President Ramaphosa’s State of the Nation Address) will be spent. “As an industr y, we need to be prepared to supply materials and technologies once these projects come online – but we are all in the dark at the moment,” states Jacobs.

He adds that he is, however, encouraged

by Ramaphosa’s emphasis on localisation.

“While Lafarge is a global company, and we have access to world-class innovations and suppor t, we are ver y much a South African company in that we employ South Africans, manufacture locally, understand the South African construction industr y, and have invested into the South African economy.”

Lafarge focuses on the whole life cycle of its products: from their manufacture, to their placement and the lifespan of the concrete structures they create

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The completed Val de Vie Berg River bridge

Creative use of precast Weighing 64 t each, 18 prestressed beams were employed during the construction of the Val de Vie Berg River bridge in the Western Cape, each measuring over 35 m long and 2 m high. Their manufacture required a creative mix design.

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he large volume and tight spacing of the reinforcing steel, coupled with the presence of stressing cables, meant conventional concrete would not suffice and the local Chryso Southern Africa team worked in conjunction with the precast contractor to design, test and submit a selfcompacting concrete mix.

Chryso Premia 310 superplasticiser and Chryso Dem Bio 10 release agent formed part of the solution for the successful casting of these beams and were also used in the project’s large facing panels, coping and culverts.

Once all the beam strands were evenly stressed, readymix concrete was placed and

Close-up view of the precast facing panels and the prestressed beams

16 of the 18 prestressed beams in place between the abutments and central pier

a combination of external and poker vibration was used for compaction. This provided a good surface finish with minimal blow holes.

After pouring, a tarpaulin was placed over the mould and steam was injected under the cover to accelerate hydration. Using this method, a strength of 40 MPa was achieved in 20 hours, enabling the production of one beam a day. The final strength required was 60 MPa, which was achieved within 28 days.

Off-shutter finish Before the casting process, Chryso Retarder paste was applied at the end of each beam shutter and the concrete washed off with water the following day after the shutter was removed. This created a rough, exposed aggregate finish that provided a

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good bonding surface for the assembly of the bridge.

The facing panels were also steamcured and were cast with a glass-smooth finish. They were attached using ‘fingers’, eliminating the use of visual fixing on the front face. Some panels were curved, such as those used for cladding the central viewing cove.

Once all precast beams were in position, five diaphragm transverse beams were cast in situ between the precast beams.

Permanent deck shutters, measuring 1.2 m by 300 mm by 50 mm, closed the remaining gaps between the precast beams, resting on recesses cast into the beams for that purpose.

Readymix concrete using Chryso’s waterreducing plasticiser Chryso Plast Omega 126 was then poured on to the shutters to create the deck.

Paving and kerbing AT THE MALL OF THEMBISA

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estined to become a major commercial hub, Gauteng’s new 44 690 m2 two-level Mall of Thembisa opened in late 2020, with extensive provision made for vehicular and foot traffic. Here, the mall’s design makes extensive use of precast concrete kerbing for the access roads, building perimeters and parking areas. These were manufactured and supplied by Technicrete.

“With a project of this size and the high number of vehicles and people expected to visit the mall, it was essential that the kerbing not only be aesthetically pleasing, and blend in with the design of the mall, but also offer a long lifespan,” says Loftie Eaton, site manager at Labucon, the main contractor for services and earthworks on the project.

Technicrete supplied 10 000 m of its Fig7 1 000 mm kerbs, 10 000 m of Fig 7 330 mm kerbs, 500 m of Fig 8C 1 000 mm kerbs, and 1 100 m of Fig 10 1 000 m kerbs. In addition, 1 700 m of grey Garden kerbs 500x150x75 mm and 12 012 m2 of Double Zig Zag 60 mm grey paving blocks were used for edge restraint on the pathways.

The Fig 8C kerb is a heavy-duty unit particularly suited for commercial developments, while the Fig 7 kerb has a ‘splayed’ profile. The latter is preferred for developments where vehicles may need to ‘bump up’ on to a verge in an emergency. In turn, the Fig 10 kerb is a light- to medium-duty bull-nosed edge restraint normally applied around islands in parking areas.

Comments Arno Smuts, sales consultant, Technicrete: “Double Zig Zag interlocking pavers are ideally suited for shopping centres, as they offer a continuous, hard wearing surface overlay, which makes them an economical and aesthetically appealing choice.”

The Technicrete products selected for the Mall of Thembisa were manufactured locally to the highest specified standard.

I N N O VAT I O N T H AT B U I L D S N AT I O N S

Phone: 0860 LAFARG (523274) | www.lafarge.co.za

IM/02/202

YOUR PRECAST CONCRETE SPECIALIST PRODUCTS Storm Water Electrical Markers Water Reticulation Outdoor & Building Polymer Products Mining Solutions Kerb Inlet & Road Products Custom Products SERVICES Moulds Drawings

It’s always the last piece in a puzzle that goes missing!

That’s ‘cause we’ve got it!

TWINSTAR PRECAST solves those difficult, one-off jobs that make civil engineering & construction challenging.

Address: Unit 21, Hunky Dory Business Park, 9 Goedehoop Avenue (M57), Olifantsfontein

Telephone: (012) 670 9083 E-mail: info@twinstar.co.za

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Custom-made precast specialists provide solutions to industry Founded in 2014, Twinstar Precast specialises in the manufacture of custommade products and oneoff items for construction companies and civil engineering contractors.

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hile these one-off jobs are usually avoided by typical precasters due to their complexity, size and resource-intensive requirements, Twinstar Precast is specially geared to undertake this type of work.

Customised precast products require a lot of effort and time to design and build oneoff moulds. They also disrupt any normal well-oiled production line, and require additional skills and supervision.

Furthermore, Annemerie Coetzee, owneroperator at Twinstar Precast, says that not all building contractors have the necessary expertise, manpower and facilities to manufacture such products on-site. “As a result, it has become our express aim to assist specifying civil engineers and civil engineering contractors with complicated sites and situations where currently available precast concrete products just won’t work.

A unique sales proposition “We strive to be a solutions-driven problemsolver in all aspects of precast concrete.

Twinstar Precast manufactures products ranging in weight from 2 kg up to 6 t, quickly

and affordably. As a result of the complexity of this type of work, we remain the only company in South Africa specialising exclusively in custom-made and one-off precast concrete products,” Coetzee adds.

Some of Twinstar Precast’s biggest achievements are successfully closing old mineshafts with specially designed and manufactured mineshaft slabs – preventing vandalism and illegal mining activities.

The company also designs and manufactures polymer products such as manhole lids and frames as well as stormwater gratings with no metal components. This dissuades criminals from stealing covers for their steel content and reduces the safety risk of open manholes, as well as the financial implications for municipalities and developers. The components can be bought as a loose item, or cast into the required precast concrete slabs.

“Twinstar Precast’s success is owed to our strong relationships within the industry, ranging from civil engineering contractors – our direct customers – to architects and specifying engineers who conceptualise requirements. We have a unique relationship with mainstream precast concrete companies who pass on referrals and use Twinstar to supply certain non-standard products to keep their clients happy,” Coetzee explains.

While the company’s manufacturing facility is situated in the heart of Gauteng, deliveries are made across the country wherever custom precast concrete products are required. Twinstar also offers a service that enables crane-mounted trucks to assist with the placing of slabs during installation.

Twinstar Precast is specially geared to undertake one-off jobs that are commonly avoided by the average precast concrete product supplier

Stormwater grating

Grid inlet slabs

Precast bicycle railings

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SA refines precast reservoir construction Precast concrete has helped to accelerate and mitigate risks on complex civil engineering projects the world over. This includes reservoir projects, where precast construction tends to be more efficient than cast in situ. However, the real innovation lies in the way they are built on-site, says industry specialist Corestruc.

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he typical precast concrete roof structure comprises hollow-core slabs that are placed on precast concrete beams suppor ted by prefabricated columns. The precast concrete columns are connected to the in situ bases via cast-in components (or column shoes).

These are secured to the hold-down bolts in the same manner as a conventional steel structure. Various column base configurations can be implemented to meet project-specific requirements and their designs must consider a minimum safe bearing capacity of 200 kPa at founding level.

Precast concrete reser voir roof structures are up to five times faster

The use of precast concrete technologies provides additional levels of quality assurance

to build than cast-in-place construction processes. The process can also be sped up even further by including prefabricated walls.

These prefabricated reservoir walls consist of precast concrete panels that have been designed to the required thickness. They have been prestressed during manufacturing and include castin sleeves that have been strategically positioned according to the design requirements for post-tensioning on-site.

Wall installation technique The first panel is placed and supported temporarily and anchored by the following precast concrete elements. This approach requires minimal propping and frees up space. The wall foundation, or ring footing, is designed to transfer vertical loads from the wall and roof to the ground. It also translates the shear force in the wall due to water pressure into the ring tension in the foundation. This tension is

countered with adequate rebar cast into the ring footing.

Unbonded cables are then threaded through the sleeves and joints between the panels. They are temporarily sealed with rubber gaskets to enable the low-viscosity grout to flow through all sleeves and joints.

This grout is self-healing and achieves strengths of up to 100 MPa in a short period. It is cooled to ensure flowability and pumped around the circumference of the reservoir in a controlled manner.

After the grout has cured to a strength of 80 MPa, the cables are stressed to their specified yield via special buttress panels that have been equally spaced along the perimeter. The wall is then pinned by casting a 200 mm to 250 mm high reinforced kicker on the wall footing on both sides of the wall panels.

Joints between the panels are then grouted with a high-flow, high-strength grout. This is followed by post-tensioning to create a watertight structure.

A modular precast approach saves time in constructing reservoirs, mitigating the potential risk of project delays and cost overruns

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Concrete pipes for sewerage and water systems Reinforced concrete pipes with highdensity polyethylene (HDPE) lining

Rocla supplies and manufactures a range of sewerage and water systems to municipalities and civil contractors throughout South Africa.

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mong Rocla’s flagship products are reinforced concrete pipes with highdensity polyethylene (HDPE) lining, which offer sewerage projects the same advantages as a conventional concrete pipe or a plastic pipe, in that it maintains its shape under load and is resistant to acid attack. Exposed concrete in the joints of a pipeline needs to be protected against corrosive gases, and Rocla has designed an HDPE capping strip, which is welded over the joint of the pipe after installation.

It is generally 200 mm wide and the same thickness as the lining used in the pipe.

This unique HDPE-lined pipe was recently commissioned for the Polokwane Wastewater Project, and 19 km of HDPE piping was supplied.

Rocla also manufactures reinforced concrete pipes with sacrificial layers. The host pipe may be manufactured from dolomitic aggregate and ordinary Portland cement or siliceous aggregate and ordinary Portland cement. The sacrificial layer may be from

Rocla was also selected to manufacture and supply all the stormwater (spigot and socket) and interlocking pipes for Waterkloof Quarry – an old, 58 ha landmark situated on the Long-term corrosion protection border of Waterkloof Ridge and Monument The 300 mm to 600 mm reinforced concrete Park near Pretoria – which was developed into pipes are manufactured with the Xypex Bio-San a retirement estate. Rocla’s manufacturing C500 admixture. This is a uniquely designed capability helped in meeting the tight deadline admixture for the integral, long-term associated with the quarry development. protection of concrete in harsh For the recent Diepkloof sewer sewerage conditions, which upgrades, 2 715 piping have high levels of H2S that products and associated cause microbial-induced supplies – comprising corrosion in pipelines.

RJ pipes, rubber rings, The protection is for manholes, cover slabs the full wall of the pipe and concrete lids – were and eliminates extra sourced from Rocla joint sealing. due to the quality of its HDPE-lined Without the Xypex Bio-San manufacturing processes manhole sections C500 admixture, the exposed and final product. concrete in joints of a pipeline Accessories for sewerage and needs to be protected against corrosive water projects also include pipes with gases and Rocla recommends joint sealing access holes, bends (Rocla can supply processes to avoid sewer corrosion activity. custom-made bends of up to 30 degrees), spigot and socket pipe systems, manhole Stormwater chambers with HDPE lining, and reducer and Projects such as the Nellmapius Ext 22 cover slabs. low-cost housing contract near Mamelodi The Rocla design, engineering and technical commissioned nearly 3 000 precast steelteam is available for pre-site design, and mesh-reinforced concrete stormwater pipes of on-site application advice when required. various nominal diameters from Rocla, for the This way, Rocla ensures that the appropriate 6 km stormwater pipeline being constructed. solution is selected and installed correctly. dolomitic aggregate and ordinary Portland cement or dolomitic aggregate and calcium aluminate cement.

