Monthly Archives: January 2020

Client Focus

CONCOR BUILDINGS DOES IT AGAIN AT CONSTRUCTION WORLD BEST PROJECTS

Concor Buildings received industry recognition at Construction World’s 2019 Best Projects awards last night when the company scooped the winning place in the Building Contractors category with its Oxford Parks Phase 1 Project.

In addition to this, the project also received a Special Mention in the AfriSam Innovation Award for Sustainable Construction.

Rui Santos, managing director of Concor Buildings, says that the company has established a reputation for tackling complex projects and delivering these safely, on time and within budget.

The Oxford Parks Phase 1 Project comprises a super basement structure with five buildings of which the BPSA was the first to be completed. Significantly, Concor Buildings has been appointed to continue work on the balance of the structures in the precinct.

About the winning entry
The BPSA head office building, with its compelling triangular shape, is a celebration of inspired architectural design coupled with meticulous attention to detail during construction, creating a strong focus point in Rosebank, Johannesburg.

Constructed by Concor Buildings, the new GBCSA 4-Star Green-rated head office for BPSA is the first completed building in the Oxford Parks Precinct. The Oxford Parks Precinct was selected as a pilot project for the Green Building Council of South Africa to create a green precinct rating tool for public environment projects.

The site of this development is near the Rosebank Gautrain station giving priority to alternative transport systems thus potentially reducing environmental impact of the tenants and customers.

While the architectural team impressed with an iconic design, Concor Buildings’ construction team excelled with innovative solutions for the challenges they faced to deliver a quality structure on time and within budget.

Client Focus

SLURRYSUCKER HELPS FARMER SAVE WATER

A large Northern Cape farming operation recently moved to drip-irrigation to conserve water. This required cleaner water from its dams – a challenge that Integrated Pump Rental could help to solve.

Using its specialised SlurrySucker desilting solution, Integrated Pump Rental desilted the first of four dams to prove the concept to the customer. Less silt meant not only cleaner water, but higher storage capacity in the dam.

“The customer was so pleased with the result that they have asked us to tackle the other three dams as well,” says Ruaan Venter, rental development manager at Integrated Pump Rental. “Dirty water would have clogged their drip-irrigation pipes and prevented the whole system from working.”

Venter highlighted that this was the first time that the company’s robust SlurrySucker equipment had been used in an agricultural application.

“Our traditional focus is in the mining industry,” he says. “But our experience in removing silt from process ponds on mines was ideal for this work in the agricultural sector.”

In these applications, the SlurrySucker is mounted on a floating barge that is pulled back and forth across a dam. A dewatering pump feeds the surface water down to a dredge-head, which agitates the silt using seven bar of pressure through 16 nozzles. The thick, agitated material is then pumped out of the dam using a fit-for-purpose slurry pump.

One of the key advantages of the system is that it does not damage the clay lining or geomembrane that lines the dam. Previous efforts to desilt these dams had been conducted with tractor-loader-backhoes (TLBs) and this punctured the lining and was unsuccessful.

“We make sure that our agitation heads are operated at a suitable distance from the floor of the dam,” he says. “We also use specially designed hose floats to keep the hoses and electrical cables on the water surface. This avoids any possible damage caused by submerged hoses being dragged across liners.”

There was also vegetation rooted in the silt, which had the potential to clog the suction heads. With its extensive experience and product range, Integrated Pump Rental applied its vortex impeller solution to deal with this.

The efficiency of the SlurrySucker meant quick work. At 80 metres long, 25 metres wide and about two metres deep, a dam could be desilted in just one week. And this is despite a high slurry content of about 60%.

“Using one 37 kW submersible slurry pump on the barge, we were able to pump at about 250 cubic metres an hour through a six-inch pipeline,” says Venter. “This converted to between 50 and 60 dry tonnes an hour.”

He adds that the customer has also entered into a maintenance contract with Integrated Pump Rental to ensure that the dams are regularly desilted for optimal system efficiency.

Client Focus

REGULAR UPGRADES KEEP BENTLEY PARK AT FOREFRONT OF TRAINING

Further enhancements at the Murray & Roberts Training Academy (MRTA) training facility, Bentley Park, are keeping the organisation at the top of its game in mining skills development.

