For example, one option is to keep the landfill site open to these communities until materials become too difficult to recover. The informal waste pickers will slowly find other means of sustaining themselves and the landfill can, therefore, be closed without any further socio-economic impact. Another option is to help the affected communities establish small businesses, such as roadside markets and stalls, to sustain themselves as the Kiteezi landfill site is gradually closed. Project funding Timelines for the implementation of the IWM project are still uncertain. They are dependent upon the findings of the environmental and social impact assessments, as well as the ability of the GKMA to finance the project, including the proposed development of a methane gas-toenergy plant as a potential project. However, the country has been very successful in attracting private and grant funding for projects, to date. Through LANDFILL & WASTE MANAGEMENT municipalities, this is also used to fund feasibility studies. The country already has many bankable projects that are attracting further private investors and grant funding. This project is especially enticing considering the significant demand for IWM in the city, with many private participants having already identified an opportunity to become involved in providing essential services on behalf of the GKMA. The country also needs more renewable energy to help meet its carbon reduction targets and it has a developing electricity distribution grid to support these projects. These are further factors that potential funders may find appealing. “I remain very impressed with the country, especially its wealth of academic knowledge, which includes an intimate understanding of international trends and technologies. This continues to shine through in my interactions with relevant stakeholders. I believe Uganda is poised for great things,” Emery concludes. has a conducive climate and fertile soils that enable fruit and vegetable production for the greater part of the year. For example, bananas, mangoes, citrus, pineapples and tomatoes are grown on small subsistence plots and sold at the many streetside markets in the GKMA. There are hundreds of informal waste pickers who earn a livelihood collecting papers, containers and plastic at Kiteezi landfill for recycling purposes. The inorganic waste, consisting mainly of paper and plastic, is collected in very large bags that are rolled to collection trucks. This recovered material is then transported to various areas in the GKMA where it is reused. The waste diversion component of the project will potentially entail finding appropriate ways of using organic resources as opposed to landfilling it. There are a host of potential landfill diversion solutions that still need to be assessed by JG Afrika, RWA and Cardno, ranging from home composting through to larger, community-based or regional projects. As Emery notes, no two IWM projects are alike. They need to be adapted to the environment and the communities that they serve to be successful. Through this project, Uganda is also attempting to keep pace with the global trend of better managing residual materials. “The landfilling of these materials is harmful to the environment and causes serious health problems. Many countries are, thus, at the cusp of ensuring that all organic waste is diverted from landfills. In South Africa, for example, the Western Cape Provincial Government aims to completely eliminate organic waste from its landfills by 2027. This is a very ambitious target that could be emulated in other areas of the country via novel IWM projects,” he says. Socio-economic impact of landfill closure One of the main challenges of the project will be determining how best to manage the potential socio-economic impact that the gradual closure of the Kiteezi landfill site will have on the many informal pickers while organic waste is being diverted. There are numerous scenarios that need to be thoroughly assessed, and they will all require careful and extensive planning before being implemented. There are hundreds of informal waste pickers who earn a livelihood collecting papers, containers and plastic at Kiteezi landfill for recycling purposes An overview of a section of Kampala
ALL THE BELLS AND WHISTLES Warren Swart, product manager, Bell Equipment, represents the company’s custommade machines that are designed and manufactured by its dedicated Bell Application Equipment (BAE) division. This includes the Versatruck programme that comprises derivatives based on the chassis of the acclaimed Bell E-series articulated dump truck (ADT) range, such as water tankers. According to Swart, one of the primary purposes of a water tanker is dust suppression and the 50 000 ℓ tank was designed following interest from larger mining companies requiring more capacity on longer runways. “During dry seasons, dust suppression is a critical part of safety in mining and construction operations, from visibility improvements to pulmonary disease prevention. We are also able to offer firefighting options to provide an additional benefit, with one of our customers recommending our 38 000 ℓ water tank for mitigating fire risks in tall structures due to the remote water