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16 on Bree Street Renowned as Cape Town’s tallest residential tower, a phenomenal 36-storey building is located on the everpopular Bree Street. Strategically situated in the CBD, it is within walking distance of attractions such as the V&A Waterfront, Cape Quarter and Green Point, with spectacular views of Table Mountain, the Atlantic Ocean and the cityscape itself.

on Bree Street offers a broad range of accommodation, from R1.9 million studio apartments through to premium penthouses valued at R13.9 million. A few of the key features in the building include a swimming pool on the 27th level, a rooftop bar, and a oneof-its-kind electric vehicle charger.

This is a structure of high-quality build, so Sika South Africa was honoured to be appointed as the product supplier for the revamp and protection project. With a limited timeframe provided to complete the task, this project started on 23 October 2019 and was completed by the end of February 2021.

Concor, the main contractor, together with subcontractors Skysite and engineers Aurecon/Ekcon, coordinated efforts to ensure a well-planned and -executed project. Simon Hareb of Skysite played a critical role in the quality control and application of Sikagard-550 W Elastic.

The aim of the main project was to give the building façade a raw concrete look known as off-shutter concrete, which is suited to modern contemporary design, while still providing an aesthetic protective coating for durability purposes. To achieve this, and to ensure the off-shutter remains in good condition year round, a crack-bridging and concrete repair strategy was required, along with structural strengthening.

Crack-bridging To begin with, Sikagard-550 W Primer was applied evenly on to the concrete. After a five-hour drying period, it was followed by an application of Sikagard-550 W Elastic. This process was repeated two to three times, with an eight-hour waiting period between each coat. The project utilised 800 litres of primer and a total of 4 880 litres of Sikagard-550 W Elastic.

In the endeavour for continued perfection, a wide range of RAL colour samples were

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supplied with over 10 RAL colour requests submitted. Finally, with credit to Wayne Smithers, technical manager at Sika, the ideal colours were selected, and the desired finish of the building was achieved.

Concrete repair A range of Sika MonoTop mortars was used to repair damaged concrete, which also served to give the building a refined, new look. This range, based on its application thickness specifications, allowed for strategic application on different areas of the building, both indoors and out. Needing only water to be added prior to use, a benefit of Sika’s mortars is that they are all compatible, thus facilitating the varying circumstances.

Areas that required extensive repairs were treated with Sika MonoTop-615 HB, a high build repair and reprofiling mortar.

It is designed for thick-layer concrete repairs, especially for overhead and vertical applications. Its excellent workability and adjustable consistency make it a product that is very easy to use.

For the minor defects, such as restoring edges and joints, Sika MonoTop-620 was used. Sika MonoTop-610, a bonding primer, was applied for protection against corrosion and, finally, Sikagard-550 W Elastic was overcoated on all the MonoTop products to ensure no future cracks occur.

plates, required recasting with Sika’s highstrength grout, SikaGrout-212. For the actual structural strengthening, Sika CarboDur S-512 carbon fibre plates were bonded on to the external structure using Sikadur-30 epoxy as its structural adhesive. Sika CarboDur S-512 carbon fibre plates are non-corroding and have a tensile strength 10 times that of mild steel, all of which will ensure the building stands the test of time.

Structural strengthening

Key challenges

When an existing concrete structure deteriorates, or alteration to the structure is made, due diligence must be given to structural strengthening. The durability of the building can be better ensured post repair, as was the case on this project. Parts of the building, like the lift shafts and machine base

As with any project, this one was not free of challenges. Two key factors to deal with were the high moisture content, and the Covid19 lockdown delays, implemented in March 2020. However, delay does not equate to denial, so the project was still completed in good time.

Anthony Webster, technical sales consultant, Sika, was responsible for this project and exceeded the call of duty. By communicating constantly with Sika’s clients, and providing regular on-site training, he ensured a high calibre of customer service to back the products.

Sika has more than 100 years of experience on both large and small concrete projects, all over the world. With Sika’s wide range of innovative and job-specific products, and a dedicated team to back them, this project was not too difficult to execute.

This combination of experience, product and support underscores Sika’s expertise as a go-to supplier. The heritage value of this building façade at 16 on Bree Street was retained, and it blends in seamlessly with its surrounds.

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Concrete additives: The proof is in the mix design

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uch like it is at a restaurant or a bakery, where the importance of the recipe cannot be underestimated or tampered with in order to ensure a successful dish or pastry, the concrete mix design is of critical importance in the world of construction.

This step sets the foundation for the concrete work on any project and is imperative that it is done correctly – with all required results and requirements being met. Unlike a chef or a baker – failure is not an option in construction.

High performance As a leading supplier of additives for concrete, Mapei has built a reputation of providing valuable technical assistance and insight into the development of suitable, high-performing concrete mix designs on local and global projects.

“We believe that – by working together with our customers locally, while accessing our international global experience within the Mapei group – we are best equipped to provide optimal support and input to all our customers,” claims Servaas le Roux, product manager: Concrete Admixtures.

“Each site or project presents its own set of variables that need to be accounted for when developing a suitable mix design. Experience and in-depth knowledge are vital assets at the point of development. This, however, is not where it ends,” he continues.

“Once on-site, there are softer variables that can and often do arise, which can impact on the concrete. As such, Mapei sees the project though to the end alongside our customers, to ensure the best results – always,” adds Le Roux.

“The one thing we don’t compromise on is customer service and support; it’s a non-negotiable for Mapei,” he concludes.

INFRASTRUCTURE NEWS

FROM AROUND THE CONTINENT

MOZAMBIQUE Temporary bridges to replace infrastructure destroyed in cyclones

UGANDA Financing agreement for the Kampala-Jinja Expressway Project The African Development Bank and the government of Uganda recently signed a US$229.5 million (R3.22 billion) financing agreement for the first phase of the Kampala-Jinja Expressway Project, which will cut travel time and boost trade along an important artery linking Uganda with its neighbours.

“This is a public-private partnership (PPP) that will reduce travel time from more than three hours to under one hour between Jinja and Kampala along the northern corridor, linking Uganda to neighbours Rwanda, Burundi, the DRC, South Sudan and Kenya,” announced Matia Kasaija, Minister of Finance, Planning and Economic Development, after the signing.

Private sector participation and financing of a key piece of infrastructure in Uganda will yield a significant economic return for the country, with an estimated net revenue of $2.1 billion (R29.4 billion) over the 30-year concession period.

The project comprises the Kampala-Jinja Mainline Expressway and the Kampala Southern Urban Bypass (KSB). The works will be implemented in two sections. Section 1 is an urban expressway including KSB (18 km) and 35 km of the main expressway from Kampala to Namagunga. Section 2 is a rural motorway covering 42 km from Namagunga to Jinja.

The Uganda National Roads Authority is the executing agency and has already commenced the procurement of a private concessionaire on a design-build-finance-operate-transfer basis under the Availability Payment PPP model.

The African Development Bank has finalised the purchase of 26 modular steel bridges to replace infrastructure that was destroyed in weather disasters in Mozambique. The modular bridges are due to be installed in the coming months after the appointment of local contractors. The goal is to restore transport connections to the isolated regions of Manica, Sofala, Nampula and Cabo Delgado. An estimated 500 000 people are expected to benefit from their installation.

With a service lifespan of up to 100 years, the bridges will provide a temporary solution in areas that are vulnerable to extreme weather while the government invests in climate-smart permanent bridges.

The bridges are funded under the Post Cyclone Idai and Kenneth Emergency Recovery and Resilience Programme, which was approved in the wake of these two cyclones that struck Mozambique, Zimbabwe and Malawi in 2019, affecting around three million people across the three countries.

Central Mozambique has been hit by extreme climate events in recent years.

Cyclones Idai and Kenneth passed through the same region of the country in March and April 2019, also affecting neighbouring countries. Disaster struck again with Tropical Storm Chalane in December 2020 and Cyclone Eloise in January 2021.

KENYA Another substation to minimise outages Kenya Power has launched a 33/11 kV substation in Mtondia, Kilifi. The new substation, which cost US$2.326 million (R32.6 million), comprises four distribution lines (feeders). It is one of four substations the power utility is constructing within Kilifi County at a total cost of $11.77 million (R164.87 million) under the Kenya Electricity Modernisation Project (KEMP).

The other substations are Sabaki 33/11 kV, Kaloleni 33/11 kV and Kokotoni 33/11 kV. Bernard Ngugi, managing director and CEO, Kenya Power, says: “Between 2013 and now, Kilifi County has registered a 260% growth in customer numbers – from 51 821 households to the current 186 403 households.

This has seen access improve from 21% to 71%.” Kenya Power is the country’s sole electricity off-taker and currently has a customer base of over eight million.

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SMART CITIES Smar t cities put people and the environment at the hear t of high-tech developments that use data and technology to drive ser vice deliver y and improve quality of life. But to suppor t these efficiencies, smar t cities often put the technology at the centre and want to implement all innovations at once.

By Tijs van den Brink

Making smart cities inclusive

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his comes with high upfront capital investments, typically recovered through higher property values and rentals.

That immediately excludes the bulk of the population from ever being able to afford to live in a smart city. In a country like South Africa, with one of the world’s greatest inequality gaps, everything possible needs to be done to guard against this.

We can make South African cities smarter by following these three steps:

STEP 1: Gather data Data is the foundation. Knowing exactly what is going on within the city and what the implications of those events are helps authorities make better decisions, faster.

Ideally, data should be gathered in (near) real time from a wide range of sources and sensors. Insights should be presented in a way that enables decision-makers to act as events unfold and helps them understand how patterns evolve over time.

That said, accessing accurate, relevant and real-time data is a challenge in South Africa.

When it comes to infrastructure, authorities often don’t know exactly what exists, what state it’s in, or what it’s being used for. For this reason, South African cities must start gathering information to paint a true picture that they can work with.

STEP 2: Experiment rapidly Rapid experimentation is the only cost-

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effective way to quickly learn which technologies work in the local context, prior to larger-scale roll-outs.

To make this happen systemically, clear plans that prioritise what experiments will be conducted in which cities are needed.

This forms a solid business case for both the current setting and how the experiments will be replicated and scaled to future applications. Remember, these experiments can fail. And it’s okay if they do, as long as they’re stopped immediately, and the lessons learnt are shared widely to prevent future misallocations of funding.

An interesting local example of successful experimentation is the Count Dropula smart water meter initiative launched during the peak of Cape Town’s water crisis in 2018.

Developed by a Stellenbosch University associate professor, the meter helped schools to address water leaks rapidly by notifying them immediately of consumption spikes. Once installed at 350 schools, Count Dropula saved almost 550 million litres in 17 months.

This is particularly relevant for a government that is fiscally constrained as it responds to the Covid-19 pandemic. A broad partnership with the private sector, academia and NGOs also allows for more creative and diverse uses of available data.

On a broader scale, it requires connecting urban development with public sector initiatives, like the Presidential Commission for the Fourth Industrial Revolution, Johannesburg’s Tshimologong Precinct, and Ekurhuleni’s Drone Accelerator Programme.

Ultimately, making our cities smarter is a sustainable and impactful way to improve the quality of life within urban areas. Although often associated with wealthy areas, the smart city concept can be applied to lowerincome areas too to unlock the transformative impact that technology can have on people’s lives.

STEP 3: Partner broadly Learning from and partnering with the private sector has additional benefits. A 2018 MGI report found that “more than half of the initial investment that needs to be made [in service and infrastructure systems] by the public sector would generate a positive financial return, which opens the door to partnerships.”

Tijs van den Brink, advisory group director: Digital Services and Smart Asset Management, Royal HaskoningDHV

Innovation can improve water security in cities

A water-wise city is a smar t choice to optimise Africa’s water infrastructure.

T

he impact of smart infrastructure on the water sector has led consulting engineering firm Zutari to develop digital capabilities that embrace the internet of things (IoT) and Industry 4.0.

“We have a lot of experience in working with the latest industrial automation and instrumentation technologies, which we deploy for infrastructure performance improvement and real-time visibility,” says Neeren Govender, client director: Water at Zutari.

Zutari has innovative data-mining tools for advanced analytics to assist clients with strategic decision-making and long-term planning. These include a smart data-mining platform for improved visibility of critical data.