The extensive training infrastructure near Carletonville in Gauteng is constantly adding to its resources as the demand requires, according to Tony Pretorius, education, training and development executive at Murray & Roberts Cementation.

“Among our new facilities is an indexing wall on which drill rig operators can be trained to drill on a horizontal plane,” says Pretorius. “We are also constructing a new tunnel with a face wall on surface to teach miners how to take line and grade and accurately mark off a development end with laser technology.”

He highlights the value of the MRTA’s ‘blended learning’ approach, which makes the learning process more effective by including not just classroom lectures but also e-learning, virtual reality, bench modelling, simulations and integrated learning in a workplace mock-up.

The facility prepares trainees mainly for the hard-rock underground mining environment, in which Murray & Roberts Cementation is a leading contractor.

Other recently developed mock-up facilities at the site include a board-and-pillar layout constructed on surface, to facilitate practical, supervised training for most primary and secondary trackless activities. There is also a figure-of-eight surface roadway for LHD driver training, complete with brake-test slopes. The fleet of trackless vehicles used for training at MRTA includes LHDs, a drill rig, a bolter, a telescopic boom handler, a mechanical scaler and a mechanised shotcreting unit.

“The quality of our skills output – combined with the ongoing demand for entry-level skills by Murray & Roberts Cementation’s mining projects around the country – allow us to turn training into jobs,” he says. “In fact, we are creating hundreds of career opportunities for unemployed youth from communities near our operations.”

With grant-funding from the Mining Qualifications Authority, MRTA will this year train 176 young jobless learners in basic mining-related skills. Those who successfully complete the six-month programme will earn a Level 2 National Certificate in Health, Safety and Environment for Mining and Minerals. Most trainees – of which half are women – are taken up by Murray & Roberts Cementation’s contract mining operations, to begin exciting careers in the mining industry.

Client Focus

PROCESS PLANT OPTIMISATION REALISED WITH FLSMIDTH SMARTCYCLONE™

Process plant optimisation techniques have become a necessity for mines looking to maximise their operating performance by keeping costs low, throughput high and downtime to a minimum. FLSmidth’s automated SmartCyclone™ system is a solution that delivers in all three areas for cyclone circuits, a vital processing element in any plant.

FLSmidth’s SmartCyclone is a monitoring and control solution for reducing cyclone-related process deviations. It also improves cyclone overflow particle size distribution, predicts and controls cyclone maintenance schedules, and optimises closed-circuit grinding processes.

This equates to monitoring the performance of individual cyclones within a circuit in real time, preventing unplanned breakdowns from occurring and monitoring wear rates while ensuring the cyclones are operating optimally at all times. This translates into higher efficiencies in the plant and ultimately, higher profitability.

The SmartCyclone closed circuit grinding optimisation system combines a variety of FLSmidth patented technologies which includes the FLSmidth Krebs SmartCyclone wear detection sensor technology as well as the Krebs’ patented roping sensor technology with patent-pending wireless controller system. This technology immediately identifies if a cyclone is malfunctioning.

The closed circuit grinding optimisation system also incorporates FLSmidth’s ECS/ProcessExpert® process control software with a new patent-pending SmartWear™ cyclone maintenance algorithm. One of the largest benefits associated with this software is the ability to develop a uniform operation strategy that outlines the best way to run the plant. Once this strategy has been established, the necessity to train new operators is reduced.

Reducing or eliminating manual operation, which decreases the potential for human error, is in fact one of the overarching benefits of SmartCyclone.

FLSmidth has more recently enhanced its Krebs SmartCyclone system with wireless technology that
enhances installation simplicity by eliminating the need for individual nodes and the interconnecting cables between the sensors and nodes and associated controllers.

It utilises a central wireless controller that can handle up to 16 sensors per unit; providing real-time wireless detection and communication of roping and/or wear data. The new wireless controller unit is a handheld device that can be removed from its docking/charging station to sync the individual sensors. Once it’s removed, it goes into battery power mode and the user can walk to a desired sensor, activate it with a magnet; trigger and set the necessary operating parameters.

