Monthly Archives: July 2021

Client Focus

READYMIX QUALITY KEY TO CONSTRUCTION SUCCESS

It is no surprise that cost cutting is the order of the day in the construction sector, but this should not prevent contractors from ensuring that their readymix concrete is up to scratch.

“The manufacture and supply of readymix needs to meet not just customer expectations, but also a range of regulated standards,” says Amit Dawneerangen, construction materials general manager for sales and product technical at AfriSam. “Our experience at AfriSam – where we are regularly asked to step in where a supplier has failed to meet obligations – suggests that it is time to go back to basics.”

The basics in the readymix sector, says Dawneerangen, involves an intricate balance of meeting South African National Standards (SANS), while delivering product at a competitive cost. These SANS requirements cover the manufacture of readymix, and the properties of the input materials. Complying with these standards implies that readymix providers have the necessary systems in place and equipment installed for accurate monitoring of concrete performance. 

He notes that South Africa has, over the past two decades, moved away from on-site batching towards greater use of readymix which can be produced at larger, centralised plants under highly controlled conditions. This gives contractors better assurance of quality levels, and allows the evolution of specialised and complex concrete mixes for challenging applications.

“The sophisticated technology used by many South African readymix producers underpins their compliance with the necessary standards,” he says. “For instance, there needs to be accurate weighing equipment in the batching plant, and systems to alert management if tolerances are breeched.”

This equipment must be calibrated regularly – internally and externally – to ensure accuracy. The standard SANS 878 specifies the tolerances within which the manufacturing and application of readymix must take place. For cement itself, there is SANS 50197 which applies, while standards for aggregate and sand are governed by SANS 1083.

Dawneerangen points to the growing number of ‘independent’ readymix companies who are not formally linked to the producers of construction materials like cement and aggregate. The difficult conditions which have prevailed recently in the construction sector has made it difficult for many to sustain themselves and cost cutting is affecting product quality. 

He emphasises that contractors need to carefully examine the quality systems in place at any prospective readymix provider before finalising procurement contracts. Without the assurance that these systems are being effectively applied, a contractor can expose their projects – and their business as a whole – to a range of serious risks. 

Client Focus

DATA CENTRE SURGE DEMANDS MORE DRY-TYPE TRANSFORMERS

Noting a marked increase in the demand for dry-type transformers for data centres being built in South Africa, Trafo Power Solutions will supply four 1600 kVA units to yet another data centre in Gauteng.

The country is benefiting from a wave of data centre investments in African countries including Kenya and Nigeria, according to a recent Standard Bank report. The trend is driven by advances in connectivity and data consumption, as smartphone use on the continent grows rapidly. Download speeds are rising which, in turn, boosts data consumption. There is also a global shift – driven by factors like data protection regulations – towards hosting data closer to where it is ultimately consumed.

Trafo Power Solutions managing director David Claassen highlights that data centres are energy-intensive, and need high levels of electrical power. In this context, the appropriate transformers with requisite protection devices are vital to support applications as robust as these. 

“Dry-type transformers are ideal for data centres, especially from a safety, reliability and environmental perspective,” says Claassen. “In addition, the load characteristics need to be considered. To suit the high percentage of non-linear or harmonic load, for instance, these transformers have a design K-factor of 13.”

The units were manufactured to the highest level of quality by TMC, a leading Italian transformer OEM, with whom Trafo Power Solutions has partnered to bring dry-type transformers to the African continent. These low-loss transformers conform to the European Directive EU 548-2014, providing considerable savings in energy consumption. An electrostatic shield is an important element of the design, diverting leakage currents to ground. 

“With our experience in dry-type transformer installations around Africa, Trafo Power Solutions are well equipped to assess the application requirement in data centres,” Claassen says. “In conjunction with our manufacturing partner, we can design and deliver a fast-track solution to meet the end-user’s specific needs.”

It is likely that new undersea cables to Africa will continue to raise broadband capacity, driving the trend for more data centres to be established locally.

Client Focus

CONCOR’S INNOVATIVE PAARL ROCK SHOWS THE WAY

Construction is underway at Paarl Rock, the fifth building in Concor’s 22-hectare Conradie Park development in Cape Town.

Piling for the eight-storey block began in May 2021, marking the start of a one-year building programme, according to Mark Schonrock, property development manager at Concor. Paarl Rock will comprise 266 architecturally designed apartments in an affordable model for first-time home owners. 

The block is underpinned by 158 continuous flight auger (CFA) piles, which present a quicker solution than bored or driven piles. With depths of 8 to 11 metres, the piles could be completed in just three weeks, Schonrock says, improving the pace of the project. 

