Effect of binary admixture of sepiolite and fly ash on carbonation and chloride resistance of modified cement mortar

摘要

This study presents the influence of binary admixture of sepiolite and fly ash on the performance of modified cement mortar including hydration heat, mechanical strength, carbonation resistance, chloride diffusion and the interaction between various binders. The experimental results showed that single incorporation of sepiolite can to some extent increase the strength of mortar, while it was even significant if a binary sepiolite-fly ash composite system was adopted. When the sepiolite content was 15%