Autogenous Shrinkage Reduction with Untreated Coal Bottom Ash for High-Strength Concrete

Abstract

The effect of untreated bottom ash on autogenous shrinkage reduction for high-strength concrete was investigated. A type of commercialized artificial lightweight aggregate was used as a reference material to compare the efficiency of internal curing by bottom ash. A type of commercialized artificial lightweight aggregate-expanded shale-was used as a reference material to evaluate the efficiency of internal curing with bottom ash. Prior to evaluating the shrinkage of concrete, absorption/desorption properties and water transfer characteristics of both materials were measured. The deformations of the concrete with both materials were measured under sealed and unsealed conditions. In addition, the mass loss of concrete by drying was measured. It was found that the autogenous shrinkage of concrete was decreased or eliminated by the use of bottom ash aggregates. However, the efficiency of the bottom ash with respect to shrinkage reduction was less than the expanded shale.