“One challenge is that our clients often do not have access to their own data. Our tools also allow for accurate tracking as well as improved asset performance and efficiency,” adds Govender.

ZUTARI WATER PROJECTS • Through legacy companies such as Africon and Ninham Shand, Zutari has a track record of almost 90 years in the water sector.

to optimise their energy consumption but also to evaluate the feasibility of waste-toenergy projects, where the energy potential of wastewater can be converted into biogas.

While such technology pushes the envelope in the water sector, a major issue confronting South Africa is ageing infrastructure. “Our biggest challenge is the lack of proactive maintenance. This is linked to a lack of finance, which is why we are starting to see alternative finance models for refurbishing and upgrading essential infrastructure, as well as new infrastructure,” notes Govender.

This includes public-private partnerships (PPPs) or blended finance initiatives such as the government’s mooted R100 billion Infrastructure Fund.

Digital twin for water One of the latest innovations from Zutari is applying the operational digital twin concept to water infrastructure. For example, if a water system needs to be improved, the impact of any changes can be visualised in the digital replica to best optimise the process and carry any lessons or insights through to the real world.

Zutari has also developed energy recovery tools that can assist water utilities not only

SMART CITIES

Neeren Govender, client director: Water at Zutari

• This includes the Lesotho Highlands Water Project (LHWP), originally conceived by legacy company Ninham Shand in the 1950s. The firm was involved in the feasibility studies undertaken in the 1970s and in the design and construction of Phase I in the 1980s and 1990s. Zutari is currently involved in the design of the infrastructure for Phase ll of the LHWP, which remains the largest water transfer scheme in Africa.

• Zutari has been involved in various iconic water infrastructure solutions across the continent, including the Berg River Dam, the Lower Thukela Bulk Water Supply Scheme, the Olifants River Water Resources Development Scheme, the Mokolo Crocodile Water Scheme, the Maguga Dam in Eswatini, the Kashimbila Multipurpose Dam and Hydropower Scheme in Nigeria, the Shire River Basin Management Programme in Malawi, the Water Security and Climate Resilience Project in Kenya, and the Nile Basin Initiative – Pilot Application of the Nile Basin Decision Support System.

“We really need to think differently about the future of water. Our goal as Zutari is to co-create a footprint of engineered water solutions that reframe innovation, sustainability and resilience from an African perspective. We cannot adopt solutions from the US or Europe without taking our local context into account. Zutari continues to embrace the spirit of innovation in its role as a thought leader to improve water security across Africa for future generations,” concludes Govender.

IMIESA May 2021

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WATER & WASTEWATER

Importance of water conservation in the built environment FACTS ABOUT WATER WISE • Water Wise is Rand Water’s environmental brand. It is a campaign aimed at increasing awareness of the need to value water and use it wisely.

• The amount of water available for use remains the same and, despite plans to increase storage capacity through the building of new dams or water transfer schemes, predictions are that the demand for water will outstrip supply by 2025.

S

outh Africa is a semi-arid area with an average annual rainfall of 464 mm, making it very susceptible to water scarcity. Over the years, the country has seen a change in rainfall patterns, where some areas experience increased rainfall and others little to no rainfall.

This informs us that water is not an unlimited resource and it should be conserved for sustainability. Here are some water-wise principles that everyone can incorporate in any built environment.

GREEN BUILDINGS: Companies looking at greening their working spaces can do so by incorporating energy saving technologies such as solar panels on parking or building rooftops, or light control to increase the amount of light flowing through a window. Harvested rainwater can be directed into the garden or office landscape. Small gardens (e.g. rooftop gardens, living walls) can be created in and around the buildings to enhance the environment and improve the well-being of employees.

FOR MORE INFORMATION ON HOW TO BECOME WATER WISE, VISIT:

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IMIESA May 2021

• The only answer to this dilemma lies in changing people’s attitude and thus their behaviour to use water more wisely.

• Changing behaviour at this level requires an ongoing effort, and Water Wise aims to spread awareness and constantly reinforce the message.

HOMES: Homeowners can reduce the amount of clean water used in their households by reusing greywater from showers and bathrooms to irrigate their garden.

Rainwater can be harvested for irrigation or other activities that do not require potable water. In addition, the incorporation of flow regulators in taps and shower heads can help reduce total water consumption by 50%.

LANDSCAPERS: During landscape designing, landscapers can hydro-zone their plants according to their watering needs to reduce the needless watering of plants. After planting, mulch (organic or inorganic material) can be used to cover the soil to help preserve the soil moisture. This, in turn, will reduce the amount of irrigation required.

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www.waterwise.co.za/site/home.html

twitter.com/water_wise

waterwise@randwater.co.za

WATER & WASTEWATER

Water for rural communities Thembisile Hani Local Municipality’s new water treatment works (WTW) provides a new lease on life for communities living in nearby villages that include Boekenhouthoek, Mathysenloop, Machipe and Bundu.

P

rior to this, the municipality mainly depended on other water services authorities for their bulk supply. This included about 15 Mℓ/day from City of Tshwane Metropolitan Municipality, 5 Mℓ/day from Dr JS Moroka Local Municipality, and 35 Mℓ/day from Rand Water.

“Considering operational issues, such as pump failures, the supply was very inconsistent, leaving communities without water for extended periods, especially during the warm summer periods,” says Sarel Holtzhausen, executive director of Ceenex. “The situation has also been severely exacerbated by the drought, with water sometimes having to be transported by road tankers to severely affected areas.”

Ceenex was appointed as the specialist subconsultant for the WTW and pump

This is Thembisile Hani Local Municipality’s largest infrastructure project and its first WTW

system design working alongside Monde Consulting Engineers, the lead engineer on this project. The water augmentation scheme is funded by the Municipal Infrastructure Grant and is being implemented in phases.

The municipality is already supplying over half of the total demand of the planned supply zone at 3 Mℓ/day. The tender for the construction of the final units is expected to be awarded shortly.

and super vision of the various construction components of the scheme.

These included the WTW and a new weir and abstraction point on the Moses River with a capacity of 5 Mℓ/day. The new infrastructure replaces an existing weir that was initially used for agricultural operations before it was damaged by floods.

Ceenex also super vised the building of a new 10 Mℓ/day command reser voir and the construction of sections of the 8 km bulk pipeline associated with the scheme.

Resource study Initially, Ceenex was involved in the resource study for the availability of surface water sources within the area, the findings of which were incorporated into the scheme’s master plan.

After the resource study, Ceenex was appointed by the municipality for the design

The project includes a new weir and abstraction point on the Moses River A sub-base section ready to be stabilised with PPC Sureroad cement

WTW process design The WTW incorporates a conventional treatment process to simplify operation and uses a high-pressure pumping system that comprises top-of-the-range variable-speed pumps sourced from a local manufacturer.

In addition, a novel mechanical rapid gravity sand filter was selected for the removal of fine suspended solids. The polishing filter does not require an external control system or electrical supply, with the backwash cycle initiated autonomously and driven entirely by built-in hydraulics.

This limits operator intervention to periodic maintenance inspections. Powdered activated carbon was also incorporated into the treatment process to remove colouring from the water extracted from the Moses River.

IMIESA May 2021

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WATER & WASTEWATER

Site owners need to gather data on catchments upon which the site relies and affects

Five steps to achieve good water stewardship practices The International Water Stewardship Standard guides companies in planning and implementing an effective response to drought and other water-related risks.

improved water per formance on-site and in the broader catchment in five steps.”

STEP 1: Gather data

Site owners need to gather and understand all of the site’s relevant water-related data, such as: • identifying water sources from which the ccording to Fiona Sutton, site draws principal consultant at SRK • l ocations to which the site returns Consulting, the International its discharges Water Stewardship Standard • catchments upon which the site relies was developed by the Alliance for Water (and affects) Stewardship (AWS). “The standard guides • water balance • water quality • water flows • storage volumes • w ater-related costs and revenues.

The adequacy of available water, sanitation and hygiene ser vices (like water and toilet facilities) needs to be considered in order to combat the spread of waterrelated diseases.

Fiona Sutton, principal consultant at “While time-consuming, this SRK Consulting is perhaps the most important

A

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IMIESA May 2021

stage – as it ensures that the site owner’s future decisions are based on accurate information about water use within its site and catchment. This is the foundation to understanding the site’s water-related risks, impacts and oppor tunities,” explains Sutton.

STEP 2: Plan In this step, a company needs to clarify its mission, vision and goals, as well as the people responsible for water stewardship.

There must be repor ting to regulator y agencies and other stakeholders in line with environmental, social and governance (ESG) obligations. The ways that the plan will be measured and monitored, as well as the actions and timeframes to achieve it, and the financial resources to be committed must also be included.

STEP 3: Implement plan STEP 4: Evaluate performance Sutton emphasises that the organisation’s priority should be to ensure that the measures it takes are sustained, and are continually progressing.

WATER & WASTEWATER

“This is where certification against the AWS Standard plays an important role, as it provides a systematic framework to track the progress made towards water security and to correct the course of action where necessary,” she says.

STEP 5: Engage Companies need to communicate and disclose the progress in their water stewardship journey. This requires careful engagement, based on a good understanding of the organisation’s context or setting – so that its actions have the desired impact.

“There is a need to engage with catchment stakeholders in an open and transparent manner – to understand their priorities, share plans and collaborate on solutions,” she says.

“This engagement allows an organisation to improve its broader understanding of its water usage within a catchment, rather than just within its own site or factory limits.”

Mitigate risk Applying the AWS Standard helps address

Catchment-specific risks are influenced by local water resource management and governance effectiveness in dealing with factors such as increasing demand and unpredictability driven by climate variability.”

Certification three types of risk, all of which have financial implications: physical, regulatory and reputational.

“The physical risks are specific to both the company and the catchment. Catchmentspecific risks are influenced by local water resource management and governance effectiveness in dealing with factors such as

The home of Infrastructure development, building, maintenance, service delivery

increasing demand and unpredictability driven by climate variability. They are also affected by local infrastructure adequacy, the amount of pollution being disposed of into water bodies, and the resulting quality of available water,” adds Sutton.

Risks specific to the company can be direct, such as disruptions in site-level operations or supply chains due to water supply issues or poor water quality. They can also be indirect, such as the non-availability of water services to manage auxiliary operations like wastewater disposal through dedicated wastewater networks.

The AWS awards certification to sites that conform to its requirements. This process is facilitated by specially trained practitioners, paving the way for a detailed audit.

Certification of the AWS Standard is available at three levels: Core, Gold and Platinum.

The AWS Standard helps to achieve on-theground results towards water security for the site and its stakeholders.

infrastructure Complete water resource and wastewater management

Promoting integrated resource and waste management

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

The official magazine of the Water Institute of Southern Africa

The official magazine of the Institute of Waste Management of Southern Africa

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UMGENI WATER IS COMMITTED TO IMPROVING QUALITY OF LIFE AND ENHANCING SUSTAINABLE ECONOMIC DEVELOPMENT

U

mgeni Water like everyone else in the world was not spared from the grip of COVID-19. However, the organisation rose above the limitation of the prevailing conditions. Interruption of services was not an option. The crisis is not over yet, but the Board of Umgeni Water can confidently say that there is a battle plan to secure the health of staff, protect lives, keep potable water flowing and safeguard the environment and downstream communities through continued proper operation, maintenance and management of wastewater treatment plants.

In the medium-term, Umgeni Water will continue efforts to expand coverage in KwaZulu-Natal through the provision of services and products to municipalities that are facing service delivery challenges, or when requested by the KwaZulu-Natal Provincial Government and/or the Ministry of Human Settlements, Water and Sanitation to act as implementing agent.

Umgeni Water again illustrated its strong financial resiliency. In the reporting year Group revenue totalled R4.2 billion and a net surplus of R1.3 billion was achieved, partly as a result of cost containment measures through optimisation of water production process and recovery from the drought in the prior year.

UMGENI WATER 2019/20 ANNUAL REPORT RESULTS A total of

cubic metres per annum (89Ml/d).

were created during the year with R11 million paid in wages to local labour.

The organisation has retained its

55%

32 MILLION

OHSAS 18001 accreditation and was duly awarded

ISO 9001:2015 accreditation.

268 TEMPORARY CAPEX PROGRAMME JOBS

of target Water Infrastructure Project milestones were met.

Improving Quality of Life and Enhancing Sustainable Economic Development.

