IMIESA February 2020

www.infrastructurenews.co.za

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

I N F R A S T R U C T U R E D E V E LO P M E N T • B U I L D I N G • M A I N T E N A N C E • S E RV I C E D E L I V E RY

Roads & Bridges

Life-cycle costing for gravel routes

Shisalanga Construction The sustainability leader in asphalt and roads

Water & Wastewater NRW and water security

Cement & Concrete

Shaping the future with readymix

Geosynthetics

Extending reservoir life

ISSN 0257 1978

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INSIDE

VOLUME 45 NO. 02 2020 www.infrastructurenews.co.za

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

I N F R A S T R U C T U R E D E V E LO P M E N T • B U I L D I N G • M A I N T E N A N C E • S E RV I C E D E L I V E RY

Roads & Bridges Lifecycle costing for gravel routes

Shisalanga Construction The sustainability leader in asphalt and roads

Water & Wastewater NRW and water security

Cement & Concrete

Shaping the future with readymix

Geosynthetics

Extending reservoir life

ISSN 0257 1978

V o l u m e 4 5 N o . 0 2 • F e b r u a r y 2 0 2 0 • R 5 5 . 0 0 ( i n c l . VAT )

Leading the way in asphalt and road construction, what sets Shisalanga Construction apart from the rest of their competitors is their drive to consistently deliver excellent products and services, while pushing the boundaries of innovation. P6

Regulars Editor’s comment President’s comment Africa round-up Index to advertisers

3 5 8 56

Environmentally conscious, innovative solutions from Shisalanga 6

10 13

26

WATER & WASTEWATER Good governance needs capacity

40

38

Cement & Concrete

Health & Safety

18 20

36

Environmental Engineering

17

Why health and safety is alive and well

40 42 44

45

Pipes, Pumps & Valves 21

Pipeline flexibility Innovative replacement solution

46 48

Thought Leadership 22

Engineers with a social conscience 50

Energy

Water & Wastewater A practical tool addresses water security issues Good governance needs capacity Addressing unpredictable feedwater quality Extending asset life digitally

A circular sanitation approach

14

Municipal Focus Working for the people

34

Extending reservoir life

Shaping the future with readymix Safer routes with precast The danger of cheap aggregates

Information Technology Real-time control keeps projects on track

31

Geomembranes

A wired world

Roads & Bridges Recycling pavements makes economic sense The AfriSam advantage Paving the way to an optimal road surfacing policy Mogale City teaches learners road safety Waterfront bridge swings into action N4 upgrade on track

Mastering open-channel flow measurement and monitoring

Sanitation

Cover Story

48

18

ROADS & BRIDGES Waterfront bridge swings into action

Cape Town fights to procure from IPPs 52 24 26

Vehicles & Equipment

28 30

Leading range of cut-off saws Bell concludes new BBBEE structures

CEMENT & CONCRETE Shaping the future with readymix

50

54 56

THOUGHT LEADERSHIP Engineers with a social conscience

IMIESA February 2020

1

IMESA

Joint Conference with IMESA & IAWEES

(The Institute of Municipal Engineering of Southern Africa & International Association of Water, Environment, Energy and Society) In Cooperation with RNTU & CVRU, India

CALL FOR ABSTRACTS for paper and poster presentations

THEME

SYNERGY THROUGH ENGINEERING

CATEGORIES • Environment

• Energy

• Water and Sanitation

• Financial, Legal and Regulatory

• Transport, Roads

• Data management

and Stormwater

A B S T R AC T S S U B M I T T E D BY

13 March 2020 (poster presentations and abstract submissions)

marketing@imesa.org.za | tel +27 031 266 3263

Contact Melanie Stemmer for an entry form or download it from the website.

CONFERENCE ENDORSED BY

t: +27 (031)266 3263 e: conference@imesa.org.za marketing@imesa.org.za www.imesa.org.za

IMESA ORGANISER

THE INSTITUTE OF MUNICIPAL ENGINEERING OF SOUTHERN AFRICA (IMESA) TEL: 031 266 3263 DEBBIE OR MELANIE

EDITOR’S COMMENT MANAGING EDITOR Alastair Currie SENIOR JOURNALIST Danielle Petterson JOURNALIST Nombulelo Manyana HEAD OF DESIGN Beren Bauermeister CHIEF SUB-EDITOR Tristan Snijders CONTRIBUTORS Alan Hall, Nico-Ben Janse van Rensburg, Randeer Kasserchun, Neil MacLeod, Don Ross, Andrew Skudder, Matthew Townshend, Peter van der Merwe PRODUCTION & CLIENT LIAISON MANAGER Antois-Leigh Botma 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 PRINTERS Novus Print KZN +27 (0)31 714 4700 ___________________________________________________

Dialogue is great, but implementation is essential

T

owards the end of January 2020, the International Monetar y Fund (IMF) released the findings of its latest Article IV Consultation with South Africa. Alongside primary engagement with government, the outcomes include consultation with key entities such as academia, business, organised labour and SOEs. The IMF continues to acknowledge South Africa’s potential to grow and prosper if it can get its house in order in core areas like public debt and re-establishing profitable SOE operations. These are not new observations, but they continue to emphasise the point from all parties, foreign and domestic, that things absolutely need to change.

No credible potential investor can stand by and not baulk at the prospects, given the glaring evidence of maladministration and worse.

The IMF’s forward view is conservatively optimistic.

That’s subject to the South African government continuing to implement reform measures that bring down the deficit and restore business confidence.

This will depend on an enabling and coherent policy framework.

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 2020. 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

More urgency needed Responding to the IMF report, National Treasury acknowledged the findings, commenting that “more urgency is required in the speed of implementation.”

Factoring in external economic factors beyond South Africa’s control, National Treasury states that a combination of government reform and private sector buy-in could see GDP growth of 1.7% by 2022.

That’s insufficient to meet our immediate infrastructure funding requirements, especially if we rely purely on public input. The taxation base is just too small and getting smaller. This means the real gains can only be achieved via capital inflows for listed investment vehicles that create a platform for bankable public-private partnership (PPP) opportunities.

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 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. _____________________________________________

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@infrastructure4

urenews.co.za

Infrastructure News

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

NT R E D E V E LO P M E

Roads & Bridge s e costing for

Lifecycl gravel routes

AINTENANCE • BUILDING • M

V E RY • S E RV I C E D E L I

Shisalanga Construction leader The sustainability in asphalt and roads

Water & Wastew ater NRW and water security

Cement & Concret Shaping the future

The ABC logo is a valued stamp of measurement and trust, providing accurate and comparable circulation figures that protect the way advertising is traded.

IMIESA is ABC audited and certified.

The National Water & Sanitation Masterplan, which requires hundreds of billions of rand to successfully implement, is a suitable PPP candidate. Government’s Integrated Resource Plan for future energy demand and delivery is another.

At the African Mining Indaba this month, captains of industry made it clear that South Africa’s energy crisis had reached the point where further investments would hinge on a very clear roadmap. In response, and as one of the proactive steps, South Africa’s Minister for Mineral Resources and Energy says plans are in place to make provision for mines to generate their own energy for self-use. This will follow the gazetting of a revision to the Electricity Regulation Act (No. 4 of 2006).

The way Eskom is re-engineered and right-sized is going to set the benchmark for all other SOE remediation programmes. If positively achieved, it will also have a profound influence on future governance.

There are still too many acting CEOs within the municipal, NGO and SOE space, and far too much political conflict. Public leaders have an exacting responsibility. These posts should be reserved for those deserving and dedicated to the task of putting their nation first as key socioeconomic enablers.

Among the foremost priorities are education (particularly in maths and science), employment, healthcare, social housing and sanitation.

We need action and results now, and that can only be achieved by open and proactive private and public sector participation.

We need a common vision and purpose.

Alastair INFRASTRUCTU

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

PPP candidates

e

with readymix

Geosyn thetics

life Extending reservoir

Cover opportunity

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.

IMIESA February 2020

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BIENNIAL PROJECT EXCELLENCE AWARDS

TUESDAY 27TH OCTOBER 2020 CAPE TOWN

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 13 JULY 2020

Only projects that have reached practical or substantive completion by 30 June 2020 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 SOUTHERNÂ AFRICA (IMESA)

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

PRESIDENT’S COMMENT

IMESA

A fresh look at water

A

cross South Africa, some dams are near full, but many are at a critical stage of depletion.

Across our borders, that includes the Katse and Mohale dams forming part of Phase I of the Lesotho Highlands Water Project (LHWP) constructed to deliver sustained supply to South Africa’s Gauteng region. As at the end of January 2020, Katse and Mohale were around 26.4% and 12.3% full, respectively.

From empirical evidence, this is a cyclical situation, but it highlights how sporadic rainfall patterns have become. This makes it challenging to forecast future scenarios based on our existing scientific data. Either way, extreme drought and flood events are becoming increasingly commonplace. A prime example is the famed Victoria Falls between Zambia and Zimbabwe, which has been

Randeer Kasserchun, president, IMESA

reduced to a trickle as the region experiences its worst drought in 100 years. Closer to home, that makes the completion of the Polihali Dam during Phase II of the LHWP even more essential as part of an intergovernment water strategy for medium- and longer-term water security.

The available sites for large dams in South Africa are mostly taken. We can raise existing walls and that has definite merit. However, a core part of our future resource planning must centre around the maintenance and upgrading of the current water storage and distribution network. The recently launched and highly comprehensive National Water & Sanitation Master Plan (NW&SMP) maps out the threats and proposed action points.

A widening supply and demand gap A quote from the plan underscores the urgency. It states, “If demand continues to grow at current levels, the deficit between water supply and demand could be between 2.7 and 3.8 billion m3/annum by 2030, a gap of about 17% of available surface [water] and groundwater.” The NW&SMP also says that an additional R33 billion is needed each year for the next 10 years to achieve water security.

Alongside a rising demand gap is an escalating rate of water losses due to pipeline and allied infrastructure failures. That’s bad news for the environment from a technical loss perspective. It is equally devastating from a non-revenue water (NRW) loss viewpoint.

According to the NW&SMP, municipalities are estimated to be losing 1 660 million m³/ annum in terms of NRW. That’s the equivalent of R9.9 billion lost annually (assuming a unit cost of R6/m³), which could have been billed

and ploughed back into asset management and new construction.

Another fact mentioned in the plan is that some 45% of South Africa’s water comes from rivers shared with neighbouring countries, which goes back to the point about co-managing the issues within our Southern African region.

NRW tool From IMESA’s standpoint, we are committed to working with our municipalities and to be part of the solution. In this edition, we have an article on a water conservation and water demand management (WC/WDM) tool developed by Emanti Management for application at local government level (see page 24). It was initially funded by Western Cape NGO GreenCape, with additional financial support provided by IMESA for the second of two pilot projects.

Many municipalities lack the capacity to develop bankable project proposals to access off-budget funding for NRW projects. Simplified, the goal of this is to enable municipalities to conduct a pre-feasibility assessment of their water business and their WC/WDM status. The data collected can then be used to mobilise support for NRW programmes from possible private and/or public funders.

However, municipalities need to know their NRW status first.

The tool’s roll-out has been backed by three initial IMESA regional municipal training workshops. The first two took place in Cape Town and Durban during Q4 2019. Our third workshop is scheduled for March 2020 in the Eastern Cape. The feedback received to date has been ver y positive and we’re excited about the practical evolution of the tool going for ward.

IMIESA February 2020

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COVER STORY

Environmentally conscious, innovative solutions from Shisalanga Leading the way in asphalt and road construction, what sets Shisalanga Construction apar t from the rest of their competitors is their drive to consistently deliver excellent products and ser vices, while pushing the boundaries of innovation.

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IMIESA February 2020

S

ince opening in Dundee, KwaZulu-Natal, in 1998, Shisalanga has continued to grow steadily. In addition to manufacturing and paving hot-mix asphalt, the road construction company also supplies a high-quality cold-mix asphalt.

EME, another Shisalanga product, is a high-modulus asphalt that is substantially stronger than standard asphalt and it is able to withstand high traffic exposure, allowing for a greater resistance to deterioration.

Shisalanga first made their mark as leaders in road construction with their steel slag aggregate – an unprecedented product for South Africa. Put to the test on the busiest highway in the country, steel slag is the preferred aggregate used in the manufacture of asphalt for the National Route 3 (N3).

Making use of waste products recycled from the steel industr y, steel slag manufactured asphalt forms the basis of

another Shisalanga product, Steel Flow.

This Ultra-thin Friction Course (UTFC) provides a more cost-efficient, ultra-thin paving application of 12 mm to 15 mm, versus the traditional 20 mm to 25 mm.

This process has assisted Shisalanga in establishing a strong foothold in the South African market.

Aside from the production of their recycled steel products, Shisalanga offers high-quality recycled asphalt (RA), which is manufactured by repurposing used and uplifted asphalt. This process successfully reuses up to 70% recycled asphalt that is mixed with 30% virgin asphalt mix, thereby reducing hazardous waste from the road construction industry.

Eco Asphalt Recently, Shisalanga has made an industryleading breakthrough in Africa by expanding their recycling possibilities to include recycled plastic waste, receiving acclaim

COVER STORY

for their world-class Eco Asphalt (patent pending). This innovative product is made from locally recycled HDPE plastic, which is used as part of a formula ingredient to create a unique binding agent.

In August 2019, the road construction company embarked on an ambitious initiative involving the paving of a South African road using Eco Asphalt. This makes Shisalanga the first South African company to successfully complete an application of recycled plastic road. This product provides a durable and sustainable solution for the road construction industry, while addressing the current abundance of plastic waste.

Milling, paving and hydrocutting Shisalanga is not only limited to manufacturing and supplying products for the asphalt industry. Part of their portfolio

also includes providing a variety of services such as the paving of hot- and cold-mix asphalt, base and tandem paving, laying of surface and slurry seals, crack sealing, in situ stabilising, deep and shallow milling, as well as hydro surface treatment.

Shisalanga has been growing from strength to strength in all capacities, with a speciality in hydrocutting. Their highpressure solutions enable the process of restoring texture and friction to a pavement surface via high-pressure water blasting.

Due to the removal of excess bitumen and rubber from the road surface during this process, skid resistance is increased, and accidents are more likely to be prevented on South African roads and runways.

Currently, Shisalanga has three highpressure hydrocutters in their selection of construction equipment. These machines fill a huge void in the road

industry with regard to surface texturing, rubber and spillage removal. An additional bonus is their low environmental impact.

They operate leaving a smaller carbon footprint compared to other methods, making the procedure exceptionally environmentally friendly.

Reaching new heights Shisalanga Construction consistently strives to do everything to the highest quality level, prioritising innovative solutions while being conscious of the impact on the environment. By upholding these ideals, the company has fostered a culture conducive to embarking on groundbreaking projects. Their drive to pursue cutting-edge technology and out-of-the-box procedures has enabled them to overcome challenges and reach new horizons in the road construction industry.

shisalanga.com

IMIESA February 2020

7

INFRASTRUCTURE NEWS

FROM AROUND THE CONTINENT

AFRICA Building a continental electricity network

AFRICA Resilience to extreme weather A group of international organisations has come together to assist developing countries to build resilience against the impact of natural disasters caused by extreme weather.

Following a series of deadly weather events that have caused widespread destruction, especially in Africa, the institutions came together at the COP 25 climate change conference in Madrid to launch the Alliance for Hydromet Development.

The science is clear: the global average temperature has increased by 1.1°C since the pre-industrial period, and by 0.2°C compared to 2011-2015,” said Petteri Taalas, secretary general, World Meteorological Organization.

“Ambitious climate action requires countries to be equipped with the most reliable warning systems and best available climate information services. Many developing countries are facing capacity constraints to provide these services. The Alliance is the vehicle to collectively scale up our support to the most vulnerable.”

The members of the Alliance have committed to ramping up action that strengthens the capacity of developing countries to deliver high-quality weather forecasts, early warning systems, hydrological and climate services. Known as ‘hydromet’ services, these underpin resilient development by protecting lives, property and livelihoods.

The African Development Bank (AfDB) has joined the Alliance in recognising the gap in the limited capacity of African countries to address vulnerability to extreme climate shocks and has committed to doubling its climate finance support to African countries.

The actions of the Alliance to close the hydromet capacity gap are guided by the principles of UN agreements, including the Sustainable Development Goals, the Paris Agreement on climate change and the Sendai Framework for Disaster Risk Reduction 2015-2030.

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IMIESA February 2020

The African Development Bank (AfDB) and the African Union Development Agency (AUDA-NEPAD) have agreed to jointly develop a blueprint for a pan-continental electricity network and market.

