WHO'S WHO IN CONCRETE
Concrete pipes for sewerage and water systems Reinforced concrete pipes with highdensity polyethylene (HDPE) lining
Rocla supplies and manufactures a range of sewerage and water systems to municipalities and civil contractors throughout South Africa.
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mong Rocla’s flagship products are reinforced concrete pipes with highdensity polyethylene (HDPE) lining, which offer sewerage projects the same advantages as a conventional concrete pipe or a plastic pipe, in that it maintains its shape under load and is resistant to acid attack. Exposed concrete in the joints of a pipeline needs to be protected against corrosive gases, and Rocla has designed an HDPE capping strip, which is welded over the joint of the pipe after installation. It is generally 200 mm wide and the same thickness as the lining used in the pipe. This unique HDPE-lined pipe was recently commissioned for the Polokwane Wastewater Project, and 19 km of HDPE piping was supplied. Rocla also manufactures reinforced concrete pipes with sacrificial layers. The host pipe may be manufactured from dolomitic aggregate and ordinary Portland cement or siliceous aggregate and ordinary Portland cement. The sacrificial layer may be from
Rocla was also selected to manufacture and supply all the stormwater (spigot and socket) and interlocking pipes for Waterkloof Quarry – an old, 58 ha landmark situated on the Long-term corrosion protection border of Waterkloof Ridge and Monument The 300 mm to 600 mm reinforced concrete Park near Pretoria – which was developed into pipes are manufactured with the Xypex Bio-San a retirement estate. Rocla’s manufacturing C500 admixture. This is a uniquely designed capability helped in meeting the tight deadline admixture for the integral, long-term associated with the quarry development. protection of concrete in harsh For the recent Diepkloof sewer sewerage conditions, which upgrades, 2 715 piping have high levels of H2S that products and associated cause microbial-induced supplies – comprising corrosion in pipelines. RJ pipes, rubber rings, The protection is for manholes, cover slabs the full wall of the pipe and concrete lids – were and eliminates extra sourced from Rocla joint sealing. due to the quality of its HDPE-lined Without the Xypex Bio-San manufacturing processes manhole sections C500 admixture, the exposed and final product. concrete in joints of a pipeline Accessories for sewerage and needs to be protected against corrosive water projects also include pipes with gases and Rocla recommends joint sealing access holes, bends (Rocla can supply processes to avoid sewer corrosion activity. custom-made bends of up to 30 degrees), spigot and socket pipe systems, manhole Stormwater chambers with HDPE lining, and reducer and Projects such as the Nellmapius Ext 22 cover slabs. low-cost housing contract near Mamelodi The Rocla design, engineering and technical commissioned nearly 3 000 precast steelteam is available for pre-site design, and mesh-reinforced concrete stormwater pipes of on-site application advice when required. various nominal diameters from Rocla, for the This way, Rocla ensures that the appropriate 6 km stormwater pipeline being constructed. solution is selected and installed correctly. dolomitic aggregate and ordinary Portland cement or dolomitic aggregate and calcium aluminate cement.
IMIESA May 2021
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