Investigation on physical properties, strength and phase evolution of binary cementitious materials made of CFBC ash and lime

Abstract

Circulating fluidized bed combustion ash (CFBC ash) is the wasteof coal-firedcirculating fluidized bed power plant boiler.CFBC ash contains amounts of free limeand anhydrite, which has a self-hardening andexpansion property. This paper studies the influence of CFBC ash fineness and lime or slaked lime dosage on the physical properties, strength and phase evolution of binary cementitious materials (lime or slaked lime-CFBC ash). The experimental results show that when lime or slaked lime dosage is below 30%, throughCFBC ash getting finer, setting timeof binary cementitious materials becomes shorter and compressive strength of that increases, butwater requirement of normal consistency of that decreases to some extent. And when CFBC ash fineness is constant, with the increment of lime dosage, setting timeof binary cementitious materials becomes shorter and water requirement of normal consistency of that increases, butcompressive strength of that declines first and then increases. But when CFBC ash fineness is constant, with the increment of slaked lime dosage, setting timeof binary cementitious materials becomes longer and compressive strength of that declines, butwater requirement of normal consistency of that increases.