Client Focus

MOTOR SYSTEM EFFICIENCY HIGH ON GLOBAL AGENDA

With electric motors consuming almost 70% of industry’s energy, companies are always looking for better motor efficiencies. For many years, motor efficiency has been well defined; however, when driven by a variable speed drive (VSD), the VSD efficiency and the total efficiency of the VSD and the motor has not been well understood. For many years, motor efficiency has been well defined. Choosing the right product combination can also be more difficult as manufacturers’ data is not always easily comparable. This is where the international IEC61800-9 standard comes to the rescue, according to global motor and VSD manufacturer WEG.

The IEC61800-9 standard – based heavily on the previous EN 50598 standard – gives manufacturers a clear framework for grading a complete motor system. End-users can compare the overall efficiency of a manufacturer’s products, irrespective of design and component selection.

The IEC61800-9 standard uses the Extended Product (EP) approach. This considers the efficiency of the Motor System, which is comprised of the Motor, the Basic Drive Module (BDM), the Complete Drive Module (CDM). Together, these make up the Power Drives System (PDS), which also includes any switchgear and controls.

This terminology sounds confusing but is just a technical way to say: Switchgear + VSD + Motor. The efficiency levels are defined by considering eight different operating points, covering low to high speed and torque. The user can easily compare his application load and speed requirements to the motor system defined speed and torque points.

The EP approach employs a semi-analytical model to calculate the efficiency of each of the components at the operating points of the driven equipment. The calculations are also based on tested and verified values. This results in the most efficient component selection for the application.

Using this standard, the user may be assured that:
• A motor complies with the defined motor efficiency levels of IE1, IE2, IE3, IE4 or IE5;
• A VSD complies with VSD efficiency IE0, IE1 or IE2; and
• The manufacturer’s motor and VSD used in combination will meet or exceed a system energy standard of IES0, IES1 or IES2.

Using this EP approach, the European Commission expects the increasing use of more efficient systems to help achieve its targets for carbon dioxide (CO2) reduction. In line with these efforts, WEG VSDs and IE2 motors in combination achieve IES2. And significantly, WEG’s VSDs and IE3 efficient motors exceed the highest system levels of efficiency. Additionally, WEG has product lines that exceed even IE4 and IE5 classifications.

Recognising that global population growth and economic development is driving up energy demand around the world, the European Union has set stringent targets to reduce CO2 emissions. These aim to cut emissions by 40% by the year 2030. This means creating more renewable energy sources, and also increasing the energy efficiency of industrial systems. Studies suggest that almost half of global energy consumption comes from industry – followed by commercial and residential use.

The EC’s regulation 640/2009 already requires that all electric motors operated from a variable speed drive or inverter must adhere to a minimum of IE2 to be eligible for sale. Fixed-speed applications must meet a minimum of IE3 to comply.

Where a motor does not operate at its nominal torque and speed, the variable speed drive represents a significant opportunity for energy optimisation. In addition, the greater the range of speed variation results in a greater PDS efficiency. Using WEG’s IE2 motors with any WEG variable speed drive can achieve an efficiency classification of IES2. However, using other WEG lines of motors with the right drive, much better levels of efficiency can be reached.

WEG has a complete line of variable speed drives which exceed the IE2 requirements outlined in the IEC61800-9 standard. When combined with its robust and reliable motor line, the products create an integrated solution for all applications.

Client Focus

LOCAL PANEL MANUFACTURER STAYS AT THE LEADING EDGE

As a leading electrical control panel manufacturer, WEG Automation Africa stays at the cutting edge of innovation through its research and development driven approach which sees continuous product improvement setting benchmarks within the industry sector. The company was previously known as Shaw Controls and is part of the Zest WEG Group which is, in turn, owned by Brazil-based WEG Group.

According to Tyrone Willemse, business development manager – projects and contracts at WEG Automation Africa, the focus throughout the process is on safety and quality as well as local manufacturing capability. The company manufactures a range of low voltage (LV) and medium voltage (MV) electrical switchgear as well as LV fixed and withdrawable motor control centres (MCCs).