“The Continental Power System Master Plan will ensure that competitive electricity markets are developed at regional and continental levels, creating unique opportunities to optimally utilise Africa’s vast energy resources for the benefit of Africa,” said Professor Mosad Elmissiry, a senior energy advisor to AUDA-NEPAD’s CEO. The agreement to set up a Continental Power System Master Plan between the AfDB and AUDA-NEPAD was unveiled late last year during a three-day workshop in Cairo.

The workshop was aimed at advancing the launch of an Integrated Continental Transmission Network to link national power utilities into regional power pools and, ultimately, into a continent-wide transmission network. Plans also include setting up a market for electricity trading.

Development of a unified electricity transmission network and market for electricity trading are viewed as a critical priority to improve the lives of people across the continent.

“Most state-owned electric utilities in Africa today are unable to secure the financial resources needed to implement required segments of regional interconnectors and associated national feeder lines,” said Angela Nalikka, manager: National and Regional Power Systems, AfDB. “The Bank plans to encourage private sector participation in transmission projects in the continent.”

KENYA Helping Africa thrive

MALAWI Go for first solar One of Malawi’s first solar projects has reached financial close after attracting an investment volume of US$67 million (R970 million). Initial site works have begun in Nkhotakota, and construction of the first phase is targeted for completion by March 2020. Once complete, the project will add 46 MW of clean energy to the local power supply.

Developed by UAE-based Phanes Group in collaboration with responsAbility Renewable Energy Holding and the Overseas Private Investment Corporation (OPIC), the project was the result of the first power purchase agreement (PPA) signed with Malawi’s national utility (ESCOM) in February 2019. This was Malawi’s first competitive tender in the power sector, and the PPA is projected to last 20 years.

The Nkhotakota project is part of a push by the Malawian government to use solar power to strengthen the country’s electricity infrastructure.

Currently, only 15% of the population has access to power, and the national capacity is estimated at 362 MW. The new capacity added will make a significant contribution to the government’s target of increasing power access to 30% of the population by 2030.

The project will also move Malawi away from its traditional reliance on hydropower, which currently generates over 95% of the country’s energy capacity and leaves Malawi vulnerable to droughts.

During a recent trip to Kenya, Alok Sharma, the UK Secretary of State for International Development, pledged new British government aid to help build green cities across Africa with quality infrastructure.

Sharma announced that he would set up a UK Centre for Cities and Infrastructure, which will turbo-charge investment in fast-growing cities across the developing world. The centre will provide British expertise to African governments and city authorities to improve the way cities are planned, built and run, including making them more environmentally friendly. It will focus on improvements to infrastructure, including water and energy networks.

During his trip, Sharma also announced an expansion of the Department for International Development’s Cities and Infrastructure for Growth programme to Ghana, Rwanda and Sierra Leone. The programme helps UK businesses invest in quality, resilient infrastructure, boosts access to reliable and affordable power, and creates construction jobs.

“Our new UK aid support, announced ahead of the UK-Africa Investment Summit, will contribute to creating the African cities of the future, using British expertise to provide quality, green infrastructure across the continent.

“Infrastructure is the backbone of economic growth. It helps the poorest people access basic services such as clean water and electricity, creates jobs and boosts business,” said Sharma. He believes that the new UK aid will help build Africa's future cities, so the continent can continue to thrive and reach its economic potential.

“The continent’s urban population is 472 million and set to double over the next 25 years. This growth provides an opportunity for African cities to prosper if the right infrastructure and jobs are available with UK support.”

TANZANIA A new airport for Dodoma Tanzania plans to construct a new international airport in the capital Dodoma.

The airport will be built in the district of Msalato, 12 km from the capital.

The project involves the construction of high-capacity airport infrastructure to meet the expected growth in air transport from the city’s new role as the administrative capital of Tanzania.

Work will be carried out over four years and include a passenger terminal, runway and air navigation equipment. The project includes other related operational services such as a fuel distribution company, water supply systems, electrical power distribution substations and a fire-fighting service.

The new facility is expected to handle at least 50 000 aircraft and 1 million passengers per year, most of which will be international. It will benefit and serve more than 200 million passengers in East Africa, as well as international trade networks, and especially business travellers and tourists.

An expanded air transport network in Dodoma and the ongoing highspeed railway construction on the central corridor are considered necessary infrastructure investments to help unlock and disperse spatial development in the countryside.

IMIESA February 2020

9

ROADS & BRIDGES

Recycling pavements makes economic sense Resource depletion has led to the rapidly rising costs of aggregates derived from natural sources, but concrete pavement recycling can provide an economical and sustainable alternative.

This is according to Br yan Perrie, managing director of The Concrete Institute.

Bryan Perrie, managing director, The Concrete Institute

Forming a concrete road

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IMIESA February 2020

T

he recycling of concrete roads is a relatively simple process that involves breaking, removing and crushing hardened concrete from suitable sources to produce recycled concrete aggregate (RCA).

“Concrete pavements are 100% recyclable and such recycling has been extensively used in Europe since the 1940s and in the USA since the 1970s,” says Perrie. “In fact, concrete recycling for paving applications is now carried out in more than 40 American states, with production of RCA in the USA averaging well above 100 million tonnes.”

The main application of RCA has been as sub-base material, but it has also been used in concrete and asphalt concrete paving layers, high-value rip-rap, general fill and embankment, and other applications.

Perrie says a major incentive for concrete pavement recycling is cost savings. Aggregate costs for fill, foundation and sur face layers make up one of the highest costs of highway construction – between 20% and 30% according to a US study. Concrete pavement recycling saves some of these costs.

“The cost of producing RCA is confined to the costs of crushing the demolished concrete and screening and backhauling the RCA, coupled with quality control costs,” Perrie explains.

“The costs of concrete demolition, removal and hauling apply whether the pavement is

recycled or simply discarded; however, RCA production costs may be offset by savings in hauling and disposal costs, especially if the RCA is produced on-site. In South Africa, though, such recycling may require a waste licence.”

Green benefits Perrie says cost savings from concrete pavement recycling var y but have been reported to be as high as the US dollar equivalent of over R70 million on a single project in the USA. Furthermore, concrete pavement recycling is an environmentally sustainable option that: • conser ves natural aggregates and other resources • reduces unnecessar y consumption of limited landfill space • saves energy • reduces greenhouse gas emissions • captures carbon dioxide from the atmosphere.

RCA particles – which tend to be extremely angular – consist of reclaimed virgin aggregate, reclaimed mortar or both.

Reclaimed mortar generally has higher absorption, lower strength and lower abrasion resistance than most virgin aggregates. RCA, therefore, generally has lower specific gravity and higher absorption than virgin aggregate.

“The properties of a specific recycled concrete aggregate depend upon many factors, including the properties of the original concrete and the processes used to produce the RCA – particularly the crushing operations,” Perrie continues. “With proper process control, RCA can be produced to meet quality and grading requirements for almost any application and should be considered an engineered material for which the properties must be determined at the outset, so that appropriate mix design or construction adjustments can be made.”

With proper process control, RCA can be produced to meet quality and grading requirements for almost any application.”

New concrete mix factors When RCA is used in the production

ROADS & BRIDGES

ROAD COURSES IN 2020 The Concrete Institute’s School of Concrete Technology will present a one-day course in Concrete Road Design and Construction during 2020.

The training will be provided on 3 June in Cape Town, 19 August in Durban, and 7 October in Midrand. Contact sct@theconcreteinstitute.org.za or phone +27 (0)11 315 0300 for full details.

of new concrete mixtures, its effect on the properties of those mixtures can range from minimal to significant, depending upon the nature, composition and gradation of the RCA. “For example, when little reclaimed mortar is present in coarse RCA and virgin fine aggregate is used, the handling characteristics and engineering properties of the new concrete will be practically the same as if all virgin aggregate had been used,” he points out. “But if the new

Concrete pavements are 100% recyclable

mixture contains only coarse and fine RCA, these characteristics and properties will be substantially different from traditional concrete mixtures when all other mixture design factors remain constant.”

Perrie adds that recycled concrete aggregate has been used in the construction of hundreds of highway construction

projects in the USA and around the world in the past 50 years as pavement fill, foundation, sub-base and sur face courses for both asphalt and concrete. Successful projects range from relatively low-volume roads to some of the most heavily travelled highways, such as the Eden’s Expressway in Chicago.

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Engineering the Future now!

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ROADS & BRIDGES

The AfriSam advantage AfriSam offers a number of specially formulated materials for road construction.

IMIESA speaks to Amit Dawneerangen, GM: Readymix, AfriSam, about the company’s solutions.

What is AfriSam’s overall strategy for the roads market in 2020?

AD We will continue to support roadbuilding contractors with our quality, multiproduct offering, together with our reliable service and technical support.

This powerful combination helps ensure projects are successfully completed within deadline and to customers’ specifications.

Our roadstone – for asphalt and road surfacing – is supplied to the specific grading, shape and wearing properties required. For layer works, we supply aggregates for base and pavement (G1G3), as well as sub-base layers (G4-G6): different categories of graded material cater for varying load designs. Specialised

cement products such as Roadstab improve the stability of road materials.

We also serve the roads market with our cement and readymix concrete for ancillary infrastructure such as bridges, culverts and pavements.

Does AfriSam have specific solutions for stormwater systems?

Among AfriSam’s specialty readymix brands is Flowcrete, a highly workable, cohesive concrete that offers flexibility in both design and construction. Its raw materials and registered admixtures enhance fluidity without segregation occurring. It is ideal for complex shapes and congested areas in reinforced elements.

Many bridges across South Africa are ageing and require urgent remedial solutions. How can AfriSam assist in this regard?

AfriSam works closely with contractors engaging in various bridge-related contracts. We apply a range of fit-forpurpose cement and concrete solutions; our technical teams also collaborate with customers and engineers to design and test specialised concrete mix designs. For this application, high early-age concrete strengths are essential and AfriSam’s Rapid Hard and High Strength products are ideal.

Our expertise is enhanced by the research we conduct into the durability characteristics of concrete, which is relevant to concrete bridges. Our Durability Index Tests predict and prolong the life of these structures. Part of our research assesses the effects of highly corrosive environments on concretes, and how different proportions and types of raw materials can mitigate these impacts.

Amit Dawneerangen, GM: Readymix, AfriSam

Is the precast sector an important market?

AfriSam has long been a proactive partner to the precast industry, offering

value-added service through our Centre of Product Excellence. We develop specific products for companies in the precast market to ensure they benefit from optimal manufacturing processes.

Our product development team works closely with customers to develop and test products to suit particular specifications and applications, ensuring the long-term durability of structures.

Road aggregate selection is an exact science. Please expand on services in this area.

In addition to providing a range of aggregates to suit customers’ specifications, AfriSam also works with customers to select the correct aggregates in their particular region.

This includes taking various physical properties into account, as well as availability and climate. By actively mapping quarry rock type and quality, blasted material is expertly paired with customers’ applications. It is essential to understand the impact of properties such as gradation, toughness and water absorption.

What is the C-Tech advantage?

To enhance the performance and sustainability of our cement products, AfriSam has engineered C-Tech Composite Technology. Our composite cements use additives like pulverised fly ash, ground granulated blast furnace slag and limestone to partially replace cement. The result is a superior product to pure cement.

Apart from a reduced carbon footprint, these composite products also provide valuable technical benefits. These include improved workability with less water, reduced heat of hydration to minimise thermal cracking, and reduced susceptibility to chemical attack on steel rebar. They are also less permeable and thus more corrosion-resistant, and they continue to gain strength over time.

IMIESA February 2020

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ROADS & BRIDGES

Paving the way to an optimal road surfacing policy Road surfacing policy is among the most influential mechanisms available to road departments to alleviate budget and resource constraints and to enhance their level of public service delivery. Under specified conditions, sealing existing gravel roads is one of the most viable options. By Don Ross and Matthew Townshend

Professor Don Ross, UCT School of Economics

Matthew Townshend, economic consultant

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iven that gravel roads constitute 73.6% of South Africa’s road network, with approximately 84.3% of them carrying fewer than 100 vehicles per day, it is vital for efficiency that road departments first establish which roads are worth maintaining. They then need to adopt cost-effective surface solutions for these roads under the different local conditions across South Africa.

In the absence of a national road surfacing policy, road departments have based their strategy on the HDM-4 derived guideline that annual average daily traffic (AADT) must exceed 200 vehicles to justify upgrading an unsealed road to a surfaced standard.

However, many unsealed roads are only

upgraded to a surfaced standard once AADT exceeds 500 or 1 000 vehicles.

In contravention of this tradition is a trend that has been followed by at least 17 developing countries and investigated by five of South Africa’s nine provincial road departments. This is the trend towards surfacing unsealed roads irrespective of the traffic volume to eliminate regravelling and minimise the maintenance requirements over the life of a road.

FIGURE 1 Effective average spacing between operating borrow pits, January 2019

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IMIESA February 2020

Four factors common across South Africa, in addition to others, negatively affect the sustainability and cost-effectiveness of gravel road surfaces. First, the Department of Transport, Sanral and several subnational road departments are concerned that many areas lack sufficiently high-quality gravel materials for gravel road surfaces.

Resource and regulatory restrictions have led to a more uneven spread of borrow pits and longer haul distances. Figure 1 presents the Department of Mineral Resources’ January 2019 statistics for the number of operating mines that produce gravel materials for road surfacing. The shortest effective average spacing between borrow pits is 14.8 km in Gauteng province, with this distance rising to 113.4 km in the Northern Cape.

The Northern Cape Department of Roads and Public Works links excessive haul distances to the fact that gravel deposits in many areas are non-existent, on inaccessible land or exhausted.

ROADS & BRIDGES

Given that gravel roads constitute 73.6% of South Africa’s road network, with approximately 84.3% of them carrying fewer than 100 vehicles per day, it is vital for efficiency that road departments first establish which roads are worth maintaining

Erosion factors Second, gravel road quality and maintenance costs are highly sensitive to environmental factors such as steep road gradients and high moisture levels. The erosion of gravel road surfaces on steep gradients can be reduced by improving the shear strength of the wearing layer through adequate compaction, grading and gravel size. It is also possible to remove the bulk of the rainwater from the road surface before it erodes the gravel wearing layer or infiltrates the pavement structure.

This can be achieved through better drainage and frequent road maintenance to ensure the road has a compact, tightly bound wearing course, a definite crown, adequate cross-fall, and no potholes, corrugations or ruts. However, all of these works escalate the relative cost of gravel road provision, which leads to the conclusion in the

Technical Recommendations for Highways (TRH 20) manual that it is not cost-effective to avoid erosion on sections of gravel road with steep gradients or high moisture levels.

Third, because gravel loss is a function of road traffic, climate conditions and material properties, many gravel roads across South Africa experience high annual rates of gravel loss. For example, average annual gravel loss for some roads in the Western Cape province is between 25 mm to 50 mm, with extreme cases reaching 255 mm. Average annual gravel loss in KwaZulu-Natal province varies between 5 mm and 75 mm. Regravelling cycles can therefore shrink from the expected 7 to 10 years to as short as five months.

Fourth, a policy to seal gravel roads with a light bituminous seal using labour-intensive practices could generate up to 7.1 million full-time equivalent (FTE) work opportunities.

Importantly, most of the jobs would be low-skilled and located in predominantly rural provinces with the highest levels of unemployment. Figure 2 apportions the total FTE work opportunities equally across years according to possible 5-, 10-, 15- and 20-year timeframes over which authorities may seal gravel roads. The data demonstrates that sealing all proclaimed gravel roads over a 20-year period could generate approximately 356 035 additional FTE jobs per annum and reduce the national unemployment rate by 1.6% over the period. In the context of a 27.1% unemployment rate in Q4 2018, a policy to seal those gravel roads worth maintaining at all would contribute significantly to lowering unemployment.

Life-cycle cost analysis and recommendations

FIGURE 2 Annualised additional FTE job opportunities from sealing gravel roads at different rates

Given the international trend towards sealing low-volume gravel roads and the prevalence of many factors that increase the relative cost of gravel road surfaces, a life-cycle cost analysis (LCCA) was conducted. The LCCA compared the whole-life cost of three lowvolume road categories: new gravel and lightly sealed roads; existing gravel roads in good condition; and existing gravel roads in poor condition. The reviewed costs cover both conventional and alternative pavement

IMIESA February 2020

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ROADS & BRIDGES

designs and include all differential planning, design, construction, routine and periodic maintenance, rehabilitation, and salvage costs.

The LCCA results were presented at the 2019 Conference on Asphalt Pavements in Southern Africa and discussed further in workshop sessions. Essentially, the study supports the following four dominant policy recommendations, which await follow-up by the provincial road departments and the National Department of Transport.

Policy recommendation 1: If a traditional pavement design is required to support a lightly sealed but not a gravel road surface, then it is cost-effective to maintain gravel roads irrespective of their initial condition.

