Utilization of miscanthus combustion ash as internal curing agent in cement-based materials: Effect on autogenous shrinkage

The present study aims to evaluate the characterization of combustion ash of miscanthus and its possible application for self-desiccation and autogenous shrinkage mitigation in cement-based materials. Comprehensive tests were performed on the sealed samples to evaluate the behavior of self-desiccation and autogenous shrinkage of low water/binder ratio (0.25) cement pastes blended with miscanthus ash (MA). The lab-generated MA is featured by high content of amorphous silica and porous structure. Its porous structure with pore size distribution mainly within the range of 30-50 nm in diameter makes it a potential internal curing agent for self-desiccation and autogenous shrinkage mitigation. Incorporation of 20% by weight MA into cement paste shows high efficiency in self-desiccation mitigation, contributing to the significantly reduced autogenous shrinkage. Decreasing the mean particle size from 20.43 mu m to 6.67 mu m lowers the self-desiccation mitigation efficiency of biomass ash MA in the blended cement pastes. (C) 2019 Published by Elsevier Ltd.