Cement as we know, has large amount of calcium compounds in it. While in normal conditions this is not an issue, problems start surfacing when it comes to construction in corrosive soils, like in the Middle East. Middle Eastern soils are high in sulphate and chlorides, which attack the calcium in the cement. Construction in such areas is a big challenge. The Wagner family from Toowoomba have now perfected a calcium- free cement mix, which is inherently immune to corrosive deterioration.
After eight years of research for perfecting the concrete without Portland cement, the product is now ready for its commercial sale. The new mix was used at the airport which the Wagners built near Toowoomba, Brisbane West Wellcamp.
Trials on pre-cast tunnel segments of the Wagners’ earth friendly concrete (EFC), as they call it, have been completed in Malaysia and, last week, at Doha in Qatar. The concrete uses fly ash and slag, recycled from steel making and coal-fired power stations, is combined with chemical activators to create a geopolymer binder.
EFC does not need added protection from corrosion, and its flexural strength and low shrinkage makes it perfect for underground tunnels.