310 Burger Street, Pietermaritzburg, 3201, Republic of South Africa P.O Box 9, Pietermaritzburg, 3200, Republic of South Africa Tel: +27 (33) 341 1111 / Fax +27 (33) 341 1167 / Toll free: 0800 331 820 Email: info@umgeni.co.za Web: www.umgeni.co.za

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© Umgeni Water 2021

Bulk Wastewater treated over this period was

Think Water, think Umgeni Water.

PIPE SYSTEMS

Storing , handling and transporting plastic pipe Members of SAPPMA (Southern African Plastic Pipe Manufacturers Association) go to great lengths to ensure their products are manufactured according to strict quality standards. Thereafter, the way in which these pipes are stored, handled and transported to site is equally important, says Jan Venter, CEO, SAPPMA, who shares some important tips.

P

lastic pipes are durable, despite their lightness.

Although this makes handling the pipes much easier, it could also potentially mean that they are likely to be mistreated. According to Venter, there are certain reasonable precautions that should be taken to ensure this doesn’t happen.

Storing plastic pipes in direct sunlight, for example, should be restricted to a period of six months from their manufacture. It’s also important to ensure that rubber seals are not exposed to direct sunlight during this period.

Flanged pipes should also not be stacked in large piles, especially under warm conditions: the lower pipes in the stack may become distorted with consequent difficulty in jointing. Additionally, pipes of different diameters should not be nested, one inside the other, when stacked.

Supporting and stacking techniques During storage, the way pipes are supported and stacked is equally important. Plastic pipes should be supported evenly over their whole length.

When stacked, pipes of dif ferent diameters and dif ferent thicknesses should ideally be stacked separately; however, if this is not possible, the largest and thickest pipes should be placed at the bottom. Furthermore, pipes should be stacked on a reasonably flat sur face, free from sharp objects, stones or projections likely to deform or damage them.

Handling While plastic pipes are highly durable, they should not be dropped on to a hard sur face or dragged along the ground. In addition, there are seasonal factors to consider.

For instance, the impact resistance of PVC is reduced in cold weather and more care needs to be taken in handling during winter. If the temperature falls below –5°C, special instructions should be requested from the manufacturer.

Transportation

Jan Venter, CEO, SAPPMA

During transportation, the correct loading and offloading practices will ensure that end products arrive in good condition.

When loading socket-end and spigot-end pipes, for example, they should be stacked so that the sockets do not take any load.

Thicker-walled pipes should also be loaded before thinner-walled ones.

Once the pipes are delivered, it is important for the purchaser to carefully

inspect the pipes at the place of deliver y.

The markings of the pipes should be checked to ensure that they correspond to the specifications of the order, and all seal rings are properly in place.

“Plastic pipes should be synonymous with reliability and trust. While SAPPMA regularly conducts audits to confirm the raw materials that have gone into the pipes, and that quality processes were followed during manufacturing, it is impor tant that this same attention to detail and care be extended to the handling and transpor tation of these pipes. The latter should be as reliable as the pipes that our members manufacture,” Venter concludes.

For more information, visit www.sappma.co.za

IMIESA May 2021

31

Joint International Conference with IMESA & IAWEES

(Institute of Municipal Engineering of Southern Africa & International Association of Water, Environment, Energy and Society)

IMESA

SAVE DATE Registration will open 01 June 2021

EVENT: 84TH IMESA Conference in collaboration with IAWEES DATES: 17-19 November 2021 EARLY BIRD RATE

Register & Pay BEFORE 31 August 2021 Member: R4 000 Non-Member: R4 800

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INTERNATIONAL DELEGATES $430

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PUMPS & VALVES

Remote pump acceptance testing

L

ocal pump manufacturer KSB Pumps and Valves has launched an innovative online acceptance test procedure that adds a new level of customer convenience.

“It enables the customer to see a live camera view of the pump in the test facility, as well as the characteristic curve being generated live from readings taken and displayed during testing,” explains Friedrich Görgens, technical manager, KSB, adding KSB’s test centre in Germiston can accommodate pump sets with a drive rating of up to 550 kW, flow rates up to 3 000 m³/h, and discharge pressures up to 60 bar

that acceptance tests and final inspection are an essential proof of compliance to ensure the guaranteed values are met.

In addition to pressure and flow data, the test software records all further performance data required for a measurement to inspection/ testing standard DIN EN ISO 9906, enabling the derivation and assessment of the pump’s efficiency. The additional measurement and recording of bearing temperature and vibration is available. These are displayed live in parallel to the performance and incorporated in the final test report.

“We provide the customer with organisational information, order data sheets and a precise description of the acceptance testing prior to the acceptance test,”

KSB Pumps and Valves recently introduced remote acceptance testing for the live testing of pumps and hydraulics via the internet

Görgens continues. “This includes details on the measuring instruments used, including the corresponding calibration certificates.”

Testing centre Online acceptance testing is available at KSB’s test centre in Germiston, Gauteng, which can accommodate pump sets with a drive rating of up to 550 kW, flow rates up to 3 000 m³/h, and discharge pressures up to 60 bar. String tests with the customer’s original motors, transformers and frequency inverters can also be performed.

IMIESA May 2021

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RENEWABLE ENERGY

Developing a hybrid energy model For all those nations with abundant coal reserves, fossil fuels will remain a key source of electricity. In parallel, though, is the inevitable shift to renewable alternatives that help to reduce our reliance on fossil fuels, says Thinus van As, function manager: Power and Energy, SMEC South Africa.

By Alastair Currie

T

he transition to alternative energy has been on the cards for decades, and it starts with implementable solutions that lower the lethal carbon dioxide emissions that threaten earth’s longer-term sustainability. In the immediate future, examples include the UK’s plan to end the sale of new petrol- and diesel-driven vehicles by 2030.

“It’s a parallel transition to a greener future that holds exciting possibilities for how the power mix will unfold,” says Van As. “At SMEC, we’re working with private and public sector stakeholders to develop practical models,

Droogfontein 2 solar PV array

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IMIESA May 2021

for either end users or independent power producers (IPPs).”

South Africa’s Renewable Energy Independent Power Producers Procurement Programme (REIPPPP) first launched in 2011 (Window 1).

Local and international teams responded with enthusiasm, executing landmark wind, concentrated solar power, and solar photovoltaic (PV) power projects, many of which, at the time, were the largest globally. Examples include the 75 MW Kathu Solar Park in the Northern Cape, and the 138.6 MW Cookhouse Wind Farm in the Eastern Cape. Through successive REIPPPP stages, South Africa has now moved

Thinus van As, function manager: Power and Energy, SMEC South Africa

to the preparation stages for Window 5. Interested bidders can submit bids ahead of the 16 August 2021 deadline set by the Department of Mineral Resources and Energy (DMRE). Allied to this is the DMRE’s Risk Mitigation Independent Power Producer Procurement Programme (RMIPPPP), where the list of preferred bidders was announced in March 2021. The objective of the RMIPPPP is to add 2 000 MW to the national grid by June 2022, taking some of the pressure off Eskom as it restructures and repositions itself.

A mindset shift “There’s been a definite shift in mindset when it comes to renewables since 2011. Then, for example, remote mines that operated off the grid automatically factored in diesel generation

RENEWABLE ENERGY

power as an inevitable running cost,” Van As explains.

“Now that renewable alternatives are far more mature, however, we are receiving growing enquiries about how mines can greater leverage this, from power security, carbon tax requirement and cost-saving perspectives. The same interest equally applies to general industry,” he continues.

“Our services at SMEC include power feasibility studies for clients that help them optimise potential cost savings using renewable energy. Renewable energy is also clearly in increasing demand as a power security backup measure, given the instability of present Eskom supply,” he adds.

SMEC’s involvement on REIPPPP projects to date includes the following: - Kathu Solar PV - Herbert Solar PV - Greefspan Solar PV - Jeffrey’s Bay Wind - Loeriesfontein Wind - Noupoort Wind - Droogfontein 2 PV - De Wildt PV - Zeerust PV - Perdekraal Wind - Kangnas Wind.

Battery projects The rapid pace of batter y technology research and development is making longer-term energy storage and utilisation increasingly viable. Electric car batteries are a case in point.

“Another evolution in thinking is the way large-scale embedded batter y energy storage systems sync with the grid to ensure power stability during peak and offpeak periods,” says Van As. “That includes active power support, frequency response support, and voltage support.”

City of Cape Town The City of Cape Town stands out as one of the early adopters of renewable energy and has earmarked various sites to build PV plants. Typical sizes envisaged range from 5 MW to 10 MW. “To put that in perspective, the city currently uses around 1.7 GW of peak power. But it’s a step in the right direction, especially in working through and refining current and future IPP regulator y frameworks. Smart metering technology must come into play here in maintaining an equitable tariff model,” Van As continues.

For municipalities, there are two main

implementation options available. The first is to go the build, own and operate route, selling renewable energy into the grid at an agreed-upon tariff, plus some wheeling charges. The second option is to lease or sell land to an IPP and then buy power from them.

Rooftop solar Within the energy mix, the lowhanging fruit are the small-scale embedded generators – essentially the growing population of rooftop solar installations across residential, commercial and industrial buildings in South Africa.

“It’s definitely realistic for gigawatts of power to be generated in this way,” he explains. “However, managing and controlling the buying and selling of surplus power via a network of this nature is a complex challenge that still needs to be thought through.

“What is clear is that there will be an evolving model. Here, energy efficiency will be common cause in lowering the carbon footprint via a stepped approach.

The rest will be driven by economics,” Van As concludes.

IMIESA May 2021

35

RENEWABLE ENERGY

NOUPOORT WIND FARM The power generation landscape will change to a multitude of small- to medium-scale renewable energy generation facilities scattered all over the country, providing much-needed regional economic activities

Creating the future of life The energy and transport sectors are currently undergoing their biggest transformation in over a century. Artificial intelligence (AI) is gaining traction while intertwined smart city concepts are being explored and implemented globally. This enormous transformation bears its risks but foremost presents a unique opportunity for a just energy transition (JET). By Frank Major*

S

outh Africa has some of the best solar and wind resources in the world. By transitioning to a world powered by renewable energy, air quality and, therefore, health will improve, while the shift will also create new income opportunities in a dynamic, decentralised and interconnected electricity network. But what does that mean for municipalities?

Currently driven by a few central GWscale power plants, the power generation landscape will change to a multitude of smallto medium-scale renewable energy generation facilities scattered all over the country, providing much-needed regional economic activities. Energy storage ‘behind the meter’ can help municipalities control their energy security while simultaneously strategically strengthening electrical infrastructure bottlenecks. The traditional transmission and distribution infrastructure will transform into multidirectional, interconnected smart grids.

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IMIESA May 2021

Many homes and business will become both producers and consumers (so-called prosumers) and general demand for electricity will increase due to the electrification of the transport and industrial sectors. New electric vehicle charging and green hydrogen (hydrogen produced from renewable sources) infrastructure will be rolled out to power our electromobility, plus the way we produce and process goods. All this will require more renewable energy to be generated and distributed.

Benefits and implications for municipalities Municipalities can derive various new income opportunities from these developments. This could be through direct participation in power generation projects, in the form of publicprivate partnerships, or by providing wheeling power services through the grid. Then there are the tax income gains from enriched economic activity within regions. Either way, municipalities will be key stakeholders in shaping the JET

into a new distributed energy portfolio and infrastructure framework.

Regional power generation and energy storage will also enable municipalities to ensure critical infrastructure service delivery, such as pumping stations for water supply, desalination plants and water treatment works. Smart metering, combined with AI and digitisation, will further assist municipalities to become more effective and efficient in providing energy, water, communication and transport services to their communities.

South Africa’s strategic approach to PrivatePublic Growth Initiatives, as announced in the State of the Nation Address by President Ramaphosa, opens the door for all public and state-owned entities to engage with and implement these energy solutions, helping to build the foundation for the unfolding JET infrastructure vision. *Frank Major is the solutions lead: Sustainable Energy at iX engineers.

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INFORMATION & COMMUNICATIONS TECHNOLOGY

Sharing the internet with the world

Served by its internet subsea cable from Europe, SEACOM has progressively expanded its fibre Is South Africa ready network in South Africa since for 5G? 2009. This includes key routes SB We’re in the initial linking Johannesburg and Cape Town implementation stages. with Kimberley, Bloemfontein and As in the rest of the world, Durban. Alastair Currie speaks to 5G is an essential platform for realising the Fourth Steve Briggs, chief sales and Industrial Revolution. That in marketing officer, about turn has significant geopolitical evolving trends. and economic implications, since no one wants to be left

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IMIESA May 2021

behind in the information management and communications space.