“Our fixed pattern boards have three configurations – front entry, back entry and back-to-back,” Willemse explains. “We can supply these in top or bottom busbar, or cable supply entry, to suit the customer’s glanding and entry preferences.”

WEG Automation Africa’s latest family of fixed pattern boards is internally arc classified at the highest level – Class C in accordance with IEC 61641 guideline.

Willemse says this makes it possible to conduct an assessment and repair of the board after a flash and then it can be returned to temporary use after a dielectric test, to minimise unscheduled downtime. He notes that the IEC61641 guideline is starting to be introduced into LV designs to enhance safety.

“The fully withdrawable MCC option offers the major advantage that operators do not work on a live board in front of the bucket,” he says. “This allows the technician to take the bucket out and move it to a safe environment before working on it.”

Significantly, WEG Automation Africa has introduced a new, fully-withdrawable MCC compliant with both IEC61439 and IEC61641 guidelines. While initially sourced from WEG’s manufacturing facilities in Brazil, the model is being considered for local build.

With the use of Solidworks modelling computer-aided design and engineering software, the MCC chassis is pre-punched to reduce wiring time. All digital components are loaded onto the system and carefully placed in the design of MCCs, so that equipment can be assembled and replicated to the highest standards.

“Our closed-loop project planning and control system also contributes to ensuring optimal efficiencies in the manufacturing line, saving both time and money for our customers,” he says.

The availability of Aluzinc instead of mild steel for the panel shells is an added advantage to the standard range of panels. This assists with the continuity of the earthing system and is corrosion-resistant, adding to its safety.

WEG Automation Africa’s extensive facilities at Robertsham in Gauteng also manufactures a variety of supplementary equipment for use on process and other plants. These range from custom-designed PLC panels, standalone starter panels, junction boxes, remote isolator panels and control desks. Panels are designed and produced for indoor and outdoor applications, whether skid-mounted, in a sub-station, in a container, or in a prefabricated room or specially constructed E-house.

Client Focus

EMERALD PROJECT BENEFITS FROM VERSATILE DIAMOND SORTING TECHNOLOGY

Adapting one of its X-ray fluorescence (XRF) diamond sorting range of machines, De Beers Group Technology has created a secure and efficient sorting solution for emeralds.

According to De Beers Group Technology head Gordon Taylor, the company’s sorting technologies have been applied to a range of minerals apart from diamonds, and these include gemstones like rubies to lower value commodities like manganese and coal.

“We are always on the look-out for new applications for our sorting equipment, which also employ X-ray luminescence, X-ray transmission, laser, magnetics and ultra-violet technologies,” says Taylor. “So we were excited by the opportunity to collaborate with Magnum Mining and Exploration on their Gravelotte emerald project in Limpopo province.”

In its trial mining and processing phase, Gravelotte has been gathering data to confirm the historic grades previously recovered at the Gravelotte project. In operation for much of the 20th century, total recorded production from this area was estimated at nearly 113 million carats. It was reportedly the world’s largest emerald mine of its type in the 1960s, employing over 400 sorters.

General manager of operations at Gravelotte, Wessel Marais, highlighted that the traditional manual method of sorting carried an associated security risk and also led to recoveries that were not optimum.

“Various mechanical sorting options are available on the market today,” says Marais, “and Magnum approached De Beers Group Technology to determine whether their diamond sorting technology could be adapted to emerald sorting.”

He says that testing of samples provided by Magnum was highly successful.

“This led to Magnum leasing an XRF machine from De Beers Group Technology for the duration of our trial mining, and the results to date have been very encouraging,” he says. “With the machines now deployed in the operational environment, research and development work is continuing in conjunction with De Beers Group Technology to refine the process.”

Taylor notes that constructive collaboration with customers is often an important element in extending the application of De Beers Group Technology’s equipment.

“On this project, we were able to conduct some fundamental investigation on the properties of emeralds to guide us in developing the most effective solution,” he says.

Nico van Zyl, De Beers Group Technology marketing and new business development manager, agrees. “You really need a partner who is willing to cooperate with you, as there is considerable effort that each has to contribute,” says van Zyl. “Our team is always enthusiastic about exploring new applications, and has the expertise and experience to know what is possible and how to achieve it.”