cannon stream reaching heights above 30 m,” Swart explains. The 50 000 ℓ tank is paired with the B60E powerhead, making it one of the largest articulated water tankers available on the global market. While it enables Bell to offer a full range of tank sizes, the B60E water tanker importantly offers commonality of parts to the growing number of customers running fleets of B60Es. 16 000 ℓ water tanker development At the opposite end of the scale, the 16 000 ℓ water tanker was developed Local OEM Bell Equipment has expanded its range of water tankers and now offers eight tank sizes following the introduction of 16 000 ℓ and 50 000 ℓ offerings. for new E-series water tankers specifically with Bell Equipment’s Australian customers in mind. “Meeting the unique requirement to have a smaller articulated water tanker in tight industrialised areas stands as a testimony to our long-standing skill of listening to our customers’ requirements and innovating solutions to meet these needs,” says Swart. “The 16 000 ℓ water tank complements the 38 000 ℓ water tank commonly sold into Australia with a top fill chute only, which excludes the standard dam or reservoir filling solution we have available. External plumbing is also kept to a minimum and guard rails are used to increase safety when an operator is required to climb on top of the water tank.” BAE enables Bell Equipment to give focus to the design and manufacturing of specialised products for individual markets and ensures that quality standards are on par with the rest of the Bell range. With regard to the water tanker design, Swart explains that the centre of gravity is kept low to reduce the risk of rollovers, while a fully engineered baffle system prevents water surge and slosh, providing increased stability for greater safety. In addition, tanks are coated internally with a dual epoxy paint lining as standard to prolong the life of the tank. “Most of the truck is built through Bell Equipment’s standard high-quality production facility, while the water tankers, as specialised vehicles, are manufactured on our BAE line. This ensures that we remain cost competitive, while providing the time that our specialised vehicles require to meet our world-class quality standards. We adhere to international welding quality standards for earthmoving and construction equipment (AWD D14.3), with the inclusion of additional Bell-specific quality inspection processes, such as a pressurised leak test on all tanks produced,” Swart adds. Water cannon and spray configurations “Our water tanks can be customised to meet the customer’s requirements with a wide range of options. To mention a few, we offer a manual water cannon with a long-range spray nozzle and a remote water cannon that is remotely controlled using a joystick inside 50 IMIESA August 2022 Warren Swart, product manager, Bell Equipment, with a 27 000 ℓ water tank ready for fitment
VEHICLES & EQUIPMENT the cab. This cannon has an adjustable fog/ stream pattern and a variety of flow settings between 1 100 and 3 200 litres per minute. Both water cannons feature high-quality components, making them highly suitable for heavy-duty applications,” explains Swart. Other options include additional battery spray valves that expand the spray pattern horizontally. Additionally, a range of rear spray bars are available, beginning with a gravity-fed dribble bar that delivers an even spread pattern covering the width of the vehicle. Penetration spray bars are also available, with either nozzles or holes, and are pressurised by the pump to create a jet of water that is not affected by wind. These options are complemented with the design of an in-cab control panel for all water tank functions. This provides an ergonomically sound control environment for the operator inside the cab. The in-cab control panel increases productivity and ensures operations are never interrupted by the need to exit the cab and manually open external valves. Perhaps the most important feature is that since Bell, as an OEM, builds both the main chassis and the additional component required by the customer – in this case, the water tank – the finished product enjoys full factory support. This means that wherever in the world a customer takes a Bell Versatruck solution, they can be guaranteed of Bell Equipment’s technical support offered through the company’s global network of customer service centres and dealers. Note: The B25E and B30E are also available with a diesel bowser option, with plans to expand this range to match the current water tank series. Bell powerhouse pairings for the company’s range of water tanks: 16 000 ℓ Bell 2304E / Bell 2806E 18 000 ℓ B18E 23 000 ℓ B25E 23 000 ℓ B30E 27 000 ℓ B40E 35 000 ℓ B45E 38 000 ℓ B50E 50 000 ℓ B60E Our water tanks are engineered to perfectly integrate with our E-series ADTs as a complete unit.” Tankers can be fitted with a manual water cannon with a long-range spray nozzle, or one that’s remotely controlled via a joystick inside the cab Bell Equipment’s 16 000 ℓ water tank
