With the pandemic influencing rampant cost-cutting in the building industry, there is a growing danger of neglecting sound site practice which determines concrete performance and infrastructural safety and durability, cautions John Roxburgh, senior lecturer at The Concrete Institute’s School of Concrete Technology.
Construction site at sunset. Image credit: TCI
Roxburgh says the current economic crunch undoubtedly calls for saving costs – but not by sacrificing site expertise. Only contractors with a full grasp of concrete technology will be able to achieve a satisfactory balance between pricing and maintaining their company’s credibility, he feels.
“With good quality concrete – either batched on site or delivered there – the contractor has limited time for placing, compaction, finishing and curing. So, knowing what to expect is vital. Firstly, a good concrete practitioner should be able to assess the quality of the concrete supplied and decide whether it meets specifications or should be rejected. Then the concreting team needs to have timeously established how the concrete will be transported on site. They must also have organised and implemented placement and compaction methods, and ensured that the curing system has been fine-tuned with all necessary equipment and staff standing by,” Roxburgh adds.
He says there is a limited time to get concrete placed and compacted so the work needs to proceed straight away to ensure cracking potential is mitigated and that there is sufficient time to finish the concrete works.
“Sound concrete site practice can only be achieved by ‘concrete wisdom’. A trained concrete team will know how to prevent segregation in the concrete both through mix design and handling. The same applies to preventing crack formation and for suitable finishing and curing of the concrete. Property-owners whose structures fail within a short period of time are not likely to entrust more work to the under-performing contractors. The cost implications are simply too important for the developers and, for the contractors concerned, such failures could mean the end of their business,” Roxburgh warns.
He says the School of Concrete Technology’s ‘SCT20 – Concrete Practice’ course is a vital training tool to ensure the best site practice for concrete works. It provides trainees with essential concrete technology concepts and theoretical background to implement trustworthy and proven methods of dealing with concrete on site.
Because of Covid-19 restrictions, the SCT20 training is this year offered online as a self-study course at a considerable discount. The SCT lecturers are also available on Zoom or similar platforms to help with any difficulties students may encounter.
For more information and dates of the training, contact the School of Concrete Technology at 011 315 0300, or email info@theconcreteinstitute.org.za or visit www.theconcreteinstitute.org.za