Within South Africa, it’s been widely publicised that the major cellular network providers are carrying out 5G trials. To effectively roll this out will require a costly investment in new infrastructure. According to estimates, this will require an increase in the current base station densification by a factor of five to achieve the same amount of coverage provided by 4G.

INFORMATION & COMMUNICATIONS TECHNOLOGY

My view is that the market has a way to go before the full logistical implications of a 5G roll-out are understood in practice. A prime example is the issue of who owns, controls and manages radio frequency spectrum allocations.

You could use the current spectrum allocated, but that would just increase the need for more base stations. So, you need a different set of spectrum frequencies to make 5G optimal.

Essentially, there’s plenty of spectrum available within designated narrow and broadband spectrums. It comes down to their allocation, and the optimisation of these scarce resources for the greater good of the country and the industry. In other parts of the world, like the UK and USA, for example, there’s a transparent and open market for the buying and selling of spectrum. In South Africa, the regulatory allocation of spectrum is more complex, and is shaped by policy considerations such as improving competition, driving down data prices, and encouraging new entrants.

So, 5G in South Africa is coming, but it will depend on myriad factors that will influence its speed of implementation.

How will 5G developments influence SEACOM’s business model?

5G is all about much larger and faster data capacities. The final signal will be transmitted from a radio tower, but the bulk of the 5G network will depend on high-speed fibre.

This is where SEACOM comes in, since we’re a fixed-line business.

How do we make data more affordable in South Africa?

Prepaid mobile data is the most common way South Africans access the internet.

Due to the way this is priced, however, it makes prepaid mobile far more expensive compared to users on data contracts.

There are a host of factors that influence pricing, including policy and regulation. From a pure economics perspective, though, it’s clear that running communication services via fibre is more cost-effective than transmitting via a multitude of towers. So that should help to bring down the price.

The game changer is getting more fibre out to where it’s really needed, and finding the right access mechanism, which is probably Wi-Fi. This can bring down data costs for the vast majority. A remarkable example is Project Isizwe’s unlimited Wi-Fi for R5.00 a day campaign. Project Isizwe is a SEACOM corporate social investment partner.

There’s no question that Project Isizwe has transformed many lives, rolling out this initiative to urban, peri-urban and remote rural areas. Having uncapped internet access for the whole day for R5.00 makes the impossible

possible. Children can study, the unemployed can search for work, and new online jobs can be created.

Steve Briggs, chief sales and marketing officer, SEACOM

What are the key trends that will shape the ICT sector in 2021?

Addressing inequality in the digital economy is foremost. Another key trend are the measures needed to improve cybersecurity.

At SEACOM, we have a security product set that assists customers in countering cybercrime threats.

We’ve just launched a whole new product suite known as DDoS (Distributed Denial of Service) Mitigation. Massive data scrubbers housed at SEACOM’s network access points in Europe will be able to keep SEACOM customers’ data traffic secure from cyberattacks.

Is the private and public sector in sync when it comes to ICT? To fully leverage the benefits of our digital world, we need to promote more of a free market approach that encourages local and foreign direct investment.

From our side, SEACOM is committed to presenting the best possible value proposition for our customers. From Q3 2021, this will include Point of Presence connections in Port Elizabeth, East London and George, effectively making the digital economy more accessible to the Eastern and Southern Cape.

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INFORMATION & COMMUNICATIONS TECHNOLOGY

Real-time decision-making capabilities in construction Software solutions provider for the construction industr y RIB CCS has launched a cloud-based data warehouse called Connect. Used by RIB CCS’s Candy and BuildSmar t solutions, Connect will allow for online information sharing between multiple stakeholders throughout an organisation.

Joe de Klerk, head of innovation at RIB CCS

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ith Connect, users can access, process, manage and extract intelligence from the RIB CCS suite of products. All estimation, contract, project contract data and financial data is stored in a central place. This allows for users to gain sight of ever y single aspect of their project, providing one source of truth for an organisation. Connect helps to deliver accurate answers to business-critical questions – anywhere, on any device and in real time.

The brainchild behind Connect is RIB CCS’s head of innovation ̶ Joe de Klerk ̶ a former estimator and long-time RIB CCS Candy consultant. These two roles place him in a unique position to understand customer challenges and look for ways to overcome them.

With Connect, users can access, process, manage and extract intelligence from the RIB CCS suite of products

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“While our customers immediately see the value of our estimating solution, Candy, some of the questions they ask got me thinking about how to optimise the data produced by Candy to promote the sharing of information between project sites and offices, and help them streamline operations by enabling real-time decisionmaking,” explains De Klerk.

Instead of waiting until the end of the month to run Candy and BuildSmart and consolidate costs, Connect gives users access to information on a daily basis.

Therefore, any discrepancies are identified early – before they become major, costly issues.

“Many of our companies have operations in different parts of the countr y. With Connect, Candy users at each site can access data anywhere. In this sense, Candy has essentially been transformed into an enterprise system,” notes De Klerk.

As part of its offering, RIB CCS has introduced a business intelligence

We built an application to meet our clients’ reallife needs, rather than something we thought they may need. There is not another core, like-for-like solution that consolidates, draws insights from, and reports on Candy and BuildSmart data like Connect does.”

(BI) tool – Connect BI – which allows for the dashboarding of information and delivers a ‘project on a page’. “Connect BI gives the user a snapshot of a particular project. Furthermore, all projects can then be consolidated to provide a ‘company on a page’ by consolidating all BuildSmart data,” adds De Klerk.

Connect has been launched after a twoyear development process by a talented innovation team within the RIB CCS organisation, around the globe. RIB CCS also consulted its clients regarding the type of functionality that they needed. “We built an application to meet our clients’ real-life needs, rather than something we thought they may need. There is not another core, like-for-like solution that consolidates, draws insights from, and reports on Candy and BuildSmart data like Connect does,” says De Klerk.

INFORMATION & COMMUNICATIONS TECHNOLOGY

Smart devices predict unplanned downtime The reliability of equipment and a continuous power supply form a fundamental par t of business sustainability, par ticularly when it comes to production continuity and downtime avoidance.

V

ery often, little thought is given to the realistic lifespan of critical industrial equipment. Generators and uninterrupted power supplies (UPSs) frequently operate without sufficient monitoring. And equipment is seldom maintained or upgraded.

This is surprising, as a failure in equipment can result in catastrophic consequences for any company,” says Martin van Zyl, segment leader: Consumer Packaged Goods, Schneider Electric.

Monitoring “The importance of monitoring cannot be overexaggerated. At Schneider Electric, we understand the value of holistically and deeply monitoring critical equipment, using industry software solutions supported by cloud analytics and expert engineers,” adds Van Zyl. Monitoring critical industrial equipment has the following benefits: • identify and mitigate power quality issues from both internal and external sources

• improve power quality to reduce equipment failure, prolong equipment lifespan and eliminate unknown tripping and stoppage events • reduce energy cost by pinpointing savings opportunities related to operational usage, power quality mitigation measures and utility optimisation initiatives • leverage contextual information such as busbar temperature, ambient conditions, the number of operations, the loading of the equipment and other condition sensors • improve safety through connected MV (medium voltage) and LV (low voltage) switchgear – providing remote switching functionality to establish safe environments that keep employees out of harm’s way while also empowering quick response time.

Martin van Zyl, segment leader: Consumer Packaged Goods at Schneider Electric

degradation of equipment longevity and unplanned downtime.

“These issues are more common than one would expect. An estimated 70% of power quality disturbances originate within facilities and cause between 30% and 40% of downtime incidents,” adds Van Zyl. In these cases, a power management system has the analytic tools to help manufacturers understand which power quality events could adversely affect operations. Manufacturers can monitor and analyse power quality disturbances to determine the specific actions needed to correct issues. This might include the installation of power quality correction equipment, such as power factor correction capacitor banks and active harmonic filters.

Cloud analytics

While monitoring and management are great steps forward, even more insight can be Power quality issues can go unnoticed and gained through analysing collected data in have a major impact on operations and the cloud. processes, leading to equipment damage, “The benefit of Schneider Electric’s cloud analytics is that data is evaluated through machine learning tools together with R&D information; but an experienced Schneider Electric engineer will also evaluate the results and provide specific recommendations to the on-site team on how to proactively Critical equipment prevent an issue from progressing such as generators and into a safety or downtime event,” uninterrupted power explains Van Zyl. supplies often operate An example of cloud analytics without sufficient monitoring services would be monitoring a transformer’s busbar temperatures in the context of the ambient operating conditions and load profile. This will assist in understanding when these contextualised thresholds are exceeded, which will require immediate on-site intervention such as the tightening of the cable or busbar connections.

Cloud applications can evaluate a holistic data set and its relation to critical assets such as a transformers or UPSs to identify potential issues arising long before a failure occurs.

Power quality

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ROADS & BRIDGES

Kerb and drainage system integration With the increase in unseasonal stormy weather, the need for efficient and suitable drainage is on the rise, par ticularly for projects that have road or road upgrading elements and related components.

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ocla has recently upscaled its already extremely versatile combined kerb and drainage system – Beany Block and Max Tech. The system is specifically designed for roadway drainage, with kerbs on either side, as well as parking areas and general open spaces where drainage is required in strips, crossing these areas.

The Beany system consists of a series of Base Blocks of standard channel section and Top Blocks of inverted channel section with an opening in one side face, collecting water horizontally into the channel section. The Max Tech system consists of the same Base Block channel section but with Max Tech Dog Bone slabs placed on top, creating a surface and openings level with the pavement area and hence collecting water vertically into the channel. When laid end to end, they form kerb and/or surface water drainage units strong enough to withstand normal traffic loading.

A standard Top and Base Block is 500 mm in length, with each block having an approximate mass of 70 kg, while Max Tech slabs are

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250 mm in length (along the channel) and weigh approximately 32 kg each. The Top Block oval openings give an aesthetic appearance and a continuous line of these blocks provides greater inlet capacities than conventional kerb inlets, with less risk of blockage or damage. The Max Tech oval slot allows for an approximately 18% open area for catchment. Standard blocks may be used for curve radii of 30 m or more; smaller spaces are managed by grouting up wedges created between adjacent blocks.

Key advantages Problems such as insufficient fall and conflicting levels of service mains and cables are eliminated with the Beany Block and Max Tech systems. The precast elements, shallow excavations and easily formed drainage profiles offer substantial time savings over conventionally designed options.

The Beany Block is a substitute for kerbs, stormwater pipework (250 mm to 300 mm diameter pipes), kerb inlets and parts of footways, while Max Tech

The Beany Block and Max Tech combined drainage and kerb system is aesthetic and efficient

eliminates complex cross-falls and provides a continuous collection and carriage system.

Contractual claims due to damaged services are far less likely to occur compared to conventional drainage due to the shallow excavations involved in the installation of the system.

Suitable applications There are numerous applications for the Beany Block and Max Tech combined drainage and kerb system, namely: • where high inlet capacity is required • wide carriageways • as a division between vehicle and pedestrian/bicycle lanes with drainage from both sides • parking areas • taxi ranks and bus depots • wash bays and vehicle service areas • median islands and industrial areas • drainage around buildings and walkways • toll plazas • intersections of roads and driveways.

The Beany Block drainage system has undergone strength tests and the Top and Base Blocks have been designed to withstand accidental 80 kN axle loading.

In turn, (unreinforced) Max Tech has been designed for 30 kN axle point loads.

Overall, durability and aesthetics come together to form highly efficient stormwater management systems.

ROADS & BRIDGES

Valuable systems upgrade for AECI Much Asphalt A major operating system software upgrade is enabling AECI Much Asphalt to identify and standardise best practice across its manufacturing facilities in South Africa.

T

he upgrade has included modernising its database to enable the generation of live plant reports, which can be used to confirm the integrity of the asphalt and evaluate consistency across 15 manufacturing plants. Data from the plants, as well as weighbridges and laboratories, can be produced and interpreted on the same platform to link all aspects of the production process – from design through to distribution for each plant.

“Our new system offers the unique ability to provide access to a significant range of live data, enabling our managers to make immediate, informed decisions,” says Colin Brooks, group plant technical manager.

Analysis of the reports enables AECI Much Asphalt to compare international benchmarks with its own internal targets.

