Quarry Southern Africa May 2019 | Page 31

BENEFICIATION Precast concrete comes of age Bridge-beam moulds. The company manufactures all its forms and moulds to guarantee accurate casting. To mitigate downtime, the company also has its own workshop and maintenance team. CoreEngineering also has the skills and capacities to manufacture all the ‘cast-in’ components for CoreSlab’s comprehensive range of precast concrete products. Bridge-beam moulds. The company manufactures all its forms and moulds to guarantee accurate casting. To mitigate downtime, the company also has its own workshop and maintenance team. CoreEngineering also has the skills and capacities to manufacture all the ‘cast-in’ components for CoreSlab’s comprehensive range of precast concrete products. All photos by Eamonn Ryan Quarry Southern Africa’s Eamonn Ryan paid a visit to CoreSlab, a manufacturer of precast concrete systems, based on the outskirts of Polokwane, to see how the aggregate of a nearby quarry – Roodepoort Crushers – is beneficiated into precast concrete slabs. www.quarryonline.co.za  T he company was established in 2008 initially manufacturing just rib-and-block, but with a strategic plan to enter the hollow-core-slab market, which it did that same year. Both suspended concrete slab technologies are used in the commercial and industrial markets, with 70% to 80% of the company’s hollow-core slabs destined for the residential market, and approximately 20% for reservoirs’ roof structures. CoreSlab was among the leaders in South Africa in the manufacturing, supplying, and installing of precast hollow-core slabs — which a decade ago was a difficult sell. Today, it is far less of a hard sell, says Jaco de Bruin, MD of CoreSlab. Hollow-core slabs are used, in addition to multistorey buildings, in reservoirs, stadia, and bridges where they replace in situ concrete pouring. Although CoreSlab’s vast Polokwane manufacturing plant is sited next to its supplier quarry, that was not a factor in its choice of location. There are in fact, three quarries surrounding it, but the site was chosen primarily for its price and convenience. It still manufactures both product lines, which is essential due to the complementary strengths and weaknesses of each type, says De Bruin. “Some of the more established contractors don’t like hollow-core because they have the QUARRY SA | MAY/JUNE 2019_29