“We have also installed two tower cranes – a 55 metre jib and a 45 metre jib – to facilitate our programme of work,” he says. These will lift and move concrete for vertical columns, as well as reinforcing bars for slabs and columns, and all formwork around the site.

Horizontal concrete slabs will all be post-tensioned, a current efficiency trend which reduces the amount of costly rebar required. The planned slab thickness has also been slightly reduced, from 285 mm to 255 mm. While a relatively small reduction, this will allow a saving of some 450 m3 of concrete over the planned area of 15,000 m2 of slab work.

“Pouring of slabs will be conducted by a truck-mounted boom placer, which enhances construction efficiency especially where large continuous pours of 200 to 220 m3 are required on this project,” he says.

The Paarl Rock block will include ground floor retail space, two lifts and a roof top deck on the sixth floor looking westwards at Devil’s Peak and over the Cape Town central business district towards Signal Hill. To minimise the cost of long-term maintenance on the outside walls, the design makes use of face brick – but with a difference. 

“Different colours and shapes of face brick have been specified to create texture and variety in the façade,” he explains. “Patterns are also created with rustication, using bricks of different shapes or with varied orientation.”

A perforated design is also used for the brick walls in front of drying yards, letting through light and air while also giving an attractive texture to the building façade. The laying of face bricks requires a somewhat elevated level of skill and attention, and also takes longer, so the best artisans are put onto the rustication work.

Schonrock notes that Cape Town still offers a good pool of bricklaying skills, but the long period of depressed conditions in the sector is going to be felt in skills supply as building activity improves. As part of its corporate contribution to skills development, Concor conducts a range of training on its Conradie Park site. 

“Through the National Youth Service programme, for instance, we are training six local bricklayer learners,” he says. “Beginning in November 2020, they completed a six-month training course and were then placed with selected sub-contractors to work on the current project.”

Paarl Rock’s innovations include an energy-efficient hot water system for residents, lowering their cost of living and taking load off the national grid. 

A centralised hot water generation system on the ground floor raises the upfront cost but provides many long-term benefits to users. An on-roof solar generator will assist in ‘over-heating’ water during the day in a specially-designed storage vessel to around 85 to 90 C. 

“Tapping into off-grid power in this way means that residents can save on what they pay in water-heating bills,” he says. 

The development is also conserving water and reducing water costs by supplying its own irrigation needs from a master incoming line of treated effluent – at just five to 10% of the cost of potable water. The water quality from this line, which is clean enough to be discharged into river systems, is further treated on site and also used for all irrigation and cleaning purposes.

Concor has been on site at Conradie Park – where the old Conradie government hospital closed about a decade ago – for about two and a half years, preparing the infrastructure for the developments. 

Roads have been installed, along with stormwater drains and a dedicated sewage reticulation system. A pump station was installed to move sewage over the Elsie’s River canal to the main Athlone sewer system and three new electrical substations were constructed.

The Conradie Better Living model is one of seven ‘game changer’ projects which has been prioritised by the Western Cape Government. This aims to improve the lives of citizens through the Finance Linked Individual Subsidy Programme, providing affordable housing situated near the city’s main arterial routes and job opportunities.

Client Focus

CLEVER SOLUTIONS, RIGHT EQUIPMENT SAVES RE-MINING PROJECT

When a project to re-mine stockpiles at a large iron ore operation discovered its planning assumptions had been too optimistic, Pilot Crushtec was able to save the day with its experience and its ready fleet of Metso crushing equipment.

The plan was initially to feed natural fines – less than 8 mm in size – from run-of-mine (ROM) stockpiles to the smelter, later introducing a mobile jaw crusher and then mobile cone crushers with a sizing screen. It was found, however, that the portion of fines in the stockpile was much less than expected, putting the whole project in jeopardy. 

To rescue the situation, a fully mobile three-stage crushing and screening plant was urgently required to meet the required tonnages. Crushing and screening specialist Pilot Crushtec, who is also the local distributor of Metso equipment, had the answer and was able to deploy the necessary equipment on site within a few weeks. This included a Metso Lokotrack LT106 mobile jaw crusher, two mobile cones crushers – a Metso Lokotrack LT200HP standard and an LT200HP Short Head – and a Metso Lokotrack ST4.8 triple-deck mobile screen.

This was not the end of the challenges, though, as it soon became apparent that the concentration of iron within the stockpiled ore was lower than believed. Fortunately, the natural fines were richer than anticipated, presenting the opportunity of blending them with the lower-grade crushed ore. Here the Metso ST2.8 screen proved to be the key, with its two-way split providing a consistent supply of iron-rich natural fines to be blended with the stockpiles where required. 

The next step was to find ways of improving production of minus 8 mm material, although the 150 tonnes per hour being achieved was already regarded as good. With Pilot Crushtec’s experience, supported by Metso’s Bruno simulation software, a further increase of 10 to 15% was targeted. The strategy involved a range of complex ‘tweaks’ including an optimised liner profile, a change in screening media and apertures, and splitting the process train. 