However, because the TRH 20 Simplified Design Catalogue specifies the same pavement structure for low-volume gravel and lightly sealed roads, this recommendation does not apply to new roads. Moreover, this recommendation applies to a low proportion of existing unsealed roads.

Based on the longstanding principle in TRH 20 that good preparation of the subgrade is important, as this should form the subgrade for future improved roads, the minimum subgrades that have been specified for gravel roads are relatively strong. Given the strength of the specified subgrade designs, trafficinduced compaction of the subgrades over the life of unsealed roads, and the fact that many regions in South Africa possess strong in situ materials, the in situ materials on most

South Africa

of the 454 609 km of existing unsealed roads should provide a strong enough pavement structure to support lightly sealed roads.

Policy conclusions The following three recommendations are thus the main policy conclusions.

Policy recommendation 2: Wherever the in situ subgrade has sufficient bearing strength to support expected traffic volumes without structural upgrading, it is cost-effective to seal gravel roads in poor and very poor condition. This finding potentially applies to the 352 301 km of gravel road, or 77.5% of the proclaimed gravel road network, in poor and very poor condition in 2017. Moreover, it is cost-effective to seal unproclaimed gravel roads in areas with good in situ subgrade if proclaimed.

Policy recommendation 3: Wherever the in situ subgrade has sufficient bearing strength to support expected traffic volumes without structural upgrading, it is cost-effective to seal many gravel roads in good condition. This finding potentially applies to the 31 319 km of gravel road, which is only 6.9% of the proclaimed gravel road network, in good and very good condition in 2017. Given that departments have tended to maintain highervolume gravel roads in better condition, it is likely that most of these roads will fall within the stress test combinations that render seals more cost-effective than gravel.

Policy recommendation 4: New roads should be sealed except under conditions ideal for

gravel road provision. The R186.6 million that provincial road authorities spent to construct gravel rather than sealed roads between 2013/14 and 2015/16 could lead to as much as a R6 million premium per km over a 30-year period. A policy to seal new roads presents road authorities, who face severe funding constraints, with an opportunity to realise significant future budget savings.

Human capital considerations There is near-unanimity among economists that South Africa’s most urgent policy priority is improving the quality and extending the distribution of lower-skilled human capital that has a non-negative shadow value.

Such assessment should be done in terms of welfare, not monetary value. However, there is no meaningful room for doubting that in South Africa, if policy A dominates or ties with policy B in terms of expected monetary value, but A contributes more to the human capital stock among citizens with relatively low levels of formal education, then A dominates B with respect to optimising public utility.

This analysis indicates that choosing sealed surfaces over gravel surfaces is an ‘A-type’ policy where the overwhelming majority of real road surfacing decisions are concerned. Because a policy to seal gravel roads is the dominant strategy, the road departments should begin sealing gravel roads worth maintaining at a rate possible within budget limits.

ROADS & BRIDGES

Mogale City teaches learners road safety

Following its official launch, the newly renovated Mogale City Junior Traffic Training Centre (JTTC) in the West Rand is providing a safe space for children to learn about road safety.

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he JTTC will provide small-scale simulated road environments where Mogale City traffic officers can teach primary school learners good road safety habits.

According to Saied Solomons, president, South African Road Federation (SARF), road safety is a critical problem in South Africa and a large percentage of fatal crashes include pedestrians that are children. “Children have different mental and physical characteristics that limit their ability to handle complex traffic situations. We need to educate children – learners in schools – about road safety. Too many of our JTTCs in South Africa are now derelict and unusable,” he says.

Revitalising the JTTC During discussions between SARF and the Mogale City’s Department of Public Safety, it was discovered that the municipality had an old Junior Traffic Training Centre (JTTC) that had not been used for many years. Basil Jonsson, operations director, SARF, rallied support from the SARF Northern Region members to renovate and reopen the JTTC. The municipality cut the tall grass and

removed 22 large tree stumps on the JTTC premises, as well as repaired a water seepage problem.

SARF and its members then stepped in and assisted by supplying hot-mix asphalt, repaving all the roads at the JTTC and installing kerbs. They also manufactured and supplied all the traffic signs and special plastic poles, as well as road-marking paint.

Fencing was erected around the JTTC, which was also repainted, and 16 wire cars were also donated for children to use as part of the learning process.

“We would like to thank all of our members who contributed to the Mogale City JTTC and, ultimately, to child safety in the city. Without them, we could not have made this a reality,” said Jonsson.

Working together Speaking at the JTTC launch, Ashmar Khuduge, executive manager: Community Development Services, Mogale City, thanked Jonsson and SARF, noting that the public and private sectors need to work together and share the responsibility for establishing infrastructure that will facilitate development.

Khuduge believes that Mogale City has demonstrated good governance and assured SARF that the new infrastructure is in good hands and will be taken care of. “We want to commit. From a human resources perspective, it will be used,” he stressed.

He assured that the JTTC will be properly maintained and Mogale City will regularly report on the outcomes of SARF’s investment.

“This effort will go a long way to save lives because we will educate our kids,” he said. The JTTC will also be used to educate adults without drivers’ licences on road laws and safety.

“We have agreed that we have a responsibility to reach out, as government, because we want our roads to be safe,” concluded Khuduge.

IMIESA February 2020

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ROADS & BRIDGES

Waterfront bridge swings into action The V&A’s new swing bridge being lowered into position

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ince opening in mid-2019, the V&A Waterfront’s new, improved swing bridge has provided safe transit for hundreds of thousands of pedestrians transiting between the Alfred and Victoria basins.

It replaced an older swing bridge installed in 1997 that was struggling to keep pace with rising foot traffic. Prior to that, this section of water was traversed for decades by the so-called Penny Ferry, a simple rowing boat that plied back and forth with its small group of passengers.

On the water and being towed to the site

SMEC South Africa was engaged by V&A Waterfront Holdings as the lead design firm and structural engineer, working in conjunction with COA Architects and Eadon Consulting. SMEC delivered various typological options for the new link, and a swing bridge was again considered the best solution in terms of the time and electrical energy needed to operate it.

The new 42 m long structure matches its predecessor’s opening and closing timeframes, but the deck is significantly wider, measuring 4.5 m, compared to the original’s 2.5 m. The lower part of

A bird’s-eye view with the new swing bridge in operation

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IMIESA February 2020

the new deck is a steel girder framework bolted to a 0.5 m wide central steel spine beam. The latter protrudes 470 mm above most of the length of the upper part of the deck, which is made of timber. The spine beam and 14.5 m tall mast, angled at 20 degrees from the vertical, are both fabricated steelwork and are bolted together at the pivot point.

An elegant structure, the V&A’s new bridge is capable of operating in wind speeds of up to 60 km/h with infinite headroom when open to passing ships.

A 26 t precast beam being transported to the site of the N4 Crocodile River bridge dual carriageway extension

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A precast element being swung into position

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N4 upgrade on track

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he Bakwena Platinum Corridor Concessionaire (Bakwena) confirms that the upgrades along the N4 Bakwena route are on track. Continuous maintenance, rehabilitation and upgrades are necessary to ensure the N1-N4 route meets the highest international standards for toll road operations.

The current upgrades include the addition of a 32 km long dual carriageway on the N4 between the M17 and R512 (Brits Interchange).

Part of this upgrade also includes additions and extensions to five existing bridges crossing sections of the N4.

Recent developments include the dualling of the N4 bridge that crosses the Crocodile River. This bridge has five spans, each consisting of 10 precast reinforced concrete beams. Each beam weighs 26 t and is individually transported and then lifted on to the bridge piers. The expected completion date for the dualling of the bridge is March 2020.

Solomon Kganyago, commercial manager, Bakwena, says the project cost of the current N4 upgrade is around R582 million, with a 36-month construction timeframe. All works are scheduled to be completed in June 2021.

“The addition of the carriageway will enhance the driving experience of motorists and improve their overall safety on the route,” concludes Kganyago.

INFORMATION TECHNOLOGY

Real-time control keeps projects on track The construction sector is one of the least digitised industries in South Africa and across the globe.

While this is largely attributed to the complexity of the industry, the power of data can no longer be ignored, writes Andrew Skudder.

D

igital adoption in construction has been low, with the industry spending, on average, between 1% and 1.5% of turnover on information technology, compared to about 3% across all industries and between 5% and 10% for more sophisticated industries, such as banking.

There are various reasons for this. First, construction is a highly complex sector with several stakeholders involved in the various projects. Collaboration among the stakeholders, from the client and main contractor, to all the subcontractors, can be complicated. Second, it’s a project-by-project business and stakeholders and business processes differ from one project to the next.

As a first step, construction companies need to digitise their core business processes.

Investing in the right software will help them run their businesses more effectively.

The solutions they choose need to provide real-time information to help them make informed decisions in areas such as estimating, project control, cost and enterprise management. This will help them improve controls, compliance, efficiencies and contribute positively to the bottom line for each project.

Andrew Skudder, CEO, Construction Computer Software

Research by the McKinsey Global Institute shows that the digitisation of the engineering and construction industry can lead to productivity gains of as much as 14% to 15% and cost reductions of between 4% and 6%.

Technology tools Drones can be used for pre-construction site surveys, as well as during construction to check build progress. Wearables such as virtual reality glasses can be used to visualise the designs of the structure while under construction. In addition, computer vision technology can be used to track external progress on construction sites, as well as to alert foremen or site agents to unsafe work behaviour or safety hazards on-site.

One of greatest issues in the industry is the commencement of construction before the design is finalised and the true programme has been determined to the nth degree. This often has time and cost implications when changes in design or the construction programme lead to escalation.

Here, the harnessing of 5D building information modelling is critical. It helps establish how long a project will take and how much it will cost at each phase, depending on different designs, methods, building materials and fittings. The more work that is concluded

up front to simulate the construction and iron out all the issues, the smoother the real construction will be.

The importance of using technology to track resources, labour, equipment and material utilisation on-site cannot be underestimated.

It helps generate data that can be used to identify trends, inform decisions, and enhance productivity on existing and future projects.

Cloud platforms Ultimately, all construction technologies need to be integrated via a vertical cloud platform.

This will see all data being fed into one place, whether through traditional ERP-type solutions, project control solutions, artificial intelligence or the internet of things.

Instead of chasing down quotes from three different suppliers and conducting a manual comparison of costs and quality, estimators can use software to do the job faster and more efficiently. By removing the grunt work from estimators, they’re able to spend more time finding solutions to strategic issues relating to a project.

Ultimately, the ability to take data from conception through to operation really is where a fundamental change needs to occur. This will enhance productivity at every stage of the construction process.

IMIESA February 2020

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MUNICIPAL FOCUS | MIDVAAL

Working for the people

Executive Mayor Bongani Baloyi

Last year, Midvaal Local Municipality was named the only municipality in Gauteng that achieved a clean audit, securing it a clean audit award and the most stable municipality award from the South African Local Government Association (Salga).

T

he clean audit award is given to municipalities and public entities that received an unqualified audit with no other findings for the financial year. The audit outcome confirms that the municipality’s financials are reliable, compliant and on par with legislation and reporting performance standards.

“Clean audits are a standard to uphold but don’t mean anything if they do not translate into a tangible difference in our residents’ lives. We are committed in ensuring that the welfare of the people of Midvaal is not compromised and delivery is in our priority list,” said Executive Mayor Bongani Baloyi.

In his most recent State of the Municipality Address, Baloyi noted that the current administration strives to achieve more than just a clean audit, by improving the lives of the city’s people and aiming for efficient service delivery.

“I made this demand being fully cognisant of the sheer hard work it takes to have achieved five clean consecutive audits, as confirmed by the Auditor General,” he said.

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IMIESA February 2020

In addition to the awards from Salga, Midvaal also received the Diamond Arrow Award at the PMR.africa 2019 Awards as the municipality doing the most for: • job creation • social upliftment • cleaning the environment • fighting crime • attracting local and foreign investment • developing and enhancing infrastructure.

In highlighting Midvaal’s commitment to service delivery, Baloyi reported many positive developments in maintenance and service delivery.

Housing Through its Human Settlement Plan adopted in 2017, the municipality is currently facilitating housing delivery for the Sicelo Erf 78 Meyerton and Sicelo Erf 204 farms, Savanna City and Mamello Extension 1.

The Sicelo Erf 204 Meyerton farms project has seen the completion of 259 houses, which are being transferred to beneficiaries. The Sicelo Erf 78 project will see the construction

of 700 walk-up units. These will assist in the eradication of informal households in the Sicelo informal settlements.

Waste management Illegal dumping remains a challenge among some of Midvaal’s poorer communities.

Following the municipality’s agreement of support with the City of Johannesburg, Midvaal is piloting its own clean-up campaign based on Johannesburg’s A Re Sebetseng and Rwanda’s Umuganda models.

The municipality has also embarked on a mission to reach zero waste to landfill. The first step in this process is separating all green waste at transfer stations and making that available for composting.

“The opportunity for Midvaal Municipality to claim its rightful space in the green economy is here. The space for our residents to drive green initiatives, which drive innovation and employment opportunities, is now,” said Baloyi.

Electricity Midvaal has undertaken feasibility studies and set up a concession framework for an electricity distribution services public-private partnership (PPP). The municipality is now in the process of procuring a PPP in the form of a concession for the finance, design, management, operation and maintenance of an electricity distribution network and the associated provision of the electricity distribution services currently undertaken by the municipality.

MUNICIPAL FOCUS | MIDVAAL

Clean audits are a standard to uphold but don’t mean anything if they do not translate into a tangible difference in our residents’ lives. We are committed in ensuring that the welfare of the people of Midvaal is not compromised and delivery is in our priority list.”

“PPPs have proven to be the best model for efficient, standardised service delivery as well as running an open, transparent and responsive government,” said Baloyi.

Procurement Baloyi called for the municipality’s current procurement policies to be reviewed based on competition and balance. This would see the formulation of a procurement transformation policy that will: • target previously disadvantaged or designated groups in line with preferential procurement regulations • improve the grading status of contractors in

targeted categories and grades • increase the number of black-woman-, disabled- and youth-owned companies in targeted categories • create sustainable contracting enterprises by enabling continuous work through a competitive process.

Budgeting Baloyi noted that ongoing difficulties in the national and local economy, including limited growth, have become evident in the local economy. It is, therefore, vital to be proactive and not waste resources on mistakes that could easily be avoidable through applying sound

fiscal, financial and revenue management. In the 2019/20 financial year, Midvaal committed to spend its capital expenditure on infrastructure services, allocating 73% of the capital budget to the Engineering Services Department.

“With an increase of 8.4% in operational expenditure from the previous year, this means we will spend as much as R122 million on much-needed repairs and maintenance of our infrastructure.

“Midvaal Municipality is reprioritising projects and expenditure within the existing resource envelope given the cash flow realities and the increased cost of bulk water and electricity,” he said.

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WATER & WASTEWATER

A practical tool addresses water security issues Extended drought conditions and rising populations are placing major pressure on water utilities and municipalities, making water conservation and demand management a critical activity. IMIESA speaks to Philip de Souza from Emanti Management about a new tool the company has developed to help fund and execute the process.

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s dam levels drop across South Africa, water restrictions have become a way of life and urgent solutions are required to balance socioeconomic growth alongside the preservation of surface water and groundwater resources.

Within this mix, non-revenue water (NRW) is a significant problem for many municipalities. NRW impacts negatively on the ability of municipalities to fund and execute water and sanitation infrastructure projects.

South Africa has an average national NRW of approximately 41%, with an average per capita consumption of approximately 237 litres (DWS, 2018). Halving

current water losses nationally could equate to approximately R6 billion, considering a production cost of R7.60/kℓ, and excluding additional income from improved metering and billing, deferred capital costs and electricity savings (DWS, 2018). Clearly, there is definite scope for improvement.

NRW challenges However, although NRW reduction projects can have short payback periods (typically three or four years), significant barriers to developing these projects often exist at municipalities. These include: • municipal capacity to develop bankable project proposals to access off-budget funding for NRW projects, and a lack of on-budget funds • awareness of the potential for NRW projects and their impact on municipal revenue • lack of political will to prioritise NRW projects or their feasibility studies • compliance and enforcement capabilities of authorities tasked to reduce water losses.

In order to address some of these barriers,

a project was initiated by Western Cape NGO GreenCape, to assist municipalities in developing a pre-feasibility assessment of their water business and water conservation and demand management status. The goal was to highlight the potential opportunities that an NRW programme could have for financial outcomes. Such an assessment would then be used to mobilise support for NRW programmes from possible funders, as well as within the municipal political and financial leadership structure.

Together, Emanti and GreenCape assisted Laingsburg, a typical small municipality in need of support with the implementation of water conservation (WC) and water demand management (WDM) strategies. The objective was to develop an easy-to-use WC/WDM prefeasibility assessment tool app that would then have a broader application across all South African municipalities.

