Utilization of miscanthus combustion ash as internal curing agent in cement-based materials

Abstract

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 µm to 6.67 µm lowers the self-desiccation mitigation efficiency of biomass ash MA in the blended cement pastes.