Construction World September 2024

AfriSam is also an important contributor to environmental sustainability.

durability standards and the related testing were adopted by key government agencies responsible for infrastructure – and from there were embraced by ever wider circles within the construction industry. “Durability is a particular concern for any concrete structures which are permanently exposed to the elements,” he highlights. “To make the most of the substantial investments they require, these structures need to withstand aggressive environments without needing any undue attention before the end of their design lives.” Applying these new durability standards, however, was initially no simple matter – requiring key players like AfriSam to participate actively in an industry-based Durability Committee to standardise the necessary testing equipment and methods. “Indeed, we took a leading role in the process by establishing a dedicated Durability Laboratory at our Centre of Product Excellence in Roodepoort,” he explains. “Apart from the universities, we were one of the first to install the correct test equipment – allowing us to assess various concrete mixes in terms of their compliance with durability specifications.” AfriSam was able to conduct these tests for contractors nationwide – even for projects in which the company was not directly involved. Importantly, this work coincided with progress AfriSam had already made in its understanding of supplementary cementitious materials. Until this time, it was widely accepted that the quality of a concrete was primarily a function of the volume of cement it contained. Alternative materials – like pulverised fly ash or granulated blast furnace

of large high investment projects on which the economy relied. He points out that it was no longer enough to satisfy only a structure’s strength requirements during and after construction. It was also vital to optimise longevity, and ensure maintenance costs were kept to a minimum. “Especially with public structures like bridges and roads, large investments were being made in the country’s future, and these investments needed to be protected, inter alia , through more durable construction materials,” he explains. “Apart from the cost of maintaining public assets like these, there are also severe disruptions caused when structures have to be repaired.” In the 1990s, therefore, durability in construction became a strong theme of international best practice, which South Africa embraced enthusiastically. AfriSam, he says, took a leading role in producing the materials that would allow projects to meet the exacting durability specifications being developed and applied. “We also took a keen interest in understanding how the relevant tests needed to be conducted, so concrete could comply with new durability standards,” he says. “This became very important in the 2000s, during the build-up to the hosting of the Soccer World Cup in 2010. During this time, many of these specifications were applied in the construction of stadiums, the Gautrain, airport upgrades and other mega-projects.” Dawneerangen pays tribute to two academics in particular – Professor Mark Alexander at the University of Cape Town and Professor Yunus Ballim at the University of the Witwatersrand – who pioneered South Africa’s Durability Index tests. The

15 CONSTRUCTION WORLD SEPTEMBER 2024