Data provided includes the date and time of the batch, the recipe used, and measurements such as rate of production, bitumen tank temperature logging, bitumen and fuel level readings, as well as cold feed outputs.

“From this important information, we are able to create a standard template, which can compare efficiency and quality in terms of start-ups, number of mixes, length of runs and other data,” says Brooks.

“The benefit to our customers will be our ability to deliver a better-quality product on spec and on time. As we improve and standardise the best practices across all plants, we will also see an improvement in our energy usage, which will help to reduce our carbon footprint,” he continues.

Colin Brooks, group plant technical manager, pictured at the AECI Much Asphalt Eerste River plant in Cape Town

Adroit interface AECI Much Asphalt uses an Adroit operating software, which was developed in collaboration with Technopark Automation & Control (TAC) about 20 years ago. An upgrade to the Adroit software was required due to the shift to Windows 10. It was decided to dovetail this process with the conversion of the database from Microsoft Access to SQL, to standardise data capturing across all manufacturing processes from start to finish. Using the Adroit interface, TAC carried out all the back-end programming and changes.

The upgrade took place over a two-year period. “While we previously captured our data, the challenge was that all the pick-up points were allocated to different places in the database, and so we would have to sieve through the data to make comparisons between plants,” says Brooks.

“We are planning to upgrade further to enable the live tracking of stock usage, which will assist in achieving quick and efficient stock management,” he explains.

Training has been provided to staff on the generation and interpretation of the reports. While some aspects of the process still need to be operated manually at this stage, Brooks says AECI Much Asphalt expects the system to be fully automated by the end of 2021.

“The Benoni plant is the only one that is not yet integrated, as it uses a different operating system. We can generate reports, but not yet live data in real time.

We are liaising with the manufacturer of the Benoni plant and are confident that a solution will be available soon,” Brook concludes.

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ENVIRONMENTAL ENGINEERING

Installation of a wood chip blanket on an attenuation pond embankment in Gauteng

Designing and building bio-engineered structures Gabion baskets and gabion mattresses are among the oldest and most proven environmentally engineered structures. At times, however, the strategic use of plants and geotextiles can work equally well on their own, or in combination, says Louis Cheyne, managing director, Gabion Baskets. By Alastair Currie

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hile serving effectively as mass gravity retaining wall structures, gabion baskets and gabion mattresses are also ideal for slope and riverbank stabilisation. Their main purpose here is erosion control – an especially important intervention given increasing stormwater runoff within urban centres.

Previous land use, as well as deforestation, fires, droughts and the drying out of wetlands are also all major causes of erosion in both urban and rural areas. This is compounded by the invasion of alien species, like black wattle, which displace indigenous plants that were naturally suited to anchoring soils via their water-wise roots.

“Over the years, there’s been increasing appreciation for the role that plants play

as nature’s bio-engineers. While we’ve traditionally focused on supplying solutions for ‘hard’ engineering designs, we are seeing a growing interest in the ‘soft’ side of environmental engineering. Here, the use of plants can complement, enhance or even replace conventional techniques. Either way, today’s emphasis is on green designs that blend in and coexist with their surroundings,” says Cheyne.

and lizards. The soil contained in the gabions for this purpose is held in place by geotextiles to prevent fines loss. The use of tickey creepers is also ideal for growing up and over gabion structures.

“Essentially, there are endless variations of soft and/or hard interventions,” says Cheyne, adding that environmental engineering specialist Gabion Baskets provides installation training for industry. This includes SMME and community-based projects.

River Willow anchor system: a hybrid approach A classic example of a system that combines hard and soft approaches is the employment of shrubs to either green or help anchor retaining systems. Globally, the use

Permeability The one major advantage of gabion baskets is that they are formed using double-twisted galvanised wire mesh filled with rocks that are permeable to a greater, or lesser, degree, according to the design. This means they are also perfect for establishing plants, as well as forming a habitat for fauna like insects

This environmentally engineered solution combines a range of interventions that include gabion weirs, and a geocell-lined channel planted with vegetation. Soil blankets on the channel banks have been seeded with plants for further erosion protection (Credit: HansKingSRS)

Young tree cuttings planted to grow through and above the gabion retaining wall

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ENVIRONMENTAL ENGINEERING of young tree cuttings, like river willow, is especially popular.

“Each plant has its own characteristic tensile root strength, so that’s a factor to consider.

Choosing the right tree cutting is equally important. Willows, for example, are flexible, woody plants and their roots help increase bank stablilisation. In contrast, stiffer plants should be avoided, as these might act as levers as they grow and work against the gabion retaining structure,” says Cheyne.

In terms of installation, these willow cuttings – typically measuring up to 2.5 cm in diameter and preferably less than a year old – can be inserted in-between the 1 m x 1 m gabion baskets that form a conventional retaining wall and then planted into the rear soil embankment. As the trees mature, their roots firmly gain hold and increase the shear strength. In the meantime, the front face will become progressively greener as the shrubbery grows through and around the gabions. The top of the gabion wall can also be covered with a geotextile and topsoil, and then planted to complete the overall effect.

A soft approach The other option is to build a similar retaining structure where gabions are not used. Instead, stepped-back, high-strength geogrid material, covered with compacted soil, forms the horizontal layer works to create the retaining structure. Again, live cuttings are positioned at intervals to grow back and through the external face.

In some cases, it is also possible to design an erosion control slope with loose rocks resting on a soil blanket. Sausage gabions can also be employed, which are secured with live tree stakes to hold everything together.

Where the intention is to form gradually sloping terraces, another option is the GabBloc system. These are mini gabions used to retain embankments that can be interspersed with flower beds.

A slope stabilised with a gabion mattress. Note the return of the mattress into the top of the bank, which is essential to ensure it is firmly anchored and doesn’t slide down. A planted topsoil layer promotes the growth of vegetation

A few weeks later, the vegetation is now well established

“We’ve also supplied gabions with a pocket inside. Once these pockets are planted, the external wall is attractively vegetated,” Cheyne explains.

Erosion control blankets Within the soft engineering space, there are a host of other interventions, such as the deployment of erosion control soil blankets where the main aim is to achieve soil protection. An example would be the covering of the slopes bordering a river or attenuation pond.

Their use is also employed when greening gabion mattress slopes or the top of a retaining wall. Overlying the gabion structure, the blanket is covered with topsoil and planted.

The blanket’s main purpose is to keep the soil moist and cool during the initial plant growing phase. A further advantage is that these blankets degrade into the soil over time, enriching the nitrogen content.

Architectural gabions There are times, however, where gabions are used purely for aesthetics. A good example is the architectural market, where Gabion Baskets is experiencing strong demand for

its welded-steel square mesh range. Unlike woven mesh, which is designed to exhibit some degree of flex, welded mesh products are intentionally rigid. Typical applications include internal and external building cladding, fencing, and property boundary walls.

Welded mesh can also be attractively greened. Examples include plants designed to cascade downwards from the top of these structures.

Strategic partnerships “The science of environmental engineering is definitely experiencing a resurgence, and the impact of extreme weather due to climate change is one major factor,” says Cheyne.

“Another is a desire to reverse the harsher elements of our concrete landscape by going green.

“Combined with training, our strategy is to work closely with our network of contractors and consulting engineers to provide them with fit-for-purpose solutions,” he continues.

A recent example is a new strategic alliance with Western Cape-based consulting firm HansKingSRS, a leading expert in the field.

In addition to river stabilisation, HansKingSRS provides hydraulic and hydrological consulting services, and specialises in the planning of soil conservation structures.

“A crucial component of environmental engineering is understanding hydrology and water velocity. That’s the starting point for deciding on the optimum bio-engineered design,” Cheyne concludes.

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ENVIRONMENTAL ENGINEERING

Gulley in 2017

Inside a section of the gulley in February 2019

An aerial view taken in September 2020, showing the extent of the erosion The gulley just as construction began in 2020

Innovative rehabilitation of a deep gulley Vergelegen Wines in Somerset West is very proud of its farm’s heritage and takes great care of the environment.

Among other things, at its own cost, the company has cleared more than 2 000 hectares of alien vegetation to create a fynbos reserve. One of the most recent interventions entailed a major erosion control project.

By Hans King, Pr Eng Client: Vergelegen Wines Project design and management: HansKingSRS Construction: Martin & East Year construction completed: 2021

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F

ollowing the 2013 storm season, the appearance of a small gulley on the Vergelegen Wines farm was cause for concern. From 2017, this gulley suddenly accelerated in size as the dispersive weathered Cape granite soils below were

exposed and eroded rapidly. Between 2017 and 2018, the gulley increased from 30 m to 400 m in length, and from 2 m to 6 m deep. Downstream from the gulley, an area of Lourens River fynbos was smothered by the sediment.

Plans for rehabilitation using cascades of weirs and other measures were prepared in early 2018 and the lengthy environmental approval process was started. An attempt was made to have the gulley recognised as a disaster and shorten the approval process – but, because the damage began in 2013, this was not allowed. The approval process took nearly a year, while the gulley grew even longer and deeper.

ENVIRONMENTAL ENGINEERING

Technical challenges

The solution implemented

The first challenge to the design was the wetland specialist’s requirements. The natural water table in the area had to be restored as far as possible to its original level, so that natural vegetation in the areas adjacent to the gulley would not be negatively impacted by the drying out of the soil. The implication of this was that the floor of the rehabilitated gulley had to be as close to the original ground level as possible, and this necessitated the construction of weirs 5 m to 7 m high – a potentially very costly exercise.

A serious challenge to the stabilisation of the gulley was the nature of the subsoil.

Being highly dispersive, water flowing over it erodes it very quickly. To address this, steps had to be taken to make sure that water did not flow over the exposed, decomposed granite soil. In addition, the flow velocity of water had to be kept low so that the topsoil placed on top of the weathered granite was unlikely to be washed away.

At the design stage, there was an understanding that the depth of the gulley might well increase by the time the necessary approvals had been obtained and a contractor was finally on-site. The design had to be adaptable so that it could accommodate changes to the gulley shape.

A cascade of seven gabion weirs was planned to reduce the slope of the gulley from 6% to around 1.5%, thereby reducing the flow velocity. Between the weirs, the gulley was widened to 4 m as a primary measure to reduce the flow velocity in the channel.

To further increase the hydraulic surface roughness (and reduce flow velocities), it was planned to cover the channel with an assortment of indigenous wetland plants.

These plants would have the added benefit of binding the soil with their roots.

A perspective of the site taken in April 2021, prior to revegetation

Construction in progress during October 2020

Novel ideas To drastically lower the construction cost of the gabion weirs, the gulley under the weirs was first filled with cement stabilised soil, so that most of the weir spillways only had to be 1 m high. Traditionally, the weirs would have been constructed from the base of the gulley floor and the cost of such structures would have made the project unaffordable.

This cement-stabilised soil had the added advantage of being able to adapt to the shape of the gulley – which a built structure could not do. Trials were done using the decomposed granite and varying cement concentrations to determine a mix suitable for the project. Steps were taken to ensure that the topsoil layer spread over the

A Multi-Cell section being filled with topsoil

weathered granite base was not washed away before the vegetation could be properly established. A 150 mm thick Kaytech Multi-Cell was placed over the formed channel and the topsoil was placed into the Multi-Cell. A trial onsite, conducted prior to the finalisation of the design, proved that the MultiCell retained more than 90% of the soil placed in it when subjected to flow velocities of 2 m/s.

To achieve maximum support to the water table, the level of the weirs was planned so that there was just enough clearance between the spillways and the natural ground level for the expected floods to remain in the depression. This resulted in the depression between the weirs remaining between 1 m and 2 m below the natural ground level.

From an overall project perspective, the final objective was achieved thanks to an enduring design that blends in and coexists with the environment.

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RECYCLING

Socio-economic factors affecting separation at source in Drakenstein Municipality With national government’s Extended Producer Responsibility Regulations coming into force, the collection for recycling of most post-consumer packaging and products is now to be managed by the relevant producer responsibility organisations. This is focusing attention on effective recycling collection systems. By Hugh Tyrrell & Liza Volschenk*

S

eparation at source is regarded worldwide as the preferred method to diver t high-value recyclable materials into the recycling economy. This is especially applicable to middle- and upper-income households combined with a regular kerbside collection service.

Research by the CSIR in 2012 estimated that of the 19 million tonnes of municipal solid waste going into landfills in South Africa, 25% is made up of recyclable materials. Using the CSIR Phase 2 Waste Roadmap (2011), the average economic value of these materials lost through landfilling is some R4 billion each year.