The De Beers Group Technology emerald sorting machine can make a potentially significant contribution to the success of the Gravelotte operation, with its high recoveries combined with excellent processing security. The project aims to reach a target of around 3 million carats a year as its initial production rate.

Before the run-of-mine material reaches the De Beers Group Technology XRF machine, it is crushed to -30 mm and put through a trommel screen for cleaning and further size reduction. After material containing emeralds is ejected from the material stream by the sorter, it is further sorted by hand and graded.

“De Beers Group Technology is constantly pushing the boundaries where our equipment can be applied, and has had significant successes in non-diamond commodities. Whether removing the value product or the waste from the process stream, our sorting technologies can be the game-changer in the viability of many projects,” Taylor concludes.

Client Focus

DRY-TYPE TRANSFORMERS MOVE INTO THE MAINSTREAM

The uptake of dry-type transformers in South Africa is now well beyond ‘niche’ applications, with local specialist Trafo Power Solutions installing a range of sizes across various sectors.

“In recent months, we have been involved in projects with small 50 kVA low voltage lighting transformers, right up to 4,5 MVA medium voltage customised units,” says David Claassen, managing director of Trafo Power Solutions. “These have been installed in healthcare facilities, commercial buildings, educational institutions, mines and data centres, as well as at solar energy plants.”

Among its recent contracts, the company has supplied a number of lighting transformers. It has also provided outdoor instrument transformers to facilitate measurement of voltage on overhead lines. These cast-resin voltage transformers (VTs) typically have 33 kV, 22 kV and 11 kV primaries with 110 V secondaries with between 50 VA and 500 VA burden.

“These are substantially lighter than their oil-cooled equivalents, and are, of course, safer due to the absence of oil in their design,” he says.

In the mining sector, a recent contract was the installation of 200 kVA dry-type transformers. This is often a corrosive environment in terms of water and dust, so a high ingress protection (IP) rating was applied. Claassen adds that a range of materials and paint can also be specified by the customer to further withstand corrosion.

Data centres are a fast growing aspect of the country’s digital economy, and Trafo Power Solutions is supporting this segment with its cast-resin transformers. It recently delivered and cold-commissioned two 2 MVA units for a data centre in Cape Town.

“These facilities obviously require the highest levels of reliability and protection from their electrical and electronic networks,” he says. “The windings and core of our units were designed for a K factor of 13, given the high non-linear load. An electrostatic shield was also installed, along with surge protection of the highest order.”

He notes that there was substantial time pressure on completing the contract, but flexibility and responsiveness that Trafo Power Solutions offers ensured on-time delivery.

At three small-scale solar plants, Trafo Power Solutions is providing three 800 kVA transformers which will step up power from 400 V to 22 kV. These applications involve a solar inverter for the 100% non-linear load, as well as an electrostatic shield between the primary and secondary windings.

Claassen emphasises that the business prides itself on the level of application engineering for each customer’s specific requirements.

“We understand what we are supplying and the risks faced by the customer and we design the solution accordingly,” he says. “Industry is certainly showing their faith that dry-type transformers can be applied in a growing range of applications.”

Client Focus

DOORS OPEN FOR STUDENTS AS CONCOR BUILDINGS PROGRESSES UPMARKET DIGS

Students have moved into the stylish rooms at The Campus student accommodation in Auckland Park, Johannesburg, as Concor Buildings fast tracks the project. The project has been developed by Century Property Development.

The 850-bed development, conveniently located close to both the University of Johannesburg and Wits University, is a welcome addition to the country’s limited stock of high quality housing for the growing student population. It comprises four main blocks – or towers – with the two south towers at six floors high and the two north towers with four floors. The two basement levels make space for 166 vehicles.

The high-end project includes a roof-top recreation area with swimming pool and built-in braais, study rooms, Wi-Fi throughout and a 25-seater cinema room. Starting on site in December 2017, Concor Buildings took the project to full fit-out of rooms with furniture including beds, fridges, TVs and curtain rails. The project was completed in the third quarter of 2019.