“We researched international and local literature to identify best practice examples and used this to develop appropriate algorithms for the model,” says De Souza.

“The primary focus was to investigate how utilities/municipalities had been able to achieve water volume savings and how this then translates in terms of project financing.

A critical factor in ensuring a meaningful tool output is the quality of the data input, given the age-old mantra that ‘garbage in is garbage out’.”

IMESA funding IMESA provided additional funds to further

WATER & WASTEWATER enhance and modify the tool based on outcomes from the Laingsburg pilot, and feedback from key sector stakeholders. This led to a second-phase tool refinement study at Stellenbosch Municipality. The application of the tool was well received, confirming Stellenbosch’s own current status (NRW of around 20%, which is among the best nationally) while providing an indication of opportunities for further performance improvement and refinement of their current approach.

The current tool is now ready for further use and implementation, with the roll-out backed by three IMESA regional municipal training workshops. The first two took place in Cape Town and Durban during October and November 2019, respectively. The third workshop is scheduled for March 2020 in the Eastern Cape.

“The major benefit of the tool is its simplicity, assuming that the persons collecting and capturing the data have a working understanding of water supply systems and their components, and the compelling ‘dashboard’ nature of the outputs for decision-makers,” De Souza explains.

As is standard practice in local and international industry, the expert knowledge of a specialist consulting engineering firm remains important in providing advice through the pre-feasibility, feasibility and project implementation phases.

“By way of example, and using a simplified scenario, the model might calculate that if R1 million were spent on an NRW project, the predicted savings achieved would be 100 000 kilolitres per annum. If one kilolitre costs R10, then R1 million would be saved, implying a payback period of one year. In year two, the municipality should continue

NON-REVENUE WATER PRE-FEASIBILITY TOOL 1 Basic inputs 2 Current status 3 What is my WC/WDM strategy?

WC/WDM interventions 4 What could I consider?

5 Updated status these interventions make 6 Do financial sense?

7 Useful resources

to reap savings, Input Data with potentially no additional capital costs and perhaps some Current Performance equipment operation and maintenance Develop costs,” he continues.

Strategy “The tool repeats these calculations Input across a host of NRWInterventions related interventions, and this then provides Performance the star ting point Impact for fur ther funding discussions presented Financial by the municipality’s Viability management team and/or sector funders,” he adds.

As an added advantage, the tool will assist in addressing municipal asset register management, which is a critical shortfall pointed out by the Auditor General South Africa on recent and past audits. If it can’t be measured, it can’t be managed. To accurately use the tool, municipalities must have up-to-date asset management systems.

One of the tool’s default data field inputs, for example, is a high-level age analysis of municipal meters in use.

“The ultimate objective is to work with IMESA and sector role players to ensure that the tool is accepted and applied by all municipalities, thereby assisting with enhancing WC/WDM planning and improved performance management throughout South Africa. Collated information could then be pooled into a national statistical database that could be extremely useful to the National Water & Sanitation Masterplan and current drought relief efforts,” says De Souza.

“A clearer view of prioritised interventions that address NRW challenges nationally

• System characteristics, water, finance, energy/carbon tax and human resources • Water balance • NRW%, water use efficiency, infrastructure leakage index, tariffs • Determine the targets for the WC/WDM strategy • Propose interventions (e.g. fix pipes or replace meters) with budget • Check how interventions impact on performance targets • Does the WC/WDM strategy make financial sense?

• Which interventions provide the best returns?

Workshop in KwaZulu-Natal, 15 November 2019: IMESA members completing the training exercise

would then serve as a motivation for larger-scale public-private par tnership funding mechanisms, based on a high degree of certainty on investment returns,” De Souza concludes.

For fur ther information, please contact Philip de Souza at Emanti (+27 (0)21 880 2932) or Ingrid Botton at IMESA (+27 (0)31 266 3263).

COMPLETE SCENARIOS – INTERVENTIONS

IMIESA February 2020

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WATER & WASTEWATER

Good governance needs capacity Government’s focus on demand management and new infrastructure will not address the key issues affecting water services in South Africa if underlying problems like corruption, procurement bottlenecks and skills gaps are ignored.

By Neil MacLeod*

F

ollowing the release of the National Water and Sanitation Master Plan, media reports quoted Minister Lindiwe Sisulu and other government spokespersons placing an emphasis on the reduction of water demand, and the construction of new water infrastructure, as the solutions to South Africa’s critical water situation.

In my view, this emphasis is misplaced and does not address the key issues that require resolution.

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IMIESA February 2020

The provision of water and sanitation services is largely a municipal function, and the cash flow required to underpin the provision of these services comes primarily from customers in municipalities. It is true that national government is responsible for the construction of large dams and the supply of treated water by water boards; however, the rest of the value chain is located within municipalities and that is where we should be focusing our efforts.

Dealing with corruption in local government My many years of working in and with municipalities across the world have taught me that legislation in itself will not address corruption. Secrecy is the enemy of good governance.

Corruption should be addressed by prohibiting any convergence of the powers of those responsible for policy and tariffs and those responsible for executive management.

Legislation should: • prohibit any municipal official from being an office-bearer in a political party (be it at a branch, regional, provincial or national level) • introduce stiff penalties for any individual councillor found giving instructions to an official

• r esult in the removal of any official or councillor found to be involved in processes that undermine council resolutions.

The latter include demanding the appointment of specific persons, insisting on the awarding of contracts to certain companies outside the legal process, and failing to take action against anyone not paying for municipal ser vices. The sanction should be removal from office with no ability to work in or for any municipality for three to five years at least.

I believe there also needs to be a cooling-off period between a municipal employee becoming a councillor or a councillor becoming an employee of a municipality. The contribution of the executive mayor system to the rampant corruption in municipalities should also be investigated.

Furthermore, there should be an independent body that can investigate corruption in municipalities and be capable of offering advice to anyone needing assistance in dealing with and reporting it. The system used must protect the whistle-blower and also ensure that malicious allegations are dealt with severely.

WATER & WASTEWATER

Counterintuitive regulations and processes The National Treasury regulation that intended to compel successful tenderers to subcontract 30% of infrastructure contracts over R30 million has also been poorly communicated. In some instances, this has led to communities and organised gangs invading construction sites demanding a share of the work or a cash payout in lieu of this.

The restrictive National Treasury supply chain regulations have further made the awarding of contracts efficiently and at a fair price virtually impossible. In fact, it is clear to me that all these regulations merely sanitise corruption, result in inflated prices and excessively lengthen the procurement process, sometimes by up to a year.

In addition, these regulations and section 78 of the Municipal Systems Act (No. 32 of 2000) make the use of public-private partnerships (PPPs) as a way of transforming local government service delivery and developing capacity in municipalities equally impossible. The regulations need drastic revision if communities are to receive the levels of service they deserve. The PPP unit in National Treasury should be transformed to support and encourage a wave of PPPs in municipalities.

The Municipal Infrastructure Investment Unit established near the beginning of the Mandela presidency is a good example to follow. It was able to successfully execute more than 160 deals and partnerships with the private sector over its six-year life and create a library of support documentation to be used by municipalities.

The municipal skills gap and service delivery Research by Dr Allyson Lawless for her book Numbers and Needs in Local Government showed that engineering professionals do not want to work in municipalities.

The reasons include weak management;

political interference in technical matters, procurement and staff appointments; as well as rampant corruption.

As a result, there are more than 200 municipalities that do not have any engineers on their staff and about 30 municipalities employ no engineers, engineering technologists or technicians.

It would be like a hospital saying, “We do not have any doctors or surgeons, but our paramedics and nurses will cope!”

As a result of the demographic transformation in municipal technical departments, the institutional memory in municipalities has been lost and very few older and experienced engineering professionals remain to mentor the younger ones. The majority of engineering professionals in municipalities are now under the age of 40.

To address this, a detailed training programme was developed by government some 10 years ago but has never progressed beyond the concept stage and now needs to be revisited. Based on a block release approach over a two-year period, the plan was to train around 500 existing and aspirate directors of technical services in municipalities. Passing the course should be a prerequisite for any person wanting to be appointed to an executive position in a municipal technical department.

Five essential components There have been numerous unsuccessful attempts to address poor service delivery in municipalities. We have seen Project Consolidate, Siyenza Manje, Back to Basics, MISA, etc. all fail because they do not address all five components of successful service delivery listed below. Most only focused on the last aspect: • customer management • revenue management • human resources management • asset management • new infrastructure delivery management.

The national ministr y responsible for water and sanitation is in a state of crisis by its own admission, as are more than 70% of the municipalities responsible for the provision of basic infrastructure ser vices, according to the Auditor General, so there is a need to develop capacity before there can be any coordination.

In our cities and towns, the municipality is in the top 10 organisations, and often the largest one, based on the number of employees or billed revenue, yet it is administered by a ‘board’ of councillors with little business expertise. Some municipal councils reportedly have an average level of education of grade 10. These councillors are expected to exercise oversight over municipalities that have budgets ranging from hundreds of millions to the billions. Clearly, Cogta and Salga have not succeeded in preparing councillors adequately for their roles.

At the other end of the scale, we have a need for about 30 000 skilled artisans and 30 000 competent treatment plant operators in our municipalities. A decision was taken years ago by the SETAs to abandon apprenticeships and replace them with learnerships. It didn’t work – a case in point being the R1 billion War on Leaks programme to train plumbers. We need to return to skills-based apprentice training supported by classroom learning.

There are solutions to all these issues – it all just needs the right leadership and skills in place to drive the process and ensure that municipalities function as well-oiled and financially sound ser vice deliver y businesses. To achieve this, we need to deal with corruption, as well as the policy and regulator y framework that is hampering ser vice deliver y and effective oversight. *Now retired, Neil MacLeod is the former head of eThekwini Water & Sanitation.

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WATER & WASTEWATER

Addressing unpredictable feedwater quality The Cape Town International Convention Centre (CTICC) has installed two boreholes to use as an alternative supply of water. However, the highly unpredictable nature of the feedwater quality has proven a challenge. By Nico-Ben Janse van Rensburg*

T

he CTICC is situated on reclaimed land and parts of the building sit below mean sea level. It was, therefore, expected that seawater ingress would result in near-seawater quality from the boreholes, and a desalination plant to treat seawater at 31 000 mg/ℓ TDS (total dissolved solids) was constructed.

Upon testing the boreholes in November 2018, it was found that the water also contains extremely high levels of iron and

9000

Borehole Iron

8000

Iron g/l

7000

6000

5000

4000

3000 2018-11-01

2019-05-10

FIGURE 1 Iron grab samples

10000

Manganese

9000

Manganese g/l

8000

manganese. The boreholes were tested for the full SANS 241:2015 list and it was found that borehole 1 contains 4 475 µg/ℓ iron and 6 850 µg/ℓ manganese. Borehole 2 contains 4 575 µg/ℓ iron and 6 650 µg/ℓ manganese.

Prior to commissioning the desalination plant, extra pre-treatment steps had to be installed.

The pre-treatment consists of oxidising the iron and manganese at high pH, clarification and filtering the overflow from the clarifier through a Maddox filter.

The plant was commissioned mid-March 2019 and started fullBorehole 1 Borehole 2 time test production in April, initially operating as a well-designed reverse osmosis (RO) plant should.

The drift in normalised flux or increase in differential pressure was observed until a rapid change in midAugust. The 100 µm bagfilter used as a strainer prior to ultrafiltration 2019-09-18 (UF) began blocking rapidly. The UF requires frequent CIP (clean-inplace) procedures and the RO is steadily building Borehole 1 differential pressure Borehole 2 and normalised flux is declining.

7000

Grab samples

6000 5000 4000 3000 2018-11-01

2019-05-10

FIGURE 2 Manganese grab samples

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IMIESA February 2020

2019-09-18

On 10 May, another grab sample was taken, and it was noted that the iron and manganese levels had drastically increased. The effect was noticed on the rapid build-up of deposits on the 100 µm bag filter

used as a screen prior to the UF as well as the necessity to CIP the UF. The pre-treatment was upgraded to dose sodium hypochlorite to act as an oxidant. The free chlorine is then neutralised by sodium metabisulfite prior to the RO system.

Figures 1 and 2 show the iron and manganese levels in the two boreholes, respectively, as measured by an independent laboratory. Typically, a line graph would not be ideal for this type of data, but the graph aims to show the irregular levels of iron and manganese in the feedwater. It is suspected that the borehole water quality is highly dependent on seawater ingress, which is tidal in nature.

After the test period and attaining the required agreements to use this alternative source, full-time operation started in June 2019. Figure 3 shows iron and manganese build-up in the borehole receiving tank after two months of operation.

Effect on UF and RO No unusual issues were experienced during the initial operation of the plant. However, it became apparent that the CIP frequency was increasing while, at the same time, normalised flux and rejection started to show increased rates of decline.

Figure 4 shows the performance of the RO, where the normalised product flow and normalised permeate TDS as calculated from inline measured conductivity is overplayed in red.

Important to note from Figure 4 is that the initial data to the left of the graph shows the normalised product flow to be higher than the actual flow, and the normalised product TDS to be lower than the actual TDS. This is typical behaviour for new membranes; however, at this point, the membranes have been operating for over two months

WATER & WASTEWATER

(m 3 /h)

10 8 6 4 2 185 180 175 170 165 160 155 150 60 55 50 45 40 35 30

20 19 -0 702 20 06 19 :0 -0 0 70 6 20 06 19 :0 -0 0 710 20 06 19 :0 -0 0 714 20 06 19 :0 -0 0 718 20 06 19 :0 -0 0 722 20 06 19 :0 -0 0 726 20 06 19 :0 -0 0 730 20 06 19 :0 -0 0 803 20 06 19 :0 -0 0 807 20 06 19 :0 -0 0 811 20 06 19 :0 -0 0 815 20 06 19 :0 -0 0 819 20 06 19 :0 -0 0 823 20 06 19 :0 -0 0 827 20 06 19 :0 -0 0 831 06 :0 0

DP (kPa)

Permeate TDS (mg/l)

Product Flow

RO Performance

FIGURE 4 Reverse osmosis performance

maintaining this level of performance.

By mid-June 2019, the turning point is reached where the normalised indicators cross the FIGURE 3 Iron and actual measurements manganese build-up and the differential pressure starts to increase. The manufacturer’s specifications advise an RO CIP if the normalised indicators vary by 15%. The first CIP on the RO was performed in September, returning performance to initial conditions.

Way forward This shows a challenging operational environment. The process has proved effective, and acid CIP effectively restores both RO and UF operation as expected with iron and manganese fouling. However, the risk of oxidation damage due to iron and the reduction of membrane life due to frequent CIP is of concern.

The highly unpredictable nature of feedwater quality and the costs involved to monitor this create an impractical situation. Ideally, the erratic behaviour of the borehole quality must be understood. An inspection of the borehole internals will be performed, and more data will be collected and compared to the current tide.

Effective management of the feedwater can significantly improve the ability to effectively operate the plant, extend membrane life and keep operating costs to a minimum. *Nico-Ben Janse van Rensburg is a process engineer at Quality Filtration Systems.

sustainable & long term

WATER

STORAGE

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www.prestank.co.za

WATER & WASTEWATER

Extending asset life digitally Digital transformation is blending information and operational technology for asset performance improvements that reduce costs, optimise efficiency and improve conservation in water and wastewater operations.

T

he United Nations projects that if current water usage trends continue, the world will have only 60% of the water it needs by 2030. This pending scarcity compounds pressures already mounting in the industry.

Within South Africa, factors that present a major threat to organisations that treat and deliver water include ageing infrastructure, cash-strapped municipalities, and the outflow of skilled older personnel at a faster rate than they are being replaced.

Others include climate change and extreme weather events, and the looming threat of cybercrime.

“While the industr y attacks such challenges on many fronts, including water conser vation and demand management, improving asset per formance is one of the most effective strategies a water and wastewater plant or network can take to reduce costs and protect quality,” says Jacques Squire, segment leader: Water and Wastewater, Schneider Electric South Africa.

According to Squire, asset management has become a top concern among a growing number of water operations, with 42.7% of water industr y respondents citing

‘maintaining or expanding asset life’ as their most significant sustainability issue.

“ARC Advisor y Group reports that moving up the scale from preventive and condition-based approaches to predictive and prescriptive strategies has enabled users to cut the cost of maintenance labour and MRO (maintenance, repair and operations) materials by 50%,” he explains. “ARC analysts also estimate that, on average, industrial operations lose about 5% of their operating budgets to downtime, which can be reduced to zero through more sophisticated asset management techniques.”

New capabilities to collect, analyse and share process data digitally bring the benefits of asset per formance improvement well within the reach of even the smallest operations. Results offer a 50% reduction in maintenance costs, a 30% reduction in energy costs, and 5% improved productivity.