Most of the large metros and many medium and smaller municipalities have introduced separation-at-source recycling, using a two-bag, wet/dry separation system with regular kerbside collections.

This requires householders to separate their recyclables – plastic, paper, tins

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and glass – into a free bag (usually clear) provided by the municipality. The bag of recyclables is collected and swopped for a fresh bag each week so that recycling can continue.

A study was first conducted in 2019 in the Western Cape’s Drakenstein Municipal Area by Liza Volschenk of the University of Johannesburg. This research analysed the socio-economic factors affecting household

participation and was followed up with an article published in the African Journal of Business and Economic Research in March this year.

Drakenstein incorporates the towns of Paarl and Wellington, where six middleand upper-income suburbs were identified by the municipality to be part of the survey.

The sample size was 240 households, which comprised mostly white Afrikaansspeaking residents with household size ranging from one to ten, with an average of three members.

The research considered a range of variables affecting separation-at-source par ticipation, including gender, age, education, income, whether schoolgoing children were par t of the household, and what could work best to inform householders about recycling.

Analysis of the data coming out of the research confirmed some common assumptions and pointed to other useful findings. As could be expected, households where women were in charge of waste management were also those where recycling was highest.

Income is generally an indicator of recycling par ticipation, often because higher disposable income results in greater consumer spending and large amounts of packaging materials to be dealt with. The findings, however, were inconclusive on this because the probability to recycle

RECYCLING

was most significant only in the R6 401 to R25 600 per month income category, and not beyond that.

Age came up as a factor, with the older the average age of family members being a predictor of higher recycling participation.

Retired people may have more time available for waste separation, and may also be more conscious about the world they are leaving for their children and grandchildren.

The length of residence in a household was shown to have a significant effect in recycling par ticipation. Residents living longer in houses in older suburbs are perhaps more familiar with waste removal processes and, generally, take more civic responsibility for the upkeep of their surroundings.

Interestingly, the number of people living in a household indicated an increase in the probability of recycling. The greater amount of waste materials to be recycled and more family members available to do the separation may possibly be a reason.

A strong finding was that schoolgoing children as part of a household predicted a 16.3% higher recycling par ticipation.

Environmental education and projects on waste management at school spill over and provide pressure, as well as guidance, at home for family participation in separation at source.

As regards communication about separation-at-source recycling, the probability of recycling increased by

South Africa

6.4% using social media and by 13.1% if households have sufficient information from media generally.

Most significantly, the results indicated that access to regular provision of free recycling bags for householders in exchange for full ones increased the probability of them recycling to 42%.

Recommendations While the results of the study are area-specific, recommendations arising from it can be applied to other local authorities managing separation-at-source programmes.

Adequate and ongoing information to residents is vital. A WhatsApp group, the local community newspaper and leaflets were high on the list of priorities that came up among Drakenstein householders. Regular feedback on tonnages being collected, jobs created, water and energy conserved can further motivate householders to continue recycling until it becomes routine.

Working with nearby schools to introduce learning content about responsible waste management and the municipality’s separation-at-source system clearly brings benefits back home. A good working relationship with the municipal communications depar tment would be useful for their support to publicise a programme’s launch and progress.

While long-term residents may know more about how the service works, new residents moving to the area need to be assisted with

information about the service. A ‘starter pack’ containing an information leaflet, fridge reminder card and bags to get started could be prepared for them. Estate agents will know who is coming and going, so would be good partners for distribution.

As highlighted, it is essential to ensure that households who have taken the trouble to start with separation at source continue to get their bags of recycling swopped for fresh ones each week.

Consideration could be given to providing smaller wheelie bins instead of bags, which could make for financial savings over time. Either way, a responsive, efficient and ‘customer-oriented’ ser vice approach is seen as key to recycling collection success for municipalities. *Hugh Tyrrell is a leading consultant in designing communication and behaviour change campaigns to increase participation in recycling programmes. Liza Volschenk is a researcher and lecturer at the University of Johannesburg.

Reference: Volschenk, L., Viljoen, K., Schenck, C. (2021) ‘Socio-economic factors affecting household par ticipation in curb-side recycling programmes: evidence from Drakenstein Municipality, South Africa’, African Journal of Business and Economic Research, Vol. 16 (Issue 1), March 2021, pp 143 – 162.

PROCUREMENT

Testing the logic of the bid scoring process South Africa’s price-laden bid scoring process is meant to yield a fair and competitive result that promotes transformation. However, when the formulae used are tested using hypothetical examples, the opposite result could intentionally or unintentionally be achieved. The fact that a linear approach is taken further complicates the problem.

By Gundo Maswime*

T

he allocation of points for bid price in South Africa is based on the following formulae:

Where: Ps = Points scored for price of tender under consideration Pt = Rand value of offered tender consideration Pmin = Rand value of lowest acceptable tender

There are certain particularities or oddities about these formulae that require a sober reflection by both service providers and policymakers alike. Using the second formula (2), the point is illustrated using arbitrary bidders. Let’s assume three bidders submit bids for a road construction project as per Table 1.

Keeping the bid ranks as they are, let’s introduce a fourth bidder, Gamma Pty at R20 million, and observe the effect of this new bid on the other bids – see Table 2.

What is immediately obvious is that the introduction of Gamma Pty has suddenly made Theta Pty the preferred bidder even though neither the quality of their bid nor their bid price have changed. This characteristic of the formula means that every time the bid

Gundo Maswime

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adjudication committee refers a report back to the bid evaluation committee for an excluded bidder to be included in the evaluation, all the other bids must be re-evaluated if the ‘added’ bidder submitted a price lower than all evaluated bidders.

This oddity built into the price scoring formula raises questions about the concept of value for money. If the other offers never changed, it makes the concept of value for money a mirage. This concept of value for money is called ‘cost-effectiveness’ in section 217 (1) of the Constitution of the Republic of South Africa. It is a constitutional requirement for the procurement system to meet.

Value for money versus lowest price What this example emphatically puts across is

PROCUREMENT

TABLE 1 Received bids

Company name

Bid price

Price score Functionality or quality score Using formula (2) Alpha Pty R30 000 000 90 points 40 Beta Pty R35 000 000 75 points 60 Theta Pty R40 000 000 60 points 65 Note: This is fictitious data, for illustration purposes only

BBBEE score Total points RANK 7 1 7

137 136 132

1 2 3

TABLE 2 Received bids with additional bidder

Company name

Bid price

Alpha Pty Beta Pty Theta Pty Gamma Pty

R30 000 000 R35 000 000 R40 000 000 R20 000 000

Price score Using formula (2) 45 points 63 points 67.5 points 90 points

that it is a fallacy to associate value for money with lowest price. It also means that giving a weight of 90% and 80% to bid price requires a review, especially allocating 90% weight to the bids that are more sophisticated and thus presenting a bigger risk. It must be argued, therefore, that the smaller projects must, against this background, have a larger weight on price and vice versa. It should be noted that most countries allocate a weight of 60% to price and indeed South Africa has a unique set of circumstances that demand independent and contextual thinking and approaches to procurement.

Functionality or quality score BBBEE score Total points RANK 40 60 65 30

7 1 7 1

The South African formula is also one of the extremely few that is linear and capable of yielding a negative score. The linearity of the formula means that a bidder submitting double the price of the lowest bidder gets zero points for price. Logically, submitting double the price of the lowest bidder should yield half the points the lowest bidder receives for price. This logic may also raise questions of constitutionality if what section 217 (1) of the Constitution means by fairness is closely examined.

Who stands to benefit?

While probing the constitutionality of the formula, we may also need to ask the question of who stands to benefit from a price-laden bid scoring process. In construction, the more established and experienced contractors can be distinguished by their ability to master their overheads and extract profit by invoking their optimised site repertoire. It means they can lower their bid price considerably. Therefore, the larger companies have an advantage on what weighs 90% in bid points allocation.

This does not augur well for transformation or equitability.

This is all the more reason why the formula should reduce the weight of price, as it is both an affront to cost-effectiveness (or value for money) and counter-transformative in that it puts a 90% weight on price, thereby giving the established players an unfair advantage.

The points for price formula, as it stands, presents fertile opportunities for collusion.

Noting the effect of introducing Gamma Pty, it can be deduced that an arithmetically astute contractor can submit a second decoy bid with a lowered-to-the-bone price – and very minimal

92 124 139.5 121

4 2 1 3

functionality and BBBEE scores – to embellish their chances of another bid winning with a higher price than the honestly low price of a competitor.

A proposed solution To solve this conundrum, the following approach to bid evaluation is advised. First, the technical evaluation of bids must begin by independently estimating what the ideal value of the work, without any profit margin, should be. This value must be noted by the committee.

Second, the average of all bid prices (minus the statistically determined outliers) must be noted. A mid-point price between the average price and the ideal value of the work must then be computed. This mid-point price must be used in place of the minimum price in the procurement formula above.

Of course, there should be two modifications to the formulae. The first is that a bid price must always yield a positive value. That means the equation must be an absolute equation or a modulus. The second is to reduce the weight of the points for price to a tentative 65/35 and 75/25 split, with the latter reserved for smaller projects and the former reserved for larger projects.

To achieve the right result, supply chain staff should focus on compliance documents, while technical staff should focus on technical evaluation. That will ensure that price and fairness are combined with quality to ensure sustainable construction practices. *Gundo Maswime is a lecturer at the University of Cape Town and researcher in public infrastructure.

IMIESA May 2021

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BUILDING SYSTEMS

Crucial fire standard updated The recent publication of a revised version of SANS 10139 – ‘Code of practice for design, installation, commissioning and maintenance of fire detection and alarm systems in non-domestic premises’ brings South Africa in line with fire safety standards similar to those in the UK and EU.

S

ANS 10139 is based on British Standards BS5839-1, which was updated several years ago after 14 fatalities occurred at an old age home in Lancashire. The revised South African National Standards (SANS) version was published on 3 May 2021.

The Standards Division of the South African Bureau of Standards (SABS) maintains and develops several national standards aimed at ensuring the protection of life and property from fire and fire-related damage.

“The revision of SANS 10139 will benefit the fire protection industry as it clarifies all requirements and will ultimately eliminate the confusion experienced by the protection industry,” explains Laura Swart, chairperson of the SABS Technical Committee.

“This in turn will result in a more effective use of the national standard, thus improving firefighting and the job of saving lives, as well as preventing the loss of property. The standard also aims to mitigate the risk of Volunteers saving historic materials from the Jagger Library archives, which were damaged in the recent fire at the University of Cape Town

52

IMIESA May 2021

failure of fire detection and fire alarm systems in and around buildings,” she continues. The revision of the national standards was made possible by valuable collaboration with the Fire System Inspection Bureau, the Fire Detection Installers Association, and the South African insurance industry.

UCT and Charlotte Maxeke Hospital fires The revised SANS 10139 comes at a time when South Africa has recently experienced two especially devastating fires. The first were the wildfires that swept the slopes of Cape Town’s Table Mountain and spread to the University of Cape Town. The fires burnt sections of the historic Jagger campus library and forced the evacuation of thousands of students. The second was the incident where 700 patients were evacuated from Johannesburg’s Charlotte Maxeke Hospital after a fire blazed through parts of the medical facility.

The seriousness of fire is often overlooked, and its impact often underestimated. For this reason, it is crucial that a national set

Laura Swart, chairperson of the SABS Technical Committee

of guidelines and rules for the designers and installers of fire protection systems is provided for them to follow and uphold. The costs of fire within South Africa run into the billions and need to be prevented.

SANS 10139 REVISIONS TO NOTE • Updated recommendations about the need for a fire detection system, variations from the standard, system components, detection zones, communication with the fire services, staged fire alarms, and manual call points • Updated requirements for smoke detectors • Updated requirements for spacing and placing of automatic fire detectors • Updated measures to limit false alarm • A commentary on inspection and servicing has been added

VEHICLES & EQUIPMENT

Cooperation spurs transition to battery power From September 2021, the modular, rechargeable construction equipment battery developed by Wacker Neuson will also be compatible with equipment made by the company’s cooperation partner Bomag.

O

ur interchangeable battery has the potential to power a wide range of construction equipment. By enabling another manufacturer to use our battery, we are further accelerating the adoption of emissionsfree construction equipment and underscoring Wacker Neuson’s commitment to fast-tracking carbon reductions,” explains Stefan Pfetsch, managing director of the Wacker Neuson production site in Reichertshofen, Germany.

This is the company’s competence centre for compaction.

At present, the battery can power three vibratory plates, three battery-powered rammer models and one internal vibrator system from Wacker Neuson’s zero-emissions range. Wacker Neuson also fields a range of electrically powered excavators, wheel and track dumpers, and wheel loaders that form part of its zero-emissions portfolio.

Wacker Neuson and Bomag have agreed to use the same battery for their rammers so customers who decide to invest in a battery and charger will be able to use them across an even broader range of construction equipment.

“Through our cooperation with Wacker

Neuson, we are leveraging the experience of two innovative equipment manufacturers to offer our customers practical added value through the use of zero-emissions construction equipment,” explains Ralf Junker, president of the Bomag Group. As a result of the cooperation agreement, Bomag will launch the first battery-powered tamper in September this year – further products are at an advanced stage of development.

“Already today, a complete urban construction site can be operated without any direct emissions with our portfolio. Up to 93% of CO2 emissions can be saved compared to a conventional product of the same class,” adds Alexander Greschner, CSO of the Wacker Neuson Group.

“These products also deliver clear cost benefits. In some countries, for example, they enable customers to save on CO2 tax. Other governments proactively support the use of electric machines through incentives or by favouring contractors who promise lower CO2 emissions in tenders,” he continues.

Innovation leader Wacker Neuson launched the world’s first

TOP Batteries are interchangeable with other machines within Wacker Neuson’s zero emissions portfolio ABOVE Wacker Neuson’s BP1400 battery has an energy capacity of 1 400 Wh

battery-powered rammer back in 2014 and currently offers two interchangeable batteries with power capacities of 1 000 Wh and 1 400 Wh. A uniform charging structure and rapid setup of a charging management system make day-to-day life on construction sites easier and increase acceptance levels for this technology.

“We are committed to offering practical, strictly customer-centric solutions. Our customers appreciate the freedom to use products from different manufacturers, and they also expect this freedom with batterypowered equipment,” says Pfetsch.

“We are now delivering on this need, while also driving more widespread adoption of future-proof electric products,” Pfetsch concludes.

IMIESA May 2021

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IMESA

IMESA AFFILIATE MEMBERS PROFESSIONAL AFFILIATES

AECOM siphokuhle.dlamini@aecom.com AFI Consult banie@afri-infra.com lunga@alakeconsulting.com Alake Consulting Engineers AQUADAM (Pty) Ltd sales@aquadam.co.za ARRB Systems info@arrbsystemssa.com Asla Construction (Pty) Ltd johanv@asla.co.za Aveng Manufacturing Infraset werner.booyens@infraset.com Bigen Africa Group Holdings otto.scharfetter@bigenafrica.com BMK Group brian@bmkgroup.co.za Bosch Munitech info@boschmunitech.co.za mail@boschprojects.co.za Bosch Projects (Pty) Ltd BVI Consulting Engineers marketing@bviho.co.za CCG puhumudzo@ccgsytems.co.za / info@ccgsystems.co.za Civilconsult Consulting Engineers mail@civilconsult.co.za Corrosion Institute of Southern Africa secretary@corrosioninstitute.org.za Development Bank of SA divb@dbsa.org.za Dlamindlovu Consulting Engineers & Project Managers info@dlami-ndlovu.co.za DPI Plastics Farhana@dpiplastics.co.za EFG Engineers eric@efgeng.co.za Elster Kent Metering Mark.Shamley@Honeywell.com EMS Solutions paul@emssolutions.co.za ERWAT mail@erwat.co.za GIBB marketing@gibb.co.za GIGSA secretary@gigsa.org GLS Consulting nicky@gls.co.za Gorman Rupp Cordeiro@gormanrupp.co.za Gudunkomo Investments & Consulting info@gudunkomo.co.za Hatch Africa (Pty) Ltd info@hatch.co.za Herrenknecht schiewe.helene@herrenknecht.de Huber Technology cs@hubersa.com info@edams.co.za Hydro-comp Enterprises I@Consulting info@iaconsulting.co.za Infrachamps Consulting info@infrachamps.co.za INFRATEC info@infratec.co.za INGEROP mravjee@ingerop.co.za Integrity Environment info@integrityafrica.co.za IQHINA Consulting Engineers & Project Managers info@iqhina.co.za iX engineers (Pty) Ltd hans.k@ixengineers.co.za JBFE Consulting (Pty) Ltd issie@jbfe.co.za JG Afrika DennyC@jgafrika.com KABE Consulting Engineers info@kabe.co.za Kago Consulting Engineers kagocon@kago.co.za Kantey & Templer (K&T) Consulting Engineers ccherry@ct.kanteys.co.za Kitso Botlhale Consulting Engineers info@kitsobce.co.za general@lwt.co.za Lektratek Water Makhaotse Narasimulu & Associates mmakhaotse@mna-sa.co.za Malani Padayachee & Associates (Pty) Ltd admin@mpa.co.za Maragela Consulting Engineers admin@maragelaconsulting.co.za Mariswe (Pty) Ltd neshniec@mariswe.com Martin & East gbyron@martin-east.co.za M & C Consulting Engineers (Pty) Ltd info@mcconsulting.co.za Mhiduve adminpotch@mhiduve.co.za Mogoba Maphuthi & Associates (Pty) Ltd admin@mmaholdings.co.za Much Asphalt bennie.greyling@muchasphalt.com Mvubu Consulting & Project Managers miranda@mvubu.net NAKO ILISO lyn.adams@nakogroup.com Nyeleti Consulting merasmus@nyeleti.co.za Odour Engineering Systems mathewc@oes.co.za amarunga@prociv.co.za Prociv Consulting & Projects Management Rainbow Reservoirs quin@rainbowres.com maura@re-solve.co.za Re-Solve Consulting (Pty) Ltd Ribicon Consulting Group (Pty) Ltd info@ribicon.co.za francisg@rhdv.com Royal HaskoningDHV info@sabita.co.za SABITA mberry@safripol.com SAFRIPOL SAGI annette@sagi.co.za info@salga.org.za SALGA SAPPMA admin@sappma.co.za / willem@sappma.co.za SARF administrator@sarf.org.za.co.za SBS Water Systems mava@sbstanks.co.za Sembcorp Siza Water info-sizawater@sembcorp.com Sigodi Marah Martin Management Support lansanam@sigodimarah.co.za garths@sivest.co.za SiVEST SA Sizabantu Piping Systems (Pty) Ltd gregl@sizabantupipingsystems.com SKYV Consulting Engineers (Pty) Ltd kamesh@skyv.co.za capetown@smec.com SMEC gen@sobek.co.za Sobek Engineering director@sasst.org.za Southern African Society for Trenchless Technology jomar@srk.co.za SRK Consulting Star Of Life Emergency Trading CC admin@staroflife.co.za Syntell julia@syntell.co.za TECROVEER (Pty) Ltd info@tecroveer.co.za TPA Consulting roger@tpa.co.za V3 Consulting Engineers (Pty) Ltd info@v3consulting.co.za Vetasi south-africa@vetasi.com VIP Consulting Engineers esme@vipconsulting.co.za VNA info@vnac.co.za VUKA Africa Consulting Engineers info@vukaafrica.co.za Water Institute of Southern Africa wisa@wisa.org.za Wam Technology CC support@wamsys.co.za Wilo South Africa marketingsa@wilo.co.za WRCON ben@wrcon.co.za WRP ronniem@wrp.co.za WSP Group Africa ansia.meyer@wsp.com Zutari Rashree.Maharaj@Zutari.com

VEHICLES & EQUIPMENT

SPECIALITY DOZERS FOR LOCAL LANDFILL SITES

E

LB Equipment’s latest range of dedicated Dressta landfill dozers is optimally designed for spreading and compacting waste, meeting high production demands on municipal sites. Recent sales include the delivery of a Dressta TD-15M LA dozer to a local municipality in the Dundee region of KwaZulu-Natal. This machine, which is designed for mid-sized landfills, will be deployed in place of previously leased equipment. The Dressta TD-15M LA joins two MST backhoe loaders supplied previously by ELB Equipment.

“Machines like this tailor-made Dressta landfill machine and its bigger counterparts for larger landfills are a sensible alternative. Being specially designed for this type of operation, its running gear, tracks, filtration systems and fans, as well as service points, are designed to work for prolonged periods of time with little intervention required from the operator or service teams,” says Tshepo Mathekgane, tender sales manager for ELB Equipment.

The power to perform The Dressta TD-15M LA dozer has an operating weight of approximately 15 t and is powered by a 142 kW Cummins diesel engine with full power shift transmission. Key performance elements include a highly efficient torque converter, lubricated track systems, plus the machine’s hydraulic lift, tilt and angle blade. Comfort and safety equipment include a standard air conditioner and fully enclosed rollover-protection cab.

To thrive in its tough environment, the Dressta TD-15M LA also comes equipped with robust features that include: • a reversible fan and self-cleaning radiator • a semi-U blade with trash rack and increased blade capacity • track shoes with clean-out holes • steel debris deflector bars located below the engine • tank guards to protect fuel and hydraulics reservoirs.

These features – combined with ELB Equipment’s one-year or 2 000-hour warranty – make a strong business case for local municipalities.

ELB Equipment’s Nadia Nundkisun, tender coordinator, and Tshepo Mathekgane, tender sales manager, beside a generalpurpose Dressta dozer

IMIESA May 2021

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HEALTH & SAFET Y

HEALTH AND WELL-BEING IN CONSTRUCTION health (OH) and PH promotion on projects, which should be integral components of industry programmes.

The advent of Covid-19 has hopefully engendered a realisation that there are more than just ‘safety’ issues that must be addressed in terms of safety and health (S&H) practices in workplaces.

By Professor John Smallwood and Professor Fidelis Emuze*

H

gaps are mental health, workforce well-being, workforce engagement, H&S, and productivity.

Key H&S issues Study findings

istorically, the South African construction industry has focused on the ‘safety’ component of S&H, as opposed to the ‘health’ component, despite the ‘health’ issues being more pronounced and more serious in nature, depending on the occupational disease (OD). ODs include, among others, occupational asthma, bronchitis, and pneumoconiosis such as asbestosis and silicosis.

In terms of Covid-19 and future pandemics, such ODs constitute ‘underlying diseases’ and – as with primary health (PH) issues such as addiction, AIDS, respiratory diseases, or disorders such as asthma, cancer, pneumonia, and tuberculosis – they marginalise the human body’s immune system. Therefore, the built environment needs to address occupational

It can be concluded that mental health and well-being have become the predominating H&S issues, even though well-being and H&S are ranked joint first in terms of the top five issues. This is notable as, in recent years, W099 ‘Safety and Health in Construction’, a joint venture partner of W123, was amended to ‘Safety, Health and Well-being in Construction’. Furthermore, the PH issues constitute an opportunity for industry stakeholders to respond, as many of these are exacerbated by working conditions, or conversely engendered by poor working conditions and ODs. Built environment statutory councils, professional and employer associations, employers, and other industry stakeholders should focus on PiC issues in terms of their attempts to improve industry standards and the quality of life of the people concerned – especially OH, PH, mental health, well-being, and workforce engagement issues.

An exploratory study was undertaken

by Working Commission W123 ‘People in Construction’ (PiC) of The Conseil International du Bâtiment (CIB), which is known as the International Council for Research and Innovation in Building and Construction, to develop a PiC research roadmap.

The top five (seven, due to joint rankings) PiC issues are: workforce well-being (1=); H&S (1=); mental health (3=); workforce engagement (3=); underskilled workforce (3=); and productivity (3=), and employment practices (3=). The top five (six, due to joint rankings) research priorities are: mental health (1); workforce engagement (2=); H&S (2=); workforce well-being (4); productivity (5=); and motivation and leadership (5=).

The top five (seven, due to joint rankings) research gaps are: mental health (1); workforce engagement (2=); workforce wellbeing (2=); human rights (4); management failures (5=); women in construction (5=); and technology/new technology (5=).

Overall, the top five issues based on the mean of the percentage responses to the top five issues, research priorities and research

*Professor John Smallwood is a professor of construction management and Professor Fidelis Emuze is a research associate. Both work out of Nelson Mandela University.

INDEX TO ADVERTISERS

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15 Revaro Equipment

Lafarge South Africa Mapei South Africa

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IMIESA May 2021

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8

SMEC South Africa

49

Twinstar Precast

16

Umgeni Water

30

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