According to Concor Buildings’ site agent Justin de Villiers, challenges on the site included tight space constraints. Built between the Campus Square retail centre and Streatley Avenue, there was little laydown space for building materials and components, which included more than 7,500 m3 of readymix concrete and about three million bricks, as well as numerous precast items.

“An important innovation applied in the interests of saving time was the use of precast slabs and staircases, with structural load bearing brickwork,” de Villiers says. “The logistics of receiving, lifting and placing the precast elements – especially in the limited space – required careful planning and close supervision.”

Adopting the load bearing brickwork approach allowed Concor Buildings to start more quickly with the finishing trades as it eliminated the wait for the in-situ concrete frame to cure and for propping to be stripped off. The project utilised precast slabs over an area of some 20,000 m2, on all levels above the in-situ transfer slabs in the basement.

Building with structural brickwork does require special bricklaying skills, he highlights, and this is not a skill set in plentiful supply in South Africa. An important part of the value that Concor Buildings brought to this project is its experience in a range of building methodologies, and its network of reliable sub-contractors.

“Ensuring the right quality of bricklaying expertise, especially for a project like this, means knowing your supplier base well and monitoring their performance closely, even providing training to fine-tune skills where this is necessary,” de Villiers says.

The technique also required Class 1 mortar with a 15 MPa strength – compared to the normal strength of just 7 MPa – to provide sufficient compressive strength for the wall structures. A specialised mix was designed for the purpose and was regularly delivered by a service provider. This addressed the lack of space on site to mix mortar, and also allowed more effective quality control.

“The mortar and readymix supplier was able to conduct the necessary quality control tests at their facilities, while we also sent samples for independent testing,” he says.

The limited space also meant close supervision of the more than 40 sub-contractors, who often needed to occupy the same spaces simultaneously. At times there were as many as 800 workers on site, in addition to Concor Buildings’ 24-strong management team.

This made safety a key factor, says Margaret Dube, safety manager at Concor Buildings, especially with two tower cranes lifting and placing materials and the narrow access roadway requiring flagmen on constant duty. Working in a suburban area also meant special efforts to reduce noise, while observing restricted working hours.

Client Focus

CONTINUOUS POURS BY AFRISAM FOR GOTHIC AT WATERFALL MALL

The continuous casting of 764 m3 of concrete in just over 13 hours marked a milestone for Gothic Construction. This record continuous pour was successfully executed in conjunction with AfriSam during the casting of the first phase of the post-tensioned deck slab at the Waterfall Mall in Rustenburg.

The contract for the extension of the Waterfall Mall consists of the addition of an upper parking deck, the increase of retail space with full services for Dis-Chem to a total of 1 800 m2, as well as the extension of the basement parking area by 10 000 m2.

Gothic Construction elected to cast the large post-tensioned slab in two phases of continuous pours to eliminate the need for construction joints. The first phase covered an area of 2 646 m2 using a 30 MPa AfriSam Post Tension Mix with an integral water proofer supplied by Penetron.

Fifteen AfriSam readymix trucks ensured the uninterrupted supply of concrete with two 36-metre boom pumps on site place the concrete.

The second phase of the deck, covering 2 062 m2, was cast a few weeks later, using 624 m3 of concrete in another continuous pour and took 11 hours to complete.

Maurice Janse van Rensburg, AfriSam’s Territory Sales Manager for the North West Province, explains that this achievement was significant as all the concrete was supplied from AfriSam’s plant in Rustenburg only. The AfriSam team ensured uninterrupted delivery by using all available trucks, having a generator on standby and additional water tanks. Careful planning went into maintaining stock levels of all materials.

The roof of the basement parking extension also formed the slab for the increase in retail space. The most economic design was a coffer slab covering an area of 1 260 m2. The concrete supplied for the coffer slab was a special 30 MPa AfriSam Retainer Mix requiring minimal vibration. The mix was ideally suited for quality off-shutter finishes.

Representatives of both AfriSam and Penetron were on site during the concrete placing to take the necessary samples for quality testing. Gothic Construction also ensured that independent sampling was carried out.

Hannes van Rensburg, Gothic Construction’s Contract Manager, emphasises that the achievements on this project can be accredited to the good working relationship between all the stakeholders. The project is on schedule for completion in mid-December.