Implementation through IIoT Achieving asset per formance management in a cost-effective way involves augmenting traditional client/ser ver information architectures with technologies such as industrial internet of things (IIoT) gateways, edge analytics, and cloud computing, which are more open and amenable to digital control.

“Collecting operational data from connected assets, such as pumps, and sharing it with real-time decision support

New capabilities to collect, analyse and share process data digitally bring the benefits of asset performance improvement well within the reach of even the smallest water and wastewater operations

applications – in the cloud or on premises – is how digitisation improves asset per formance,” says Squire. “It involves bringing information technology (IT) and operational technology together securely in ways that were not feasible previously.”

EcoStruxure architecture for water and wastewater provides a platform that can guide the management, integration, evolution and protection of digital infrastructure as clients move to the benefits of asset per formance improvement. It models the flow of information from smart field devices at the base layer, through gateways and controllers at the middle and edge layers, into IT applications and analytical ser vices for ultimate presentation to decision-makers.

Partitioning digital infrastructure in this way provides an orderly framework for introducing digital technologies to improve asset performance. It will help to achieve the following three objectives: - secure baseline reliability of assets - enhance baseline reliability through advanced IT and digital applications - optimise asset performance strategically, enhancing digital tools and techniques through further integration with multiple assets and all relevant plant operating data.

“Most of our clients who implement asset performance improvement programmes begin seeing a return on investment in as little as three months,” concludes Squire.

WATER & WASTEWATER

Mastering open-channel flow measurement and monitoring Monitoring water and effluent flows is a key environmental consideration.

Here, the effective and accurate measurement of an open channel can be challenging and requires specialist experience combined with the best methodology to match site conditions. By Peter van der Merwe*

F

lumes are the primary measuring device in open-channel flow measurement and their advantages are numerous. These include minimal head loss, adaptability to a variety of channel shapes, and the ability to measure wide flow ranges with custom-designed structures. The latter are manufactured within the constraints of laboratory calibrations and the relevant international standards. All flume ratings depend on laboratory calibration.

Flow measurement methods are continually being upgraded and new concepts exploited.

These offer the promise of ever-increasing

Rectangular longthroat flume

convenience and improved economics for water control and management. They confront the difficult problems associated with measuring open-channel flows and can provide water resource managers with vital operational data in locations not deemed measurable.

A common way to gauge flow through an open channel is to measure the height of the fluid as it passes through the flume or weir in the channel. The flow height is the indicator of the flow volume and, therefore, provides an established measurement for the secondary device of the flow rate. The secondary device is typically an electronic monitor (ultrasonic).

Combined, the primary and secondary

Parshall

stages complete the flume measurement loop.

The primary device is necessary to convert channel flow to a cross section of the channel for repeatable head production and accuracy. The carefully constructed geometry of the primary device (together with a calibrated staff gauge) verifies the monitoring of the flow by the secondary device.

Staff gauges are an inexpensive, simple, robust and absolute method of determining water flow through a flume or weir. They can be utilised, without the use of rating charts, by relatively unskilled staff. However, staff gauges can only be used for spot measurements. It is

IMIESA February 2020

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WATER & WASTEWATER

that yield consistent results, depending on the operating conditions.

Khafagi flume

difficult to obtain readings in the field with a true resolution higher than ±5 mm.

Estimating open-channel flows Various measurement methods can be applied.

The following yield mixed results: - Manning’s formula and the challenge of accurately determining the ‘n’ roughness coefficient. The ‘n’ values can vary greatly along a given stretch of channel and over time, due to encrustation and the deterioration of the channel. The formula is acceptable for the engineering design of a channel, but not for continual monitoring, since the results would not be expected to provide better than 30% accuracy in field conditions.

- Velocity area method (ASTM D3858-95).

To quote from this standard (Item 11.1): “Determination of the precision and bias for this test method is not possible… due to the high instability of open-channel flow.”

Furthermore, “Results indicate that when using area-velocity meters in controlled environments, errors in excess of ±10% in discharge are possible.” This is according to the US Department of the Interior, Bureau of Reclamation Hydraulic Laboratory Report HL-2012-03 (Laboratory Evaluation of Open Channel Area-Velocity Flow Meters).

- Slope area method (ISO 1070) (Item 1 Scope). This method is subject to the large uncertainties of the Manning’s roughness coefficient and is even less accurate than the velocity area method. The slope area method is used for determining the extreme high-stage end of rating curves in cases of floods.

The most common flume models Below are examples of measurement models

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IMIESA February 2020

The British Standard flume The British Standard (BS) flume is now known as the rectangular longthroat (RLT) flume. The BS 3680: Part 4A:1981 standard has been superseded

by BS ISO 4359:1983 and subsequently ISO 4359:2013. These flumes are individually designed to the ISO standard for specific channels.

The ISO 4359 standard also covers trapezoidal and U-throat flumes. The condition for these flumes is that the flow in the approach channel is reasonably uniform and steady. With reference to the current ISO 4359 standard, the expression ‘Venturi’ is not applicable to open-channel flumes. A Venturi meter is used within a closed conduit system and relies upon gauging the head at two locations and the application of Bernoulli’s energy equation.

The Parshall flume The Parshall flume was developed by Dr Ralph Parshall of the US Soil Conservation Service, primarily to measure irrigation water flow. It is now used in industrial and municipal sewers, and in sewage treatment works on condition that the flow in the approach channel is reasonably uniform and steady.

The original Parshall flumes are specified by ASTM D1941-91 (ASTM International, formerly

Palmer-Bowlus flume

known as American Society for Testing and Materials). Caution is needed when obtaining dimensions from the many sources on the internet. Only the ASTM dimensions are requisite to obtain a true and accurate rating of the flume.

The US Parshall flumes are specified by their throat width: the sizes range from 1 inch to 300 inches (25 ft). ISO 9826 specifies a range of Parshall flumes by a model number 1 to 21.

The two ranges of Parshall flumes (US and ISO) are not similar in geometry or rating. The misunderstanding of the two types occurs when a bill of quantities indicates the ISO standard and the drawings the US standard.

Every Parshall flume is an empirical device, hydraulically and individually calibrated, and no intermediate sizes are standardised by either ISO or ASTM. Parshall flumes are not scale models of each other.

The Khafagi flume Matching the shape of the channel to the streamline curvature of the Khafagi flume achieves a 4% higher flow than would be available with the same water depth. The average divergence between theoretical calculations and practical measurements is not more than 1%. The condition is that the approach flow is reasonably uniform and steady. The Khafagi flume was developed specifically for sewage flows.

The Palmer-Bowlus flume When utilising a Palmer-Bowlus flume, the diameter of the flume is not necessarily the primary factor to suit an incoming pipeline of the same size. According to the ASTM D539093 standard for this flume, it is recommended that the maximum head be restricted to half the throat length – i.e. 0.5 D. A more suitable flume is the ISO 4359 U-throat. With reference to ISO 8368, these flumes are well suited for the measurement of flows in conduits running partly full.

The hybrid flume H (hybrid) flumes were designed in the mid-1930s by the Soil Conservation Service of the US Department of Agriculture.

They are capable of monitoring flows that vary over wide ranges with a high degree of accuracy, as their design allows for the relatively accurate estimation of both low and high flow. An H flume is the result of a combination of the physical and

WATER & WASTEWATER

mechanical characteristics of a weir and flume.

Its shape resembles a triangular weir more than a flume. From a mechanical perspective, the H flume is capable of passing run-off that contains a heavy sediment load, solids and floating debris.

The H flume was developed to measure the flow of irrigation water from small catchment areas and surface water. Today, it is generally used to measure the flow of irrigation water, slow-flowing watercourses, and water in

sewer and industrial systems.

In free-flow conditions, the precision of an H flume is comparable to that of other flumes. To obtain this type of precision, these flumes need to be manufactured with close attention to detail in compliance with the standard dimensions.

This is a very versatile flume, as it combines the best features of both the weir and flume. It accurately ISO and ASTM Parshall flume discharge equivalents measures both low flows (like weirs) and high flows (like flumes), and offers the advantage of through-flow for flatbottomed flumes. This flume performs well under perturbed flow conditions, plus the length of the approach channel – at twice the maximum depth – will be sufficient.

APE Water Week.pdf 1 2020/01/21 4:44:48 PM

H (hybrid) flume

In conclusion, the important point to make from all these observations is the need for a detailed understanding of the flow characteristics and conduit properties.

This will then determine the optimum measurement approach. *Peter van der Merwe, Pr Tech Eng, MSAICE, MPET, MCET, MWISA, is a consultant at Flumes and Weirs. Email: flumesandweirs@gmail.com

GEOMEMBRANES

Extending reservoir life, preventing precious water loss

Tests performed on Aquatan Lining Systems’ Hyperliner geomembrane installations consistently prove that the material maintains its tensile properties for decades.

P

otable water reservoirs are strategically positioned within a municipal system to store and ensure daily continuity of supply in the final and direct delivery stage to consumers. Some are new and fully functional, but decades-old concrete structures will have inevitably experienced a greater or lesser degree of concrete wear and tear, which can and does lead to unaffordable leakages.

This sometimes reaches such a critical stage that their concrete housing exhibits growing cracks or joint failures, resulting in such severe water losses that the primary concern is containment of the problem. In extreme cases, it can lead to their closure as a short-term water loss prevention measure.

However, that doesn’t address the immediate community needs. Primarily, such a closure is

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IMIESA February 2020

deemed the only affordable solution due to the misconception that the repair is an extremely expensive exercise or possibly even requires the replacement of the reservoir.

The upside is that there are practical and more economical solutions available. Aquatan has perfected a remedial process of lining the deteriorated concrete reservoirs – a prime example being Aquatan’s proprietary Hyperliner (ethylene vinyl acetate copolymer) geomembrane.

Since the company’s foundation in 1966, approximately 50 new and existing reservoirs have successfully been either lined or relined as an after-market intervention with Hyperliner.

In the process, critical infrastructure has been restored, preventing extensive losses of valuable water resources. Hyperliner is produced from a proprietary polymer, with a typical service life of 20 to 30 years.

Hyperliner benefits Hyperliner’s unique properties are being chosen for these applications for the following key reasons: • Hyperliner is very flexible. Furthermore, due to its unique formulation, Hyperliner is not subject to stress cracking, has a high puncture resistance, is durable, and can accommodate anticipated movements within the structure.

• It exhibits exceptional ageing resistance.

Aquatan’s floating roof installed on the Neptune Reservoir in Simon’s Town

• It has the ability to conform to threedimensional shapes, typically present in reservoirs.

• It has an exceptional tear resistance.

IGS and IAGI membership Aquatan has been a corporate member of the International Geosynthetic Society (IGS) since 2013. This organisation imposes strict quality and performance standards on its members.

Additionally, and more importantly, Aquatan has also been a member of the International Association of Geosynthetic Installers (IAGI) since 2013 and is the only accredited Approved Installation Contractor (AIC) in South Africa.

“Our AIC status is a significant achievement since we are the only IAGI contractor in South Africa, with around 60% of our welding technicians being certified in accordance with IAGI standards,” says Piet Meyer, managing director, Aquatan.

“In-house, and to support our multifaceted product manufacturing and installations, we’ve developed a digital, cloud-based quality control system. This monitors, records and reports on all aspects of quality control data on-site by means of a tablet, to which all project stakeholders can

GEOMEMBRANES

BBBEE DEAL CONCLUDED To further enhance its ‘preferred infrastructure partner’ status, Aquatan has embarked on a transformation path, providing a shareholding of 32.5% to a 100% black-owned and -managed investment company, Thembani Sicebisane. The deal further strengthens the Aquatan board through the appointment of two highly experienced black female directors.

Thembani Sicebisane’s goal is to build an investment portfolio within the construction, industrial and infrastructure sector and it recognises the value of acquiring an interest in Aquatan – a market leader in its field. The acquisition will further strengthen Aquatan’s penetration of both the South African and broader international market.

have access on their mobile phones, tablets or computers in real time – wherever they are,” he expands. “This is an invaluable tool, as we work on remote sites all over Africa and beyond.”

Classic case studies: the Waterval and Durban Heights reservoirs Within the municipal and water utilities sector, the Waterval and Durban Heights reservoir projects serve as outstanding examples of how a Hyperliner solution was able to extend their operational life.

The 45 Mℓ Waterval reservoir in Roodepoort, Gauteng, was originally constructed around 1954. Over time, concrete elements had deteriorated and the reservoir was no longer watertight and serviceable. That was the starting point for Aquatan’s proposal for a new lease on life, working with the professional team and contractor.

The original 81.1 m diameter circular reservoir had a gravity-type mass concrete wall, which had proved to be inadequate in terms of strength. A new, post-tensioned concrete wall was constructed on the inside of the existing wall to ensure the future water-tightness of the reservoir. Aquatan was awarded the contract to line the walls, floor and columns of the entire reservoir (9 260 m²) with its 2 mm Hyperliner geomembrane.

All wedge welds were pressure-tested, extrusion welds were spark-tested and

A Hyperliner system was installed at the Durban Heights Reservoir in 1991 to counter a serious leakage problem that was ℓ causing a daily water loss of some 300 kℓ

T-joints and intersections were vacuum-tested.

The allowable leakage rate was specified as 10 litres per minute (ℓ/m) at a full water depth of 8.45 m. The end result saw a leakage rate of 8 ℓ/m at a water head of 8 m recorded, which passed the test.

“The guaranteed service life of the reservoir rehabilitated with 2.0 mm thick Hyperliner is 20 years,” states Meyer. “Previous experience of the performance of EVA liners, however, indicates that the service life would be well in excess of this period.”

Durban Heights In terms of scale and scope, Umgeni Water’s 340 Mℓ Durban Heights Reservoir No.3 is a much more distinctive structure and one that has stood the test of time since its construction in 1971. Internally, that’s largely due to Aquatan’s Hyperliner, which was installed in 1991 to counter a serious leakage problem causing a daily water loss of some 300 kℓ.

The roof is supported by a 50 m high cylindrical tower designed to be immersed to a height of 25.65 m at full storage capacity. To protect the integrity of the submerged concrete structure, and to keep it leak-free, the entire surface area is protected by the membrane system installed, including the internal and external surfaces of the 11.28 m diameter tower, to just above the 25.65 m threshold.

At the time, the installation of geomembranes was considered a groundbreaking decision, given A successfully completed Hyperliner project at the Parktown Reservoir

the reservoir’s size and depth. “It was probably the largest reservoir in the world to rely on a full geomembrane lining to keep the structure watertight,” says Meyer.

About 30 000 m2 of Hyperliner 1500 was installed at Durban Heights. Aquatan made use of its computer-aided design software to optimise sheet cutting and placement, reducing the original anticipated wastage from 15% to 7%.

Back in 1991, the original geomembrane lining contract, including remedial concrete work, was completed at a cost that resulted in a significant return on investment in close to three decades of operation.

Prior to this installation, the Hyperliner system had already been proven on several landmark South African projects. These include the lining of the Drakensberg Pumped Storage Scheme’s headrace tunnel, the lining of the Huguenot Tunnel, as well as floor lining for major thickener tanks employed by the mining industry.

Dr JS Moroka Municipality Another remarkable project was the rehabilitation of eight severely leaking reservoirs ranging in size from 500 Kℓ to 16 Mℓ for Dr JS Moroka Municipality. The eight reservoirs were lined with 2.0 mm Hyperliner between October 2010 and September 2011.

Over the years, Aquatan has also installed Hypalon/HDPE floating roof membrane designs for older, uncovered reservoirs in place of an alternative retrofit concrete roof structure.

Examples include the Simon’s Town Neptune Reservoir constructed around 1940. Aquatan’s solution proved to be the most practical and cost-effective.”

“In South Africa and many countries across the rest of Africa, we continue to supply and install bespoke solutions for any form of fluid containment – from municipal projects to largescale mine dams. This experience, backed by our technology suite and internationally accredited quality systems, makes us a preferred infrastructure partner,” Meyer concludes.

www.aquatan.com

IMIESA February 2020

35

SANITATION

Mother Nature excels at sanitation, hygiene and sustainability. The waste of one life is the banquet of another. If we adopt a similar approach to sanitation, we can create an efficient, economical, hygienic and sustainable solution.

By Alan Hall, inventor

N

The crossbar is of great help to children, disabled and elderly.

Registered designs, trademarks and copyright apply

o one manages waste better than Mother Nature; she excels at sanitation, hygiene and sustainability. Trees and grasses exude oxygen, leaves, fruits, seeds and cereals – all of which are a banquet for billions of other life forms. Animals provide a banquet of meat, milk and leather, etc. We, as humans, have an obligation to maintain this discipline so that our waste is a banquet for billions of life forms.