52 IMIESA August 2022 With the latest-generation HC series, Hamm is bringing together all compactors with an operating weight of 11 t to 25 t on a single platform. Research and development (R&D) upgrades include an up to 15% increase in centrifugal force, as well as improved efficiencies thanks to an integrated ECO mode, with options that include automatic engine stop. Going forward, Hamm’s small compactor segment (5 t to 7 t) will be represented by the HC CompactLine series. In addition to improved driving comfort, Hamm’s R&D team have increased the traction and gradeability. The groundbreaking HX series The HX series is the new flagship from Hamm for asphalt construction. These pivot-steered tandem rollers (7 t or 9 t) are following in the footsteps of the DV+ series and are designed for high-quality production. There are models with split and non-split vibration and oscillation drums, as well as combination rollers. A key component of the well-conceived compaction technology is the integrated automatic reverse function, which brakes and accelerates the rollers quickly, but smoothly. The electrically adjustable seat operating unit, which automatically turns to the direction of travel when reversing, is also a unique feature. Eight tandem rollers with electric drive Unveiled for the first time at bauma 2022 are Hamm’s eight electrified tandem rollers in the HD CompactLine series. Their operation and compaction parameters are identical to the corresponding diesel-driven machines, with the key difference that they are completely battery-powered. Significantly, these rollers can work for an entire workday on a single charge. These models also include the world’s first electric combination roller with oscillation. Tyre heating with diesel instead of gas Another innovation showcased at bauma is Hamm’s improved heating solution for its pneumatic tyre rollers, which does away with the need for gas. The new burner is fed with diesel from the fuel tank, efficiently preventing asphalt from adhering to the tyres during compaction. Smart Doc and Smart Compact To optimise overall results, Hamm has also invested in digital technologies, which include the Smart Doc app. The latter displays, in real time, how the compaction develops and links the machine data to GNSS position data. The app uses this data to create compaction reports in PDF format and is therefore also suitable for self-monitoring. An allied development is Hamm’s Smart Compact compaction assistant, which raises the quality of the compaction to a new level by integrating local weather data into the evaluation. In addition to the physical properties of the asphalt, the system also evaluates its complex cooling behaviour. Using this, it continuously determines the optimal setting for each drum separately – i.e. whether compaction is carried out with vibration, with big or small amplitude, with oscillation or statically. As an added benefit, Smart Compact can determine when to move the roller into ECO mode and therefore save fuel. COMPACTION INNOVATION on show at bauma VEHICLES & EQUIPMENT Hamm’s new Smart Doc and Smart Compact digital tools take compaction performance to a new level At bauma 2022, Hamm will showcase latest-generation series updates as well as new models that include electrically powered compact rollers
• Precast concrete plasticising admixtures • Ready-mixed concrete plasticising admixtures • Extended workability polymers • Set retarding admixtures • Hardening accelerators • Viscosity modifying admixtures • Form release agents • Synthetic fi bres • Pozzolan-activity mineral additions • Permeability-reducing admixtures • Water-repelling admixtures • Anti-washout admixtures • Expanding agents • Drying shrinkage-reducing admixtures • Clay mitigating admixtures • Pumping aides • Air entraining and foaming agents • Concrete rescue packs • Evaporation-retarding admixtures TECHNOLOGICAL INNOVATION IN THE CONCRETE INDUSTRY STARTS WITH MAP PRODUCTS. Learn more at mapei.co.za Tel: +27 11 552 8476 Email: [email protected] Competing against the best, Rocla and Technicrete were honoured with Engineering Excellence Awards in the Infrastructure and Paving categories at the Concrete Manufacturers Association (CMA) 2022 Digital Awards for Excellence. “The CMA’s recognition adds value to the entire Rocla and Technicrete teams’ efforts to deliver a superior solution,” says Malebusa Sebatane, group manager: Marketing and Communications for the ISG Group, which owns the Rocla and Technicrete brands. Rocla, winner of the Infrastructure category, supplied over 19 km of HDPE lined precast piping to Safcrete Construction for the Polokwane Wastewater Treatment Project. The latter was commissioned by Polokwane Municipality to upgrade an outdated sewerage system servicing the Seshego area. The precast concrete pipes supplied measured 1 980 mm x 1 000 mm and 2 116 mm x 900 mm. The placement of each pipe also required the insertion of a rubber ring and the welding of a ‘capping strip’ on the inside of each individual joint to ensure a proper seal. Amorflex Announced as the winner of the Paving category, Technicrete’s internationally licensed Armorflex Erosion Control System 140 was selected for upgrades to major stormwater systems in Mamelodi Ext 4 and 5 north-east of Pretoria. Tefla, who undertook the project, said Armorflex’s easy installation enabled the company to outsource 30% of the work to the local community, facilitating a skills transfer element in the project. Based on a trapezoidal channel analysis of water volumes and velocity, Armorflex 140 was selected as the best system to install for the gradual channel to be constructed. recognised at CMA Awards ROCLA AND TECHNICRETE A section of Rocla HDPE lined precast piping installed for the Polokwane Wastewater Treatment Project The Armorflex Erosion Control System 140 was selected for upgrades to major stormwater systems in Mamelodi Ext 4 and 5 north-east of Pretoria. CEMENT & CONCRETE
