Effect of Bottom Ash and Mineral Admixtures on the Curing Sensitivity of Concrete

Abstract

In this paper curing sensitivity of concrete with bottom ash and multiple binders was studied. Bottom ash was used as an internal curing agent and a partial substitution of fine aggregate. Curing sensitivity index was calculated by considering compressive strength as an indicator. Two series of concrete with water to binder ratios by weight (w/b) of 0.35 and 0.55 were produced for compressive strength. The specimens were subjected to two curing conditions which are continuously water-cured and continuously air-cured. The curing sensitivity of concrete with multiple binders such as fly ash and limestone powder with bottom ash was investigated. It was found that for the mixes without bottom ash, the use of fly ash increased curing sensitivity while LP reduced curing sensitivity of concrete. It was also found that the use of bottom ash in concrete reduced the curing sensitivity especially at low w/b ratio. The concrete with limestone powder together with bottom ash were the least sensitive to curing. From autogenous shrinkage results, it was found that bottom ash reduced autogenous shrinkage of mortar significantly. From test results of compressive strength, curing sensitivity and autogenous shrinkage, bottom ash was proved to be one of the effective internal curing agents.