This delivered the production target, with better continuity in the process while ensuring that the first two stages of crushing were not constrained by bottlenecks in the tertiary crushing and screening stage. This also reduced fuel and wear costs, as the equipment in the first half of the train could produce the same amount of material in fewer hours. 

Client Focus

EASTERN CAPE ROAD GETS STABILISED BY AFRISAM CEMENT

AfriSam’s specialised Roadstab cement is helping pave the way for a safer R67/5 road between Queenstown and Whittlesea in the Eastern Cape. 

The contractor – the Raubex Construction and Roadmac Surfacing Cape Joint Venture (RBX / RMSC JV) project – will consume around 180,000 bags of AfriSam’s Roadstab cement for the stabilisation of the road’s G4 sub-base layer. The contract covers 18 km of roadway on the R67/5 route, from the Swart Kei River bridge in the south to Queenstown in the north. 

A complete rehabilitation is underway which will see the road upgraded and widened. The road’s existing three metre per lane will be widened to 3,7 metre per lane, plus a 3 metre surfaced shoulder and rounding off on each side. Some vertical realignment is taking place, such as at those areas where drainage problems are addressed, where livestock crossings are required and at the new Swart Kei River bridge. This realignment will improve line of sight for motorists, allowing the authorities to raise the current 80 km/hr speed limit to 100 km/hr. 

About 700 m3 per day of material is moved to level out the road, allowing the contractors to get on timeously to the layer works – the lower selected and upper selected layers. These comprise an imported G5 crushed gravel material of 300 mm, which is compacted to 95% of modified AASHTO density. This is followed by a 300 mm thick G4 sub-base layer which is stabilised with AfriSam’s Roadstab cement product. 

The project’s stabilisation design requires a 3% portion of AfriSam Roadstab cement in the G4 sub-base. The 150 mm base layer is of G1 imported crushed stone, compacted to 88% of apparent relative density. The road is then completed with a surface of 20 mm Cape Seal with two slurries.

AfriSam ensures that the supply of road stabilising cement is ready and available when required, to support the scheduled roll-out of road construction activities. The Roadstab cement is trucked to site from AfriSam’s Queenstown depot, which is supplied by train line from the company’s Ulco factory in the Northern Cape. The nationwide footprint of AfriSam also allows it to service the project from its Bloemfontein depot, when necessary. 

The road project also includes the building of a new bridge over the Swart Kei River and the widening of the Klaas Smuts River Bridge. The project began in July last year and completion is scheduled for April 2023. 

Client Focus

NAFASI WATER INSTALLS GRUNDFOS PUMP IN NEW LIME SLAKER

A stainless steel Grundfos booster pump is at work in Nafasi Water’s recently commissioned lime-slaking facility in the Mpumalanga coal mining region. 

According to Nafasi Water chief strategy officer Ashton Drummond, the new facility serves an important mine water treatment plant in the area and will help the plant cut its operating costs.  

“Instead of transporting lime to site in its heavier form – as calcium hydroxide – we can now reduce delivery volumes by transporting calcium oxide and slaking it on site,” says Drummond. “The cost savings make for an attractive payback period for the investment in the lime-slaking reactor.”

Raymond Makgoga, associate sales engineer at Grundfos, says two Grundfos stainless steel end-suction pumps were supplied to the project – one for duty and one for standby.

“The stainless steel is an important requirement due to the corrosive nature of the permeate being pumped into the lime slaker,” says Makgoga. “Our Grundfos NB/NK stainless steel end-suction pumps are excellent solutions for industrial applications, including where pumping of aggressive media is required.”

The installed pump delivers 50 m3 per hour at a pressure of about 4.5 bar. He notes that the pump’s efficiency has been enhanced by an IE3 WEG motor rated at 15 kW. The WEG motor was also able to accommodate the plant’s requirement for 525 V input.

Nafasi Water’s plant treats mine-impacted water to a high level of quality, allowing it to be discharged back into the river system in compliance with environmental regulations. The quality of the water is, in fact, so good that it is also pumped to the local municipality as drinking water for the community. 

The company’s treatment plants apply its proprietary HiPRO™ technology (Hi recovery Precipitating Reverse Osmosis), allowing up to 99,5% water recovery from complex waters emanating from mining areas. 

The relationship between Nafasi Water and Grundfos goes back many years, says Drummond, with its water treatment plants making extensive use of Grundfos pumps. He notes that Grundfos is exceptionally competitive when responding to market requests for pump packages. Its wide range of pumping solutions also allows Grundfos to offer technically compliant solutions that meet customer needs.  