PROFESSIONAL AFFILIATES IMESA IMESA AFFILIATE MEMBERS
IMIESA August 2022 55 AECOM [email protected] AFI Consult [email protected] Alake Consulting Engineers [email protected] ARRB Systems [email protected] Asla Construction (Pty) Ltd [email protected] BMK Group [email protected] Bosch Projects (Pty) Ltd [email protected] BVI Consulting Engineers [email protected] CCG [email protected] / [email protected] Corrosion Institute of Southern Africa [email protected] Dlamindlovu Consulting Engineers & Project Managers [email protected] EFG Engineers [email protected] Elster Kent Metering [email protected] EMS Solutions [email protected] ERWAT [email protected] GIBB [email protected] GIGSA [email protected] GLS Consulting [email protected] Gorman Rupp [email protected] Gudunkomo Investments & Consulting [email protected] Hatch Africa (Pty) Ltd [email protected] HB Glass Filter Media [email protected] Herrenknecht [email protected] Huber Technology [email protected] Hydro-comp Enterprises [email protected] Infrachamps Consulting [email protected] INFRATEC [email protected] IQHINA Consulting Engineers & Project Managers [email protected] iX engineers (Pty) Ltd [email protected] JBFE Consulting (Pty) Ltd [email protected] JG Afrika [email protected] KABE Consulting Engineers [email protected] Kago Consulting Engineers [email protected] Kantey & Templer (K&T) Consulting Engineers [email protected] Kitso Botlhale Consulting Engineers [email protected] KSB Pumps and Valves (Pty) Ltd [email protected] KUREMA Engineering (Pty) Ltd [email protected] Lektratek Water [email protected] Makhaotse Narasimulu & Associates [email protected] Mariswe (Pty) Ltd [email protected] Martin & East [email protected] M & C Consulting Engineers (Pty) Ltd [email protected] Mhiduve [email protected] MPAMOT (PTY) LTD [email protected] Mvubu Consulting & Project Managers [email protected] Nyeleti Consulting [email protected] Odour Engineering Systems [email protected] Prociv Consulting & Projects Management [email protected] Rainbow Reservoirs [email protected] Re-Solve Consulting (Pty) Ltd [email protected] Ribicon Consulting Group (Pty) Ltd [email protected] Royal HaskoningDHV [email protected] SABITA [email protected] SAFRIPOL [email protected] SAGI [email protected] SALGA [email protected] SAPPMA [email protected] / [email protected] SARF [email protected] SBS Water Systems [email protected] Silulumanzi [email protected] SiVEST SA [email protected] Sizabantu Piping Systems (Pty) Ltd [email protected] Siza Water (RF) Pty Ltd [email protected] Sky High Consulting Engineers (Pty) Ltd [email protected] SKYV Consulting Engineers (Pty) Ltd [email protected] Smartlock [email protected] SMEC [email protected] Southern African Society for Trenchless Technology [email protected] SRK Consulting [email protected] Star Of Life Emergency Trading CC [email protected] TPA Consulting [email protected] V3 Consulting Engineers (Pty) Ltd [email protected] VIP Consulting Engineers [email protected] VNA [email protected] Water Institute of Southern Africa [email protected] Wam Technology CC [email protected] Wilo South Africa [email protected] WRCON [email protected] WRP [email protected] Zutari [email protected] To keep pace with population growth, a new wastewater treatment plant was recently constructed in the Northern Cape town of Orania, which now has four times the processing power of the old works. Orania Infrastruktuur was the appointed contractor on the project, which ran from March through to mid-December 2021. Sika SA was consulted, asked to consider solutions, and then supplied the relevant specified materials to the project. It was important to ensure that the concrete works and joints be totally watertight. The basic methodology initially required the installation and fastening of Sika-Waterbar DR EG, an expansion joint sealant for watertight concrete construction, prior to casting of the concrete. SikaPlast 220VX, a water-reducing multipurpose admixture was dosed at the readymix supplier, and Sika WT-200 P was then added to the load just prior to discharge, and thoroughly mixed. Sika WT-200 P is a combined water-resisting and crystalline waterproofing admixture used to reduce the permeability of concrete and to enhance the selfhealing abilities of the concrete. SikaPlast-220 VX can be used in both readymix and on-site batching applications, and is ideal for use with lean, harsh concrete mixes, and concrete containing slag, fly ash or microsilica. Additionally, SikaPlast-220 VX’s superplasticising action provides high-slump, flowing concrete that maintains excellent workability and may be placed with minimal vibration. Application criteria The selection of a suitable Sika-Waterbar is governed by the type of