Humans, for example, take up nutrition from the ground, the air and clean water. Our consumption transforms this into energy and excreta such as carbon dioxide, urine and faeces. The urine does not follow the same trajectory as the faeces.

This maintains isolation where the urine is absorbed by the ground to be an excellent fertiliser with soluble nitrogen, potassium and soluble phosphate. If it is not used as a fertiliser, it remains a harmless potential fertiliser.

Now, high-density living requires a different approach to solid waste; we need to introduce dehydration, incineration, isolation and dispersion to nature’s methods for better, faster and more hygienic results.

A circular sanitation approach

in an airtight chamber to increase the pH to 9. This ensures that any pathogens are neutralised. Adding copper to the urine also kills pathogens and is one the best fertilisers in the world.

The dried solids are combusted. Each person produces less than 200 grams of ash per year, which can safely be added to compost.

Imagine a world with control over pathogens, parasites, soluble/insoluble phosphate and waterless sanitation: • Existing water storage would be sufficient.

• The cost of community health would drop by 50% and NHS could be a reality.

• The sanitation backlog could be reduced within years.

• Mining of phosphate would drop 30%.

• Plastics for food would drop by 30%.

• The distance travelled to bring food to cities would drop by 30%.

• Everyone can green up and feed up their families, especially the poor.

• The collection of household waste and industrial waste would drop by 90%.

• Social tension would be alleviated in urban and rural areas.

• Billions of hectares would be restored to health by improving soil quality.

Waterless sanitation

FIGURE 1 Examples of waterless toilets in a cubicle and in a bathroom

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IMIESA February 2020

The LUSEC Sanitation Solution is a dignified, healthy and sustainable solution to sanitation and recycling, without water. The lack of water ensures that there is less smell, nor do the parasites and pathogens survive. Smell and disease are very easy to manage without water in the process.

Human effluent is separated in the pedestal. The urine is stored in watertight reservoirs and the solids dry in a ventilated chamber. The urine is isolated and stored

A circular approach The linear economy is not just waste; it is death to the circle of life. However, it is very easy to have a circular economy if we just add treated urine to the soil and burn faecal waste to kill pathogens and parasites. Solid waste is not worth much to the soil, but urine is very valuable.

The nitrogen in urine accelerates the decomposition of lignin and fibre, and the soluble phosphate remains soluble

SANITATION

FIGURE 2 Phosphate uptake by plants and microbes

for easy uptake by plants and microbes.

The potassium is always at hand to complete the macronutrient diet.

The LUSEC Sanitation Solution keeps urine under a layer of oil to stop odours and the loss of nitrogen. The copper added for sterilisation is also an excellent addition for fertiliser and soil health. The phosphate remains soluble.

After three years of testing the reliability and hygiene of the waterless toilets at Celimfundo School in the Khetani Township in Winterton, KwaZulu-Natal, a clear line can be drawn between waterless sanitation and flush toilets, hire toilets and composting toilets. The waterless toilets are low maintenance without a single part broken and the preference by the children is clear cut. Other types of sanitation continue to carry the risk of pathogens and parasites.

Flush toilets start a toxic journey of waste in the pedestal that accumulates other debris such as plastic, paper, plants and a host of industrial pollutants that are not sanitised and cannot be isolated. The only way the risk to health is reduced in the water is by the dilution and dumping of sludge. Modern jargon speaks of ‘treated water’; however, this is still toxic.

Chemical reactions in the sludge create a product that has a pH of 10. To reduce the toxicity of the sludge, ferrous chloride and/ or aluminium chloride are added to bring the pH down to 8. By this stage, the waste of

thousands of people has been consolidated into a poison that includes heavy metals and phosphates that cannot be regarded as fertiliser. The phosphate has become unavailable to plants and microbes in the soil.

This is a big mistake because every living cell requires phosphate.

Every farmer or horticulturalist is challenged daily to get the soil right for best plant growth. It starts with soluble phosphate. There is plenty of phosphate in the soil but it takes skill and time to make it soluble. Only when the pH of the soil is between 5.8 and 6.2 is phosphate available to the plant in large quantities.

Biodigesters seldom work because the sludge is usually out of the pH range for microbes to do their work.

The world’s best fertiliser Urine as a fertiliser has many benefits. It is free and contains nitrogen, potassium and phosphates that are soluble and available for uptake by plants. Plants grow for only a few months of the year, but urine benefits the soil throughout the year by adding nutrition to the microbes in the soil and by breaking down vegetation into excellent compost, just as nature intended, for maximum yields.

Naysayers argue that excess application of urine would be detrimental to soil because of the sodium in the urine; however, if only tiny amounts are applied to the soil on a regular

FIGURE 4 Flowers grown with urine as the fertiliser

FIGURE 3 Pecan nut tree (2) treated with urine has more new foliage

basis, it gives the soil time to leach the sodium out of the top layer.

I tested toxicity by applying 20 litres of concentrated urine to one pecan nut tree. No damage has been done and the vegetative growth has been prolific. Figure 3 shows the difference between the treated and untreated trees – the treated tree grew (tree 2) new leaves while the other (tree 1) did not.

Another perspective is that farmers use superphosphate as a fertiliser. On good soils, where the pH of the soil is optimum for every 1 000 kg of applied superphosphate, only 8 kg of this phosphate enters the plants. The rest of the phosphate is unavailable. The soil provides additional phosphate for the plant. If the soil is not right, the yields aren’t good.

Where to from here?

We cannot blame municipalities for the lack of service delivery – taking back toxic water and waste of over 300 compounds is an impossible task. Dump sites and flush sanitation are short-sighted and destined to fail; however, waterless sanitation provides an efficient, economical, hygienic and sustainable solution.

Sanitation must be decentralised, and horticulture encouraged everywhere. It is best to start with the quick wins: households and communities without flush sanitation.

Waterless sanitation can plug the gap.

Every adult produces enough fertiliser from urine alone, in one year, to produce 300 kg of tomatoes, but the soil pH has to be right. The green revolution is at our feet.

For more information, contact the author at thelusec@gmail.com.

IMIESA February 2020

37

ENVIRONMENTAL ENGINEERING

A wired world

Welded mesh systems are gaining ground, alongside traditional hexagonal twisted wire, for a range of gabion installations. By Alastair Currie

W

hile functionality is the primar y consideration in environmentally engineered structures, there’s an increasing demand for aesthetics to play an equally important role. This trend has enabled architects, engineers and landscapers to integrate gabion systems in creative ways for a range of projects that include residential and commercial developments.

These extend from culvert outlets to wing walls, freestanding walls, retaining walls, mattress linings and stepped spillways.

Gabions are now also an increasingly popular choice as a building cladding system, with or without vegetation.

“The architectural side of our business is experiencing unprecedented growth,” explains Louis Cheyne, managing director, Gabion Baskets, which specialises in the manufacture of gabion systems, the supply of geotextiles, in addition to offering technical design recommendations and installation services. All mesh materials are manufactured from local steel and galvanised or supplied with a zincaluminium coating.

Gabion elements outside the factory.

These were anchored into the concrete floor using 20 mm rebar

ARCHITECTURAL CLADDING: INDUSTRIAL Assembly of a low-level gabion wall as an architectural element for an industrial client. Some sections were built in front of older low-level concrete retaining block walls that the client wanted screened off to establish a cleaner look

“We now have a dedicated subcontracting unit that works with professional teams to develop custom solutions. Gabion construction may seem straightforward, but it’s actually a very specialised field that requires expert advice,” he continues. “The end result is a natural effect that blends in more effectively than mass concrete structures. Since gabions are permeable, they are also far more sustainable.”

Recent project examples include a Sandton townhouse complex, which has a river running through the property.

Various environmentally engineered structures form key design elements of the overall development. This includes internal and external river works and stormwater systems constructed using galvanised hexagonal woven mesh.

These structures were installed by landscape architects Naledi Natural Stone. In addition to supplying the

ENVIRONMENTAL ENGINEERING

An example of a welded mesh wall

WELDED MESH mesh systems, Gabion Baskets provided installation training and recommendations in terms of the materials and quantities.

Approximately 3 000 m3 of gabions was specified, equating to 30 tonnes. Between 4 000 and 6 000 tonnes of rock was used. The typical work rate was around 1 m3 per worker per day, which is regarded as optimal.

Welded mesh For architectural applications, welded mesh is the ideal material for building cladding systems. At present, Gabion Baskets fields three main wire diameters, namely 3.00 mm, 4 mm and 6 mm. The most

SANDTON RESIDENTIAL DEVELOPMENT

River erosion works constructed at a townhouse development in Sandton.

Around 10 tonnes of gabions went into the construction of the various environmentally engineered elements.

The gabion mattresses seen here were supplied in 2 m long sections. This proved ideal in creating a uniform effect

common aperture configuration is 50 mm x 50 mm x 3.00 mm.

Wire coating options include Class A or C galvanisation; however, black mesh is proving to be another popular choice. With black mesh, an intentionally weathered effect is created by allowing the ungalvanised wire selected for these projects to rust slightly prior to spraying with a clear coating finish to create a durable rustic effect. Stainless steel welded mesh can also be specified.

“Welded mesh is intentionally rigid in nature, since it’s predominately used to construct flat vertical wall systems to the very precise tolerances specified by architects,” Cheyne continues. “The quality of these welds is exceptional, influenced by developments in the mining sector for areas like roof and stope support.”

For architectural cladding, typical walls range in height from 2 m to 3 m and they’re not designed to take a load. In contrast, the woven mesh systems used for river

An attenuation pond bordering a wetland. All gabion and gabion mattress systems on this development use galvanised hexagonal woven mesh

works and retaining walls are intentionally designed for strength, since loading is a key design factor.

“Being rigid, welded mesh is also not suitable for river systems, since flexibility is the key here. In this instance, galvanised hexagonal twisted mesh would be specified and ideally PVC coated to provide maximum protection against river pollution and scouring,” Cheyne explains.

On a recent commercial project, Gabion Baskets supplied a 50 mm x 50 mm welded mesh. Instead of the usual 100 mm to 250 mm sized rock, this smaller mesh configuration created a more striking aesthetic effect. However, with a smaller sized rock, the void ratio was less, requiring more material for this project. That translated to around 2 tonnes of material per cubic metre, compared to around 1.6 tonnes for standard sized rock.

Design being a personal perspective, some clients still intentionally choose flexible mesh as opposed to welded mesh to create cladding elements. On a recent project, a steel manufacturer specified traditional hexagonal mesh to establish an industrial theme tying in with their business.

“Depending on the height of these cladding walls, steel bar reinforcement and a concrete support base may be required.

The same would apply for freestanding and boundary gabion walls, which are now gaining in popularity,” Cheyne adds.

“The point to emphasise is that gabions are engineered structures and – as with any civil or building elements – function and aesthetics need to coexist exactly.

That’s where our decades of experience in designing and building gabion systems proves invaluable,” Cheyne concludes.

A gabion stormwater management system

IMIESA February 2020

39

CEMENT & CONCRETE

Together, Jukskei and Wynberg have a fleet of around 45 readymix trucks serving the plants

Within the Rosebank, Sandton and Midrand nodes, AfriSam’s Jukskei and Wynberg readymix operations work with developers to form Gauteng’s iconic landmark structures.

By Alastair Currie

Shaping the future with readymix

W

hen it was completed in 1973, Johannesburg’s Carlton Centre was the tallest building in Africa, at 223 m. Decades later, that title has been claimed by The Leonardo in Sandton’s CBD, a mixed-use tower that reached its final height of 234 m in 2019.

For each of these imposing structures, readymix concrete was a key factor in managing the work rate and quality required.

And in both cases, AfriSam was the readymix supplier. (On the Carlton Centre project, AfriSam then traded as Pioneer Concrete.)

“Today, we can pump readymix to impressive heights and over extended distances thanks to specialist pumping systems and admixture formulations,” explains Kevin Naidoo, operations manager: Readymix, responsible for AfriSam’s Jukskei and Wynberg Central Cluster. Together, Jukskei and Wynberg have a fleet of around 45 readymix trucks serving both dry and wet batch plants.

“Back in 1973, those technologies didn’t exist and so pouring readymix tended to be a time-consuming process and not an exact science. Batching systems were manually operated, and the industry still relied on skips and in some cases even lifted entire readymix trucks from ground

40

IMIESA February 2020

level to higher storeys to complete pours,” he continues.

In modern times, advances in readymix technology have completely changed the way projects are designed and constructed.

They are now faster and far more efficient to complete.

“At AfriSam, we provide custom readymix designs and utilise sophisticated computerised batching processes that guarantee mix repeatability to meet the exact engineering specification for every project,” says Naidoo. “It all hinges on technical excellence and, for this reason, we continue to invest in the skills and equipment needed to meet current and future requirements.”

High-rise pumping At The Leonardo development, AfriSam Wynberg deployed purpose-designed static pumps to deliver readymix up to the final building height with the aid of admixture retarders. A similar approach was applied at the 26-storey PwC Tower headquarters building in Waterfall City, Midrand, where AfriSam Jukskei was the readymix supplier.

For the PwC project, AfriSam supplied around 19 custom mix designs, formulated at the Jukskei laboratory. According to AfriSam, the batch accuracy was within

AfriSam’s Jukskei A was the primary supply plant for the PwC Tower

1% on all materials batched, underscoring the exceptional quality control achieved throughout the project.

“On projects of this scale – at some stages running 24 hours a day – the timing between the batch plant and the site is crucial to ensure just-in-time delivery and to keep readymix truck standing times to a minimum,” Naidoo explains. “Our quality control systems track every production stage in near real time.”

At 118 m in height, the PwC Tower is believed to be the 24th tallest twisted building worldwide and the first in Africa.

On the PwC Tower, each floor incrementally rotates 1.2 degrees relative to the one below.

AfriSam’s Jukskei A was the primary supply plant, with Jukskei B serving as a backup. During the 24-hour phases, three readymix trucks operated on a permanent turnaround basis.

“Given the quarry’s close proximity, we could reduce the batch size to 2 m³ in order to avoid slump retention issues,” explains Naidoo.

For the building’s central core, slipforming was used from ground level. Here, readymix was the perfect choice to achieve the continuous pours and successive sliding

CEMENT & CONCRETE

For the PwC Tower’s central core, slipforming was used from ground level.

Approximately 6 057 m3 of readymix was used to form the core

progression of the formwork. Approximately 6 057 m3 of readymix was used to form the core.

AfriSam was tasked with devising mix designs that were both pumpable and suitable for slipforming. Readymix formulations also needed to accommodate

the pumping pressure within the pipeline, especially at increasing heights. With the use of superplasticisers, extended workability of up to six hours was achieved.

During pumping operations, the pressure had to be constant. Aggregate grading and fines content quality control were equally critical factors. Had incorrect grading occurred, aggregates could have been pushed out during pumping, causing potential blockages in the pump and/or pipeline.

AfriSam supplied 19 custom mix designs for the PwC project, all of which were formulated at the Jukskei laboratory

Wynberg and Jukskei At The Leonardo development, AfriSam Wynberg deployed purpose-designed static pumps to deliver readymix up to the final building height, with the aid of admixture retarders

AfriSam runs 18 readymix operations within Gauteng, each strategically positioned to serve designated regions. Aggregates for the Wynberg and Jukskei operations are mined at AfriSam’s Jukskei quarry in Midrand. Here, products produced comprise G1, G5, -8 mm crusher sand, and 9.5 mm, 13.2 mm and 22 mm stone.

Both operations are strategically placed within major growth nodes. AfriSam Wynberg is believed to have supplied around 70% of the high-rise developments within the Sandton CBD. Recent interrelated infrastructure projects include the M1 Grayston pedestrian bridge and ongoing BRT projects. Currently, AfriSam is supplying readymix for various BRT terminals being constructed on routes connecting Sandton with the Johannesburg CBD. In turn, AfriSam Jukskei has been a major supplier to landmark developments within Midrand’s Waterfall City mixed-use precinct.

These include the Mall of Africa, where AfriSam supplied approximately 50% of the readymix, and the PwC Tower, as mentioned.

Established in the 1950s, the Jukskei quarry has been an integral part of the infrastructure mix since inception. Once situated in a quiet rural setting, the landscape has changed dramatically in recent years, with commercial developments springing up on land adjacent to the mining boundary.

A major catalyst was the construction of the N1 Ben Schoeman Highway in the 1970s.

AfriSam Jukskei was also a major supplier for the Gauteng Freeway Improvement Project, Gautrain and more recently the Allendale Interchange upgrade that facilitates improved traffic flows into Waterval and Midrand.

“With an estimated remaining life of mine in excess of 20 years, the Jukskei quarry still has a major role to play in serving growth in the Midrand and Sandton regions,” says Naidoo. “Large tracts of private land are available for development.”

