The Effect of Using Fly Ash, Ground Sand and Water Supply Excess Sludge as Replacement Portland Cement Due to Compressive Strergth Drying Shrinkage and Autogenous Shrinkage of Concrete

Abstract

The using of replacement materials in Portland cement is used by-product from industrial to reduce environment problem. It can be improved quality and reduce cost of concrete. But shrinkage of concrete is main effect on durability. This research is study the effect of using fly ash, ground sand and water supply excess sludge with the same particle size as Portland cement was replaced by replacement materials at the rate of 10 and 20% by weight of binder. The compressive strength of 15 x 15 x 15 cm. concrete cubes were determined at the age of 7, 14, 28, and 60 days. The concrete specimen of 7.5 x 7.5 x 28.5 cm. is used for drying shrinkage and autogenus shrinkage with air, water and plastic sheet curing

The results showed that the compressive strength of fly ash concrete is lower than normal concrete at early age but it can be higher than normal concrete at the age of 60 days. The compressive strength of ground sand concrete and water supply excess sludge concrete are lower than normal concrete at all ages. At early age the compressive strength of water supply excess sludge concrete is higher than ground sand concrete. Drying shrinkage and autogenus shrinkage of fly ash concrete is less than ground sand concrete and water supply excess sludge concrete. At the rate of replacement 20% of fly ash concrete is lowest drying shrinkage and autogenus shrinkage. The curing under water is the lowest shrinkage.