Construction and engineering company Murray & Roberts exceeded State-owned freight logistics company Transnet’s recycled material target for the revamp of the City Deep container terminal, in Johannesburg, having processed more than 35 000 m2 of the terminal’s old concrete and almost 65 000 m2 of its layer works.
The City Deep revamp, which required the 144 000 m2 facility to be resurfaced and expanded by an additional 2 000 m2, was completed at the end of last year, with a key stipulation in the contract to recycle and reuse more than 10 000 m2 of the original surface concrete in the new build to meet Transnet’s sustainability objectives.
“We are proud to say that, with the client’s buy-in, we exceeded this requirement. The true innovation, however, was using a revolutionary new geopolymer concrete and high-volume pulverised flue ash concrete (HVPFAC) to surface the terminal, thereby raising the sustainability bar to even higher levels,” says Murray & Roberts infrastructure and building operating platform executive Jerome Govender.
HVPFAC relies on a relatively new technique that combines flue ash recovered from coal burnt in power generation plants with mineral slag to produce a concrete that has environmental benefits.
“HVPFAC has in the past been considered inferior to conventional concrete, but our processes and technological advancements have shown that this is no longer the case. “The compound significantly reduced water consumption, improved workability, minimised cracking and enhanced durability, demonstrating that new technologies can compete favourably with materials that had become industry staples,” explains Govender.
Meanwhile, geopolymer concrete relies on using industrial by-products to form a solid binder that has similar characteristics to Portland cement. This technique results in an up to 90% reduction in carbon dioxide emissions, while the concrete also has improved resistance to fire and aggressive chemicals.
“We firmly believe that the application of these technologies point to the future of construction methodologies. These are particularly relevant to South Africa given the focus on carbon emissions and the introduction of a carbon tax. Of course, it also takes foresight from our clients to adopt these technologies, and Transnet needs to be commended for allowing us the leeway to show how they could benefit,” Govender concludes.
This unique approach to sustainable building technologies used in the terminal’s upgrade was given credence early last year when the City Deep container terminal project was named runner-up in the Nedbank Capital Sustainable Business Awards’ Infrastructure and Renewable Energy category.
The category winner was property developer Growthpoint Properties’ Tshedimosetso House, in Pretoria, which was also developed by Murray & Roberts.
The company is based in Johannesburg, South Africa, where it has a public listing on the JSE. The company has principal offices in Australia, Botswana, Canada, Chile, Ghana, Mozambique, Namibia, Zambia, the United Arab Emirates and the US.