On a visit to Mthatha in the Eastern Cape, Carmix SA had the opportunity to give back to the community
After supplying a loyal contractor with two Carmix units, he managed to supply concrete for the construction of four new reservoirs which would supply safe, clean drinking water to the very rural parts of Mthatha – but it didn’t stop there.
As these jobsites were in varying landscapes throughout the Eastern Cape, all four reservoirs, as well as bases of the cleaning and filtering tanks were cast by using the Carmix, which is incredibly versatile. With aggregates placed only 50m from the discharge site, what was planned to be a ten-day pour was completed in five days. The client was able to cast much quicker than anticipated. This was achieved by using two Carmix units of 3.5 cube capacity each, allowing one unit to cast bases for a reservoir, while the other poured thin blinding and a no-fines mixture at the next site.
Projects such as these require a variety of cementitious materials, namely; Blinding, no-fines mixes, 25-35mpa mixes and mixes containing admixtures (waterproofing agent). And in different proportions and quantities. By batching on site, the client could easily change from one mix to the other in the desired quantity due to the concrete mate computer system inside the Carmix. The concrete mate computer has the ability to have 30 different mix designs pre-programmed allowing you to switch between mixes by the touch of a button.
Access once the ring beam is cast becomes limited but due to careful planning and mapping of designated quadrants, the Carmix was able to discharge the desired mix inside the ring beam. The ring beam for this particular 1ML (mega litre) reservoir used a total of 58 cu/m of concrete. Being called a beam, the entire ring needs to be cast with one continuous pour. Because the concrete needs to be watertight, no cold joints are permitted. Cold joints could cause a crack or leak that gets bigger with time or causing the whole beam to break down and casting from scratch.
The reservoir has to hold 1,000 tonnes of water (1mnl/1 mega litre) and needs to be strong enough to withstand this force for many years to come. The concrete used for this project is a special watertight concrete and uses an admixture (CWA10) which serves as a waterproofing agent to prevent leakages and adds to the overall strength of the concrete and with the help of a Carmix this was achieved.