joint, the concrete thickness, grade of concrete, reinforcement position, expected movement (expansion/shear), as well as the water head to which it is to be exposed. The correct consistency of the concrete itself is also important, and the aggregates must be well graded. The Sika-Waterbar DR EG range is made from thermoplastic PVC and can therefore be easily heat welded – as adhesive jointing is not permitted. Further advantages include high tensile strength and elongation, permanent flexibility, resistance to hydrostatic pressure/ stress, and a resistance to natural soil and groundwater mediums – all important factors in ensuring a watertight structure. CEMENT & CONCRETE WATERTIGHT SOLUTIONS for new treatment works A section of the concrete forming part of the new wastewater treatment works
APE Pumps 15 AfriSam South Africa 40 ARRB Systems 32 Bell Equipment Group Services 28 CIDB ERWIC Awards 22 EnviroServ Waste Management IBC Gabion Baskets 11 Hydrogen-Africa 21 IMESA 4, 16 & 54 JPCE 46 Keller Nederland 2 Kenzam Equipment 30 Mapei South Africa 53 MDCC OBC Much Asphalt OFC Rocla 39 Sabita 29 SAPPMA 27 Sizabantu Piping Systems IFC SMEC South Africa 19 Strategic Business Services 24 VEGA Controls SA 8 INDEX TO ADVERTISERS 56 IMIESA August 2022 Foamed concrete can be produced on a small scale, even at site level, and is relatively easy to place and finish without heavy or expensive equipment. It has been used as a structural material in schools, apartments and housing developments in countries such as Brazil, Singapore, Kuwait, Nigeria, Botswana, Mexico, Indonesia, Libya, Saudi Arabia, Algeria, Iraq and Egypt,” Perrie states. Foamed concrete is a cementitious material, with a minimum of 20% (per volume) foam entrained into the plastic mortar but, as no coarse aggregate is used, the term ‘concrete’ is basically inappropriate, he explains. It is produced by entrapping numerous small bubbles of air in cement paste or mortar. Mechanical foaming Mechanical foaming can take place in two principal ways: • by pre-foaming a suitable foaming agent with water and then combining the foam with the paste or mortar • by adding a quantity of foaming agent to the slurry and whisking the mixture into a stable mass with the required density. Perrie says the most commonly used foam Bryan Perrie, CEO, Cement & Concrete South Africa CEMENT & CONCRETE concentrates are based on protein hydrolyzates or synthetic surfactants. These are formulated to produce air bubbles that are stable enough to resist the physical and chemical forces imposed during mixing, placing and hardening. Foamed concrete is self-compacting, freeflowing and pumpable, and therefore easy to place in inaccessible places. It has good thermal and acoustic properties and is frost resistant. It is, however, too weak for direct exposure to traffic and hail, and should be protected by a wearing layer. Dry density “It is standard practice to classify foamed concrete according to its dry density. The density is determined from oven-dried specimens, and the actual density of foamed concrete would usually be higher than this density, as there would generally be evaporable water present in foamed concrete. The presence of water in foamed concrete elements also results in an increase in thermal conductivity,” Perrie explains. Since the introduction of cellular concrete systems to the construction industry almost six decades ago, its use has almost exclusively been limited to non-structural void filling, thermal insulation, acoustic damping, trench filling for reinstatement of roads and for building blocks. In the Netherlands, foamed concrete has been used not only for level corrections in housing developments, but also as a fill material where ground subsidence has taken place and as a founding layer for road works on very weak soils. “Historically, foamed concrete has been perceived to be weak and non-durable with high shrinkage characteristics. Unstable foams have in the past resulted in foamed concrete not being suitable for reinforced, structural applications. However, the development of protein hydrolisation based foaming agents and specialised foam generating equipment has improved the stability of the foam, making it possible to manufacture foamed concrete for structural applications,” adds Perrie. “But it is important to ensure that the air entrained into the foamed concrete is contained in stable bubbles that remain intact and isolated to ensure that the permeability of the cement paste between the voids is not increased,” Perrie concludes. www.cemcon-sa.org.za Foamed concrete is the most popular of all low-density concretes in developing countries, mainly because of its low capital expenditure on equipment and the ready availability of its principal materials, says Bryan Perrie, CEO of Cement & Concrete South Africa (CCSA). Economical foamed concrete SUITABLE FOR LIMITED BUDGETS
With over 40 years’ experience in the waste management industry, collaboration with customers is how we drive the circular economy. We implement agile and innovative waste solutions, proudly ensuring environmental peace of mind through our commitment to industry standards. From waste to resource TODAY’S WASTE I S TOMORROW’S RESOURCE FIND OUT MORE 27588