Current and future urbanisation surrounding the mine does not impinge on its operations; however, it does mean that environmental, health and safety management become even more stringent.

“AfriSam’s Jukskei quarry will continue to coexist and meet commercial and residential demand for many years to come in a well-controlled and sustainable manner,” adds Naidoo.

“In the immediate future, we’re looking for ward to a long-awaited upturn in infrastructure spend going into 2020.

Alongside this are a series of large commercial projects in the pipeline where AfriSam is well placed to meet their requirements. Today, readymix is an exact science and it starts with the optimum aggregate selection,” Naidoo concludes.

IMIESA February 2020

41

Safer routes with precast

T A STRONG FOUNDATION FOR INFRASTRUCTURE SUCCESS ROCLA is South Africa’s leading manufacturer of pre-cast concrete products.

Surpassing 100 years of product excellence.

• • • • • • •

Pipes Culverts Manholes Poles Retaining walls Roadside furniture Sanitation

Including other related products within infrastructure development and related industries.

Visit us on

www.rocla.co.za

for our nationwide branches

Technicrete kerbs forming part of a car park design at an office development

he widespread construction of kerbs only began in the 18th centur y, despite them having been around since the days of Pompeii. Originally utilised for the beautification of the city and to separate transportation from pedestrians, the humble kerb has evolved into an infrastructure necessity, by, for example, preventing drivers from parking on pavements and lawns in addition to providing structural support for pavement edges.

Technicrete’s precast barrier kerbs have been successfully installed on numerous regional infrastructural projects throughout South Africa due to their 100% local fabrication and excellent quality. The kerb uses the half-battered profile.

This more vertical face offers a type of barrier to motorists for them to be sufficiently aware that they are dangerously close to the edge. The sloping-back profile enables asphalt and compaction rollers to operate right up to the edge of the pavement without scratching or damaging the kerb face when the sur facing is laid.

On slower rural roads, the kerb can provide an element of safety through impact redirection. On fast-moving freeways and highways, the kerb is more often used for drainage and often applied near bridges where erosion is a potential factor and to ensure a clear and visible separation of people and motor vehicle lanes is established. A combination of a Technicrete barrier kerb and a C900 gutter section will convey drain water to the nearest kerb inlet. Any road resur facing requirements will not need realignment with the kerb line either. The Technicrete semi-mountable kerb can also be utilised in conjunction with the C900 gutter section for drainage purposes on roadways and elsewhere.

The company’s barrier kerbs have been specified for such projects as medical centres, national roadways,

CEMENT & CONCRETE

Bus shelters

private and commercial residential developments, gutter systems and rural infrastructure upgrading.

An example of a Rocla bus shelter installed in Francistown, Botswana

Within the transportation segment, precast is also gaining ground, with Technicrete’s sister entity, Rocla, fielding innovative solutions for the municipal market.

A prime example is Rocla’s vir tually indestructible and vandal-proof precast concrete bus shelter. The durability of precast guarantees decades of maintenance-free life – an important factor for cash-strapped local municipalities wanting to ensure budgets for street furniture are well spent.

These bus shelters can be supplied with wind walls for one or both sides of the shelter and, although supplied in a light grey colour, the sur face is easily painted for adver tising, roadside markings and community notice purposes.

Rocla also offers concrete taxi rank shelters and bus stops, as well as other related street furniture, such as concrete vendor stalls, sanitation units and concrete street lighting poles.

IMIESA February 2020

Find our branches at www.technicrete.co.za

p a v in g | mini ng | m as onr y

SUITABLE FOR: • Car parks • Industrial Estates • Retail Centres • Pedestrian areas • Domestic Drives • Motorways | Garages • Service areas

| k erb s | erosi o

n prot ectio

APPLICATIONS: • Tongue & groove • Standard grey or traffic calming colours • Precast • Various sizes available • Highest quality

n | re t a i ni

ng w a ll s | dra inag e

Technicrete is a subsidiary of ISG, a leading supplier of innovative infrastructure products to the construction and mining markets in Southern Africa.

43

CEMENT & CONCRETE

The danger of cheap aggregates Licensed, legally compliant and sustainable quarries are being put out of business by borrow pits opened to supply large-scale projects at cheaper prices.

Nico Pienaar, director, ASPASA

B

orrow pits are temporary sites that do not employ permanent workers, don’t invest meaningfully in capital equipment and have the potential to scar the environment in ways that can render tracts of land unusable for generations.

“While some in the construction industry, and even some engineering bodies, have called for easy access to ‘cheap’ aggregates, such an idea is ill-conceived and will lead to a catastrophe in the quarrying industry,” says Nico Pienaar, director of surface mining industry association ASPASA. “The knock-on effect is that hard-to-reach aggregates will be neglected, specialised crushing and screening equipment will not be procured and, as a result, aggregates for high-strength concrete and specialised construction will become unavailable. These cannot then be simply imported, as the cost of transport will make it completely unaffordable,” Pienaar continues.

ASPASA is currently engaging the Department of Mineral Resources and Energy, Sanral, the Department of Environment, Forestry and Fisheries, as well as other stakeholders in order to discuss the ramifications of ‘short-term remedies’ for cost saving.

“With proper planning, our industry has the ability to deliver whatever is required to build South Africa sustainably and to continue to thrive and employ ever-growing numbers of workers for generations to come.

Surely, that is a better solution!” Pienaar concludes.

DEFINING A BORROW PIT A borrow pit is a land use involving the excavation or digging of material for use as fill at another site and includes the pit area, stockpiles, haul roads, entrance roads, scales, crushers and all related facilities. They require approval by the Department of Mineral Resources and Energy, a permit to operate, and a pre- and postoperational usage and rehabilitation plan.

Further, they must comply with: • national and provincial legislation • local by-laws • water usage requirements • environmental requirements • the Mining Charter • MHSA Act (No. 29 of 1996) • labour legislation.

HEALTH & SAFETY

Why health and safety is alive and well The world is on fire. Climate change is becoming a climate crisis, and success and achievement are being rendered meaningless in the face of wider humanitarian concerns. The topic of safety has become so much bigger, and previous tried-and-tested methods for managing, mitigating and minimising risk are no longer enough.

W

hether you refer to it in full as the Fourth Industrial Revolution, or in its catchier acronym 4IR, its place is rooted firmly within contemporary technological innovation, and any effort targeted at digitisation will be applied against this revolutionary backdrop.

It is in full view of this socioeconomic landscape that NOSA has piloted its new training strategy, focusing on issues within the broader context of occupational risk, integrating current trends that affect us all. NOSA is incorporating systemic and systematic changes to its safety training suite, beginning with its flagship SAMTRAC course.

In its 2020 iteration, SAMTRAC has been refreshed, with the following enhancements and additions to its course offering: • Discussion related to ‘soft’ safety topics, such as corporate governance, fatigue management, psychosocial wellness, and management of change.

• Complete alignment to ISO 45001.

• Comprehensive examination of technology within risk management, touching on the benefits of AI/cognitive technologies, and the internet of things.

While full attention is given to the legislation

that regulates the course requirements, course developers have worked to create a holistic programme to enable students to navigate themselves through the current HSE climate.

Ultimately, a student completing SAMTRAC will be equipped as an HSE officer, and possess the knowledge and skills to perform their daily tasks, assisting their HSE manager with total compliance to their organisation’s integrated risk management system.

IMIESA February 2020

NOSA Testing now method accredited for NIOSH 0500, 0600, 7602 and HSG248 As we look to develop our service offering, NOSA Testing now offers accredited exposure monitoring analysis of asbestos, crystalline silica and alpha quartz GRAVIMETRIC WEIGHING AND CRYSTALLINE SILICA

ASBESTOS Analysis Asbestos

Asbestos Fibre

materials according to MDHS 77, HSE, United Kingdom and HSG 248, HSE, United Kingdom

accordance with HSG 248, HSE, United Kingdom

Accredited

TAT

Analysis

Sampling Media

Method Based On

Accredited

TAT

Size

Yes

72 hours

Inhalable and Respirable (Gravimetric)

Polyvinyl Chloride (PVC) Filters

NIOSH 0500 & 0600

Yes

48 Hours

37mm, 5µm

Yes

48 hours

Crystalline Silica

Polyvinyl Chloride (PVC) Filters

NIOSH 7602

Yes

10 working days

37mm, 5µm

For further technical information on our asbestos and silica capabilities, and to discuss your individual service needs please contact:

Keshav Beachen NOSA Testing National Sales Manager keshav.beachen@nosa.co.za | +27 (0) 71 442 9418

NOSA Testing Testing is is aa Level Level 2 2 BEE BEE contributor contributor NOSA

45

PIPES, PUMPS & VALVES

Pipeline flexibility Rigid pipes made from materials like concrete and steel provide good static per formance; however, there are many cases where pipes made from thermoplastic materials offer significant advantages.

S

tudies have proved that sewer and water pipeline networks function optimally when the total installed system is composed of high-density polyethylene (HDPE) elements.

These typically consist of pipes, gaskets, sleeves and allied components, such as manholes.

Southern Pipeline Contractors (SPC) has further refined the process through the design and development of its series of HDPE corrugated pipes, which add further flexibility during installation.

Lightweight, easy to handle and lay, SPC’s pipes are durable, versatile and virtually maintenance-free over their lifetime.

This is especially important in highly corrosive environments.

Key SPC products in this series include the Magnum and Big-Dren ranges.

Magnum caters for sewer and stormwater applications across an external diameter spectrum from 160 mm to a maximum of 1 200 mm. In turn, Big-Dren is a specialised drainage pipe fielded in three internaldiameter options of 200 mm, 250 mm and 350 mm respectively, as well as the standard sizes of 75 mm, 110 mm and

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IMIESA February 2020

160 mm, all available in 6 m lengths plus 50 m coils.

Big-Dren is a flexible, double-wall, corrugated HDPE pipe manufactured with the continuous co-extrusion of both walls, with slots arranged at 60-degree intervals around the circumference. Slotted piping represents the most effective and economical solution for areas with major hydrogeological instability. They are also well suited for foundation drainage on construction sites, fluid capture within a landfill environment, and for roads and stormwater run-off.

Concrete vs HDPE “Since introducing the SPC range to the South African market, we’ve been instrumental in supplying stormwater and sewer projects nationally,” says SPC’s Yougesh Mohun. “A key deciding factor has been the decision to opt for HDPE in place of concrete pipes, based on mathematical calculations.”

The crush resistance for Magnum pipes is 8 KN/m2, underscoring the exceptional strength of HDPE materials. Magnum products also have a resistance to abrasion that is up to five times greater than that of concrete pipes.

“Where concrete pipes exhibit low resistance to abrasion, a progressive reduction in wall thickness increases the tension and decreases the useful life,” Mohun explains. “In comparison, and thanks to their low elasticity module and reduced roughness, HDPE pipes have an elevated abrasion resistance and hydraulic performance. Despite having a smaller internal diameter, SPC corrugated pipes achieve a higher hydraulic performance than concrete pipes with matching DN specifications.”

In a recent project example, the client’s engineer opted for ID 300 mm corrugated pipes instead of DN 350 mm concrete.

The chief reasons were the construction and installation savings in terms of time and cost, as well as improved stability of the surrounding ground due to Magnum’s watertight joints. The latter minimise the eventuality of leaks, plus the penetration of tree roots, resulting in blockages.

In another instance, the consulting engineers on an N3 toll road upgrade project specified SPC’s Magnum corrugated pipe for designated stormwater installations.

The deciding factors were the performance benefits of corrugated HDPE compared to both concrete and smooth PVC pipe.

The corrugations enabled the pipe to be successfully anchored into the ground, simplifying work for the contractor.

“Considering the whole picture, opting for a concrete pipe network may lead to higher costs connected to the installation and maintenance, as well as the comparable lower life expectancy of the system – aspects often underrated in design stages. On the other hand, HDPE piping systems achieve a much higher longer-term return on investment, as well as a higher degree of reliability over the years,” Mohun concludes.

Where some see obstacles, we see opportunities For engineering innovation, you need a true cross-over company

We thrive on challenges. They keep us innovative and on the cutting edge of our industry.

Proudly South African, JG Afrika provides civil and structural engineering and environmental consulting services throughout Africa.

SIKHULISA SONKE • WE DEVELOP TOGETHER

www.jgafrika.com

PIPES, PUMPS & VALVES

Innovative replacement solution In having reached the end of its life, an innovative solution was needed to replace a 3.5 km, 1 000 mm diameter, steel treated process water pipe at Sappi’s Tugela Mill.

T 48

he Sappi Tugela Mill is one of the company’s oldest purposebuilt mills producing container board and lignosulfonate for

IMIESA February 2020

local and export customers. A pipeline conveying treated process water from the mill to a dedicated discharge point on the Tugela River needed replacing, as it had reached the end of its design life and was showing signs of fatigue and potential failure due to degradation of the steel pipe wall.

In April 2018, Sappi went out to tender for the replacement of the pipeline.

The replacement pipeline needed to be constructed not more than 3 m from the existing pipeline and all works were to remain within the provided 8 m servitude.

The existing pipe needed to remain in operation until the new installation was complete, and all route markers, manholes and related structures were to be reinstated as part of the project.

The tender was awarded to JG Afrika, who appointed Leomat Construction as the main contractor.

An innovative solution The existing 1 000 mm diameter pipeline runs underground from the mill, through the town of Mandini and alongside the Mandeni stream before discharging into the river. The mill has the capacity to store its treated process water for nine hours, creating a buffer in which tie-in work could be done.

The new replacement project needed to minimise public inconvenience, while presenting an innovative, cost-effective, quality, efficient solution that also reduces environmental risk.

Sappi requested the use of HDPE for the new pipeline because the material is more

PIPES, PUMPS & VALVES

resilient to corrosion and chemical attack than the existing carbon steel pipe. The biggest advantage of HDPE is its flexibility and toughness, which led to JG Afrika’s design proposal of a two-phased solution.

Phase one – an emergency intervention – involved laying the HDPE pipeline above ground from the mill to the discharge point.

This pipeline would be within the 8 m allowed servitude. This solution provided a quick way to mitigate environmental and reputational risk.

The HDPE sections were butt-welded to allow for quick laying and early commissioning of this emergency intervention. The aboveground pipeline was active and running safely within six months of the tender award.

Phase two provided a long-term solution.

While the above-ground pipeline was operational, a new trench was excavated along the alignment of the existing steel pipeline. The old steel pipe was removed from site by Leomat and sent for recycling/ disposal. The above-ground pipeline was lifted into the existing trench during three- to four-hour shutdowns at the mill. The pipe was replaced in its final position for the road crossings.

Appropriate bedding was installed at the base of the trench before the replacement HDPE pipe was placed in sections and the trench backfilled. As the alignment remained unchanged, it could be safely assumed that there would be no hard rock in the trench.

This two-phased solution allowed for the faster commencement of works, mitigating the risks of excavation near the operational steel pipeline, while remaining within the 8 m servitude.

Overcoming challenges The project involved four road crossings and the Mandeni stream crossing. The road crossings were completed during the emergency phase, in their final long-term position.

At the crossing point at Old Main Road, the team found boulders in the existing pipe, preventing them from sleeving through the pipe with the new HDPE line. In one of the project’s biggest challenges, the team removed the existing steel pipeline and fed the new HDPE line through the existing concrete sleeve. The pipe was then welded to the above-ground pipeline on either side of the road in a single nine-hour shutdown.

When crossing the Mandeni stream, the design methodology included the temporary pipeline being strapped to the existing weir to allow for the weir to be broken open and the existing pipe removed. This daring and difficult solution was considered a design and construction feat.

Unusual pipe size With a treated process water outflow of 50 Mℓ/day, the new pipe needed to be 800 mm in diameter.

Pipelines of this diameter are not common in the water engineering field, and are generally only found in bulk water and sewage operations. This project not only made use of an uncommonly largediameter pipeline but adopted a unique methodology that used the best properties of the material of choice, HDPE, in an innovative and risk-averse way.

HDPE is incredibly workable, flexible and tough, which enabled the team to double-handle the pipes in the two-phased approach. The design and construct approach also ensured that the contractor’s wealth of knowledge and expertise of construction techniques and efficiencies would be introduced during the design phases of the project by the engineer.

The innovative approach adopted in this project resulted in it receiving a Highly Commended Award for Technical Excellence at the 2019 PPS-SAICE Awards.

IMIESA February 2020

49

THOUGHT LEADERSHIP

Engineers with a social conscience South Africa’s civil engineers are critical to the process of enabling the infrastructure that drives our economy.

Beyond that is the need to address social imbalances. Kibiti Ntshumaelo, managing director, Lekwa Consulting Engineers, talks to IMIESA about the way forward for future practitioners.

