A multi-disciplinary team of engineering and science students from the University of Johannesburg (UJ) outwitted 46 others to win the annual inland concrete boat race on Saturday, 1 October 2016. Team ‘Concrete Slaloms’ won first prize for the fastest stand up paddle ski (SUP) and first prize for best design and construction, with a waterproof GPS unit that tracked the position and speed of the craft in the student category. Concrete Slaloms used a cutting-edge concrete mix design to build their boat, which is also crucial in the long-term viability of infrastructure such as roads, bridges andbuildings.
The team comprised of Civil Engineering and Electrical Engineering students. This is the first year that one UJ team won both prizes at the event.
According to the competition rules, at least 30% of the mass of the SUP must be a mixture of blended cement and lightweight aggregates which constitutes at least 25% of the volume of the mix; no steel or metal are allowed to be used as reinforcement; and solid polystyrene or other foam to form the hull is not allowed.
In addition, each craft had to have ‘a demountable tracking device to capture the position, speed and direction of the SUP during the race’.
In short, not only did the competing teams have to make concrete float with the added weight of a strong human on top of it, and make it easy and fast to paddle, but each SUP also had to sport technology that generally doesn’t do well if it gets wet.
“We had four strong guys who could paddle. So we needed a boat that could carry 100kg plus and still have its deck above water. I went to Emmarentia Dam and spoke to Chris Couve, a professional Stand Up Paddler, about designing our SUP,” says Team Lead and Civil Engineering student Theo Smit.