Quarry Southern Africa May 2019 | Page 33

BENEFICIATION “The biggest benefit of precast slabs is that whatever can go wrong goes wrong in the factory rather than on site, and there what is likely to go wrong is typically with concrete compaction.” www.quarryonline.co.za  A bridge beam manufacturing line. CoreSlab manufactures a comprehensive range of high-quality T, Y, I, M, and F-type bridge beams, in addition to barriers and parapets. both processes, to make a better finish to the product and to save on certain expenses like additional labour incurred with conventional concrete, as well as fewer rejects — though it is quite a bit more expensive,” adds De Bruin. He says the company is still doing the input cost analysis on SCC as to whether the higher cost is offset by the lower labour cost on site. The factory itself is already highly labour intensive, albeit more productive and efficient. There are standard moulds for certain products, as stadia and reservoirs for instance typically have the same specced products, and the moulds can consequently be repeatedly reused. “Most of the products we manufacture are standardised — you can’t change the size of a rugby field in a stadium. We target the structural concrete market rather than architectural concrete. Though we have done some of the latter — like pavement seating and balustrades — it tends not to be economical as the learning curve is long, and the reject rate high through trial and error and is not really our core focus. “We know how to do suspended-concrete QUARRY SA | MAY/JUNE 2019_31