Client Focus

CONCOR POISED FOR GROWTH AS BETTER YEAR BEGINS

With 2021 heralding some long-awaited improvements for the construction sector, Concor is leveraging its new operating model to position itself for growth.

The pace of tender roll-out for civil infrastructure work has picked up this year, as have aspects of the building sector. The mining sector – Concor’s other key focus – has also seen a welcome change of fortunes in recent years.

According to Fezeka Nompumza, Concor’s executive for business development and stakeholder engagement, the company’s model going forward is a centralised operation that can optimise efficiencies, prioritise teamwork and facilitate cross-selling across its suite of services.

“This direction is underpinned by our values of teamwork, care, agility, delivery and trust,” says Nompumza. “These drive our proactive collaboration with clients as we build their faith in our hard-earned capabilities.”

This approach has already earned Concor a niche position in the renewable energy sector, she notes. The company has developed a significant speciality in wind farm developments, working with some of the leading players in South Africa’s Renewable Energy IPP Procurement Programme (REIPPPP). 

“This success is paving the way for ongoing wind farm involvement, but is also opening doors into other energy segments such as solar photovoltaic, gas to power and battery energy,” she says. “By building strong relationships, we have retained clients since the first round of the REIPPPP and are looking forward to how we can contribute to round five.”

Concor has also taken the initiative in the private building sector, which has been among the hardest hit by poor economic conditions exacerbated by the Covid-19 pandemic. It is pursuing its own property development plans, having initiated the exciting Conradie Park mixed-use project in Cape Town. A collaboration with the Western Cape government, this R3-billion development is creating 3,500 affordable new homes over a well-placed 22-hectare site in the suburbs. 

“We are proud to be setting some important trends that can promote inclusive development in South Africa, while building a leading black-owned contracting business,” she says.

Displaying its legacy of innovation, Concor’s recent and current projects signal its intent for the future. 

Using alternative building technology to build a 300-bed ICU unit at Jubilee Hospital, Concor was able to complete this entire turnkey project between July and November last year. In another high-profile venture, the company is in joint venture with Mota-Engil to construct Africa’s third-highest bridge over the Msikaba River – part of the N2 highway project in the Eastern Cape.

Client Focus

BOOYCO CXS PDS SPREADS WINGS INTO SOUTH AMERICA

South African proximity detection system (PDS) specialist Booyco Electronics has further extended its global reach with a recent contract to a surface gold mine in Chile. 

According to Anton Lourens, CEO of Booyco Electronics, over 50 of its market-leading Booyco CXS systems have been installed on vehicles and other machinery on the mine. The installations followed a demanding testing phase which confirmed the customer’s trust in the technology. The project was carried out in collaboration with Booyco Electronics’ distributor in the region – mining and industrial technology company Insucam. 

“South America is a key focus in our drive to open markets abroad, so we are excited about the take-up of our latest CXS offering in that region,” says Lourens. “Safety on site is always a core concern for mines, and we value the opportunity to help them ensure that all their teams get home safely at the end of every day.”

Carlos Pinto Reyes, business development and new technologies manager at Insucam, says the customer analysed several systems in the market, finding that the Booyco CXS gave them the greatest reliability. 

This latest generation offering is built on Booyco Electronics’ pioneering role in developing PDS solutions for over 15 years. Ongoing product improvement has allowed the company to continuously enhance its features and functionality, creating a best-in-class product.

“After the installation of the Booyco Electronics CXS systems, every operator on the mine is aware of the exact location of machines and their distance away,” says Pinto Reyes. “They are quickly alerted to any possibility of collision, as the system tracks the trajectory, speed and position of each machine. Operators also appreciate how intuitive the system is, while not overwhelming them with persistent sounds.”

He highlights that the Booyco Electronics CXS uses direct GPS signals from three constellations of satellites to determine spatial positions, so it is not reliant on the GPRS coverage used by mobile phones. This is an important advantage for mines located in remote areas without reliable GPRS signal.

Lourens emphasises that the success of Booyco Electronics has been based on its high level of support wherever its products are installed, through which it builds long-term relationships. 

“We therefore partner with credible companies like Insucam, with the requisite technical skills, resources and footprint to ensure the optimal performance of our PDS products,” he says. 

Insucam has over a decade of experience in systems to improve the operation of mining machinery, and serves customers in South American countries including Chile, Peru, Colombia and Mexico. 

The technology advances made by Booyco Electronics’ CXS solution elevates it from being a warning system only to being a fully-fledged collision avoidance system – avoiding collisions between vehicles or between pedestrians and vehicles. It therefore provides a comprehensive and integrated response to Level 7, Level 8 and Level 9 safety levels – as defined by the Earth Moving Equipment Safety Round Table (EMESRT).