T

he South African Institution of Civil Engineering recently conferred Ntshumaelo with the National Institution Awards 2019 – Engineer of the Year award, an exceptional achievement that recognises his commitment to the profession. This is particularly evident in his motivation and mentorship of young technicians, technologists and engineers preparing for professional registration with the Engineering Council of South Africa (ECSA). He says bridging the experiential gap between the older generation and new, up and coming candidates is a critical part of South Africa’s future success.

Echoing Ntshumaelo's personal role as a registered mentor, Lekwa is a ‘Commitment

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IMIESA February 2020

and Undertaking’ organisation that trains technicians, technologists and engineers in line with ECSA requirements. Lekwa also takes students on-board so they can complete their practical training phase, as well as those needing to complete internships and learnerships.

Ntshumaelo has recently formed a new company, The Enguineer. This training academy addresses the needs of students who completed neither the S4 course to gain the old National Diploma nor the old BTech qualification. From 2019, all aspiring technicians and technologists who did not qualify under the previous system will have to complete the new four-year Advanced Diploma in Civil Engineering at universities of technology in order to be upwardly mobile.

“I’ve been a professional civil engineer for over 21 years. During that time, the profession has evolved significantly with the advent of developments like advanced software, virtual reality, artificial intelligence and machine

learning such as drone technology pushing the boundaries of construction and design,” says Ntshumaelo. “One thing we can be certain of is that the role of technology will continue to shape the way we engineer now and in the future.”

For South Africa to succeed, a key part of the process will hinge on visionary engineers, working alongside other built environment professionals. “For this reason, South Africa definitely needs to increase the number of school learners studying and passing maths and science up to matric level, while exploring various routes for entry requirements to the construction sector, including artisan apprenticeship training,” he continues.

The changing landscape Every country has its own set of challenges – a key one for South Africa being entrenched in the apartheid spatial planning that separated communities. To this day, segregated planning continues to be a burning issue, but one that Ntshumaelo believes is being addressed by new thoughts on inclusionary and sustainable mixed-use smart developments that are also influencing how civil engineers engage with community projects.

“For me, one of the major game changers is the way we address the economic class segments of our societies, in creating an integrated development model that eliminates our unique and devastating 40/40/40 reality model, a legacy of the pre-1994 era,” he continues. “In terms of this model, a high percentage of South Africa’s workforce live in a 40 m2 house, approximately more than 40 km from their workplace, and thus spend around 40% of their disposable income on commuting.

That model is obviously not sustainable, and hence requires a shift in thinking towards inclusionary housing.”

Leading by example Putting theory into practice, Lekwa has received numerous awards for excellence in the turnkey execution of human settlements projects, from installing underground services to the building of housing structures. These include the Nellmapius Extension 22 township development in the City of Tshwane, which won Bronze in the Sustainable Development category at the Gauteng Premier Service Excellence Awards 2017. Lekwa is currently completing the electrification phase.

Outside South Africa, and in parallel with its local focus, Lekwa is taking its model to the broader African market, where there is major demand for housing and associated infrastructure, which Ntshumaelo refers to as “lively neighbourhoods”, where residents and businesses interconnect.

Going forward, and in support of the South African government’s vision, he says that we need to see far more inclusionary housing projects being rolled out locally, particularly given the rapid rate of urbanisation. Lowerincome workers need to be closer to their employers, and that equally applies to their children, who need access to schools much closer to home.

“Developers in more affluent areas need to make provision for this by allocating space for lower-cost rental and rent-to-buy housing alongside the upmarket mixed-use projects we see mushrooming within South Africa’s major cities,” he asserts.

“That’s a major part of our mandate going forward, either in terms of our own property development projects or when working in conjunction with another developer. Where practical, designs should focus on high-rise apartments to optimise land use, particularly in high-density areas like Sandton’s Alexandra township, where the clash between formal and informal settlements needs urgent unbundling and restructuring,” Ntshumaelo adds.

“The upside is that revitalised zones create new employment and lifestyle opportunities.

However, they can only work if there’s buy-in from all property owners. There needs to be a sharing of responsibility and a genuine desire to effect meaningful social and economic change. That’s the key message I drive home to my engineering candidates and staff,” Ntshumaelo concludes.

ENERGY

Cape Town fights to procure from IPPs The City of Cape Town is fighting for permission to buy energy directly from independent power producers (IPPs) in order to protect against the devastating effects of load-shedding.

T

he City of Cape Town is seeking permission from the Judge President of the Gauteng High Court for an expedited hearing on its section 34 request to procure electricity directly from IPPs. Late last year, Minister of Mineral Resources and Energy Gwede Mantashe issued a call for immediate measures to ensure energy supply for the countr y, including the promulgation of section 34 determinations.

Following this, Cape Town’s acting executive mayor at the time, Alderman Ian Neilson, stated that, if the minister were serious about implementing immediate measures, he would agree to the city’s request to purchase energy from IPPs. “We need immediate action now and Minister Gwede Mantashe needs to show leadership and put the well-being of South Africans and our economy first,” said Neilson.

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IMIESA February 2020

Currently, the hearing is scheduled to take place in May 2020.

President Cyril Ramaphosa has since proclaimed a new era of self-generation, stating that the uncer tainties and inconsistencies currently inhibiting businesses and households from selfgeneration will be removed.

He added that government was ready to embrace self-generation as part of the solution addressing South Africa’s electricity deficit. However, it remains unclear how or when government will facilitate selfgeneration and whether this will apply to municipalities such as Cape Town.

Ongoing battle Cape Town’s battle to procure energy directly from IPPs is not a new one. In 2015, the City of Cape Town wrote to the Minister of Energy at the time, Tina Joemat-Pettersson, requesting a section 34 determination. This would allow the city to procure 150 MW of

solar energy and 280 MW of wind energy from IPPs. Since 2015, the city has regularly written to successive ministers and has now turned to the courts, seeking a declaration that a determination by the Minister of Energy is not required for an IPP to produce and sell electricity to the City of Cape Town.

“NERSA and the Department of Mineral Resources and Energy should seize the opportunity to reach an agreement on the legal framework to allow for the issuing of purchasing licences to the city and other municipalities.

“Should they reach an agreement on this before the proposed original date for the hearing, it will not only enable the city to move forward with its plans sooner but will also mean that litigation in this matter is not required,” said Neilson.

“There can be no doubt that this is a matter of urgent national and local importance.”

ENERGY South Africa is in the early stage of this transition and the next five years are critical to demonstrate intention, ensure stability, and gather international and local support in a rapidly transitioning energy environment.”

Economic woes Many Cape Town companies have reported significant financial losses as a result of load-shedding and the hospitality and tourism industries are being compromised.

The tourism sector is responsible for thousands of jobs in Cape Town, with over 1.2 million international visitors annually bringing in approximately R15 billion in tourism revenue. The impact of loadshedding on the sector can, therefore, not be understated.

Promoting a green economy Renewable energy technologies can offer rapid energy solutions due to shorter lead times. James Vos, MEC: Economic Oppor tunity and Asset Management, City of Cape Town, argues that the green economy employs thousands, has the potential for further growth and can provide

a sustainable solution to the electricity generation problems.

Vos believes that the applicability of a single energy utility model is changing rapidly in a global context with the introduction of new technologies, which are cheaper, flexible, capable of being decentralised, and more environmentally friendly.

Vos also calls for consistent regulatory frameworks that support and enable a fair, open and efficient energy market. He believes this will assist in alleviating the burden that a struggling Eskom places on South Africa’s economic growth. He has thrown his full support behind the city’s application, stating that it is vital for improving Cape Town’s energy security.

Market opportunities South Africa’s internationally lauded

Renewable Energy Independent Power Producers Procurement Programme has resulted in a blossoming renewable energy market, which has exploded over the last several years. To date, the programme has attracted more than R200 billion in investment, of which R48.7 billion is foreign equity and financing activities.

The 2018 Integrated Resource Plan calls for 8 100 MW wind, 5 670 MW solar photovoltaic and 2 400 MW small-scale embedded generation to be procured by 2030. According to GreenCape’s Utilityscale renewable energy 2019 Market Intelligence Report, this offers the potential of attracting in excess of R200 billion in the next 12 years.

The report states that the Department of Energy has set the foundation for South Africa to become a global leader in transitioning to renewable energy, and a technology and innovation hub for the continent.

Vos concludes, “South Africa is in the early stage of this transition and the next five years are critical to demonstrate intention, ensure stability, and gather international and local support in a rapidly transitioning energy environment.”

IMIESA February 2020

53

VEHICLES & EQUIPMENT

Leading range of cut-off saws

Global leader in cut-off saws STIHL has developed a range of leading products. IMIESA speaks to Werner Nuss, export and business development manager, STIHL SA, about the innovative TS range of cut-off saws.

What makes this range stand out?

WN These are world-class products used widely in countries such as the UK where construction is governed by strict regulations in terms of site and user safety.

This range is designed to meet these tightly monitored environmental and legislative demands and naturally meet the quality and performance expected from any other STIHL product.

Tell us about your range of cut-off saws.

The individual products have specific features that make them unique, and are backed up with the design, quality and service offered by STIHL. TSA 230: The world’s first batteryoperated cut-off saw with a 230 mm cutting blade, the TSA 230 is compact and lightweight and offers optimum manoeuvrability and versatility. It can be used indoors or outdoors due to the innovative design that allows for the attachment of an optional vacuum adapter, or the standard-fitted water connection, which can be attached to a hosepipe (or pressurised water container) to limit dust and reduce operator exposure to harmful particles. The TSA 230 is ideal for mining, roofing, paving and tiling contractors.

TS 500i: Another world first, this cutoff saw with electronically controlled

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IMIESA February 2020

fuel injection ensures smooth running and impressive fuel consumption. An anti-vibration system offers greater user comfort, together with reduced emissions.

A standard-fitted water connection supplies the 350 mm cutting wheel with water for wet cutting, effectively limiting the amount of dust produced while cutting. The longlife air filter system with cyclone air routing ensures an extended filter service life. The TS 500i is perfect when the operator wants phenomenal performance and convenience in challenging industrial construction sites.

TS 440: The world’s first cut-off saw with sensor-activated Quickstop wheel brake technology, the TS 440 is designed for cutting in hard-to-reach areas such as corners where the guard positions on traditional cut-off machines make cutting difficult. The guard on the TS 440 has been adjusted to expose the top portion of the wheel for work-anywhere flexibility.

This expanded guard adjustability is made possible by the Quickstop wheel brake technology, which stops the wheel rotating in fractions of a second if kickback occurs.

Other features include a top handle for well-balanced handling and increased manoeuvrability and an electronic water control for easy and efficient water flow adjustment while cutting. The water flow automatically stops at idle speed and

Werner Nuss, export and business development manager, STIHL SA

restarts when the throttle is engaged. The TS 440 is well suited for work on-site, where safety is the biggest factor with the reduced kickback and Quickstop technology.

What are the main benefits for users?

The main benefits are the enhanced safety and ergonomic design features that make them easy and comfortable to operate.

This is enhanced by the availability and service backup provided by STIHL and its nationwide network of specialist dealers.

Cut-off saws aren’t currently common in South Africa, but are very widely used the world over, and STIHL is a leader in this range in very exacting and regulated markets, such as the UK and Europe.

Our range is developed to meet these countries’ strict regulations. Although such requirements are not yet enforced locally, we hope that the local market will understand that the TS range offers outstanding advantages in terms of performance and enhanced user safety and comfort.

PROFESSIONAL AFFILIATES AECOM siphokuhle.dlamini@aecom.com Afri-Infra Group (Pty) Ltd banie@afri-infra.com Alake Consulting Engineers lunga@alakeconsulting.com ALULA (Pty) Ltd info@alulawater.co.za AQUADAM (Pty) Ltd sales@aquadam.co.za Asla Construction (Pty) Ltd johanv@asla.co.za Aurecon Fani.Xaba@aurecongroup.com Aveng Manufacturing Infraset werner.booyens@infraset.com Averda claude.marais@averda.com Bigen Africa Group Holdings otto.scharfetter@bigenafrica.com BMK Group brian@bmkgroup.co.za Bosch Munitech info@boschmunitech.co.za Bosch Projects (Pty) Ltd mail@boschprojects.co.za BVI Consulting Engineers marketing@bviho.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 DPI Plastics Farhana@dpiplastics.co.za EFG Engineers eric@efgeng.co.za Elster Kent Metering Mark.Shamley@Honeywell.com 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 Hydro-comp Enterprises info@edams.co.za I@Consulting info@iaconsulting.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@ctokamteys.co.za Kitso Botlhale Consulting Engineers info@kitsobce.co.za Lektratek Water general@lwt.co.za Lithon Project Consultants (Pty) Ltd info@lithon.com Makhaotse Narasimulu & Associates mmakhaotse@mna-sa.co.za Malani Padayachee & Associates (Pty) Ltd admin@mpa.co.za M & C Consulting Engineers (Pty) Ltd info@mcconsulting.co.za Maragela Consulting Engineers admin@maragelaconsulting.co.za Mariswe (Pty) Ltd neshniec@mariswe.com

Martin & East gbyron@martin-east.co.za Mhiduve adminpotch@mhiduve.co.za Mogoba Maphuthi & Associates (Pty) Ltd admin@mmaholdings.co.za Moedi Wa Batho Consulting Engineers (Pty) Ltd info@wabatho.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 Ribicon Consulting Group (Pty) Ltd info@ribicon.co.za Royal HaskoningDHV francisg@rhdv.com SABITA info@sabita.co.za SAFRIPOL mberry@safripol.com SALGA info@salga.org.za 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 SiVEST SA garths@sivest.co.za Sizabantu Piping Systems (Pty) Ltd gregl@sizabantupipingsystems.com SKYV Consulting Engineers (Pty) Ltd kamesh@skyv.co.za SMEC capetown@smec.com Sobek Engineering gen@sobek.co.za Southern African Society for Trenchless Technology director@sasst.org.za Southern Pipeline Contractors (Pty) Ltd spc@vinci-construction.com SRK Consulting jomar@srk.co.za 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 Ulozolo Engineers CC admin@ulozolo.co.za V3 Consulting Engineers (Pty) Ltd info@v3consulting.co.za Vetasi south-africa@vetasi.com VIP Consulting Engineers esme@vipconsulting.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 Water Solutions Southern Africa ecoetzer@wssa.co.za Wilo South Africa marketingsa@wilo.co.za WRP ronniem@wrp.co.za WRNA washy@wrnyabeze.com WSP Group Africa ansia.meyer@wsp.com

I M E S A A F F I L I AT E M E M B E R S

IMESA

VEHICLES & EQUIPMENT

Bell concludes new BBBEE structures A Bell grader deployed on a road project in Swaziland

H

eavy equipment manufacturer and distributer Bell Equipment has concluded a BBBEE agreement that will empower the group’s South African manufacturing subsidiary, Bell Equipment Company South Africa (BECSA), and further empower sales and distribution subsidiary Bell Equipment Sales South Africa (BESSA).

Commenting on the empowerment transaction, Leon Goosen, group CEO, Bell Equipment, said both BECSA and BESSA will be 51% black-owned and aligned with government’s economic transformation policies. This will improve

the BBBEE scorecards of both entities and position the group more competitively in the South African market.

“BECSA, as a 51% black-owned entity, will benefit from continued access to Automotive Production and Development Programme funding, the ability to increase manufacturing throughput and encourage the drive for greater industrialisation. We estimate BECSA will achieve a Level 3 BBBEE recognition,” explained Goosen.

A black management company – comprising current Bell executives Avishkar Goordeen, Dominic Chinnappen, Duncan Mashika, Bruce Ndlela and Niraj Andhee – as well as the Bell Foundation

will hold an effective 36% share in BECSA and a 21% share in BESSA.

Restructuring for empowerment To accommodate the empowerment transaction, it was necessar y to restructure the organisation and Bell Equipment SA Holdings has been formed as a holding company through which both BECSA and BESSA will be owned.

All the group functions, and functions associated with being an original equipment manufacturer, will reside in a new company known as Bell Equipment Group Services (BEGS), which will be 100% owned by Bell Equipment Limited.

INDEX TO ADVERTISERS

56

AfriSam

12

Circuit Water Engineering

African Energy Indaba

53

ELB Equipment

Andreas Stihl

19

IMESA

A-OSH Expo

20

JG Afrika

47

APE Pumps

33

Lafarge

IFC

Aquatan

34

NOSA

CESA

11

Rocla

IMIESA February 2020

OBC 51 2, 4, 55

Quality Filtration Systems Shisalanga Sika Sizabantu Piping Systems

23 OFC 44 IBC

SMEC

16

45

Structa Group

29

42

Technicrete

43

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Water can be pumped into the system, or should the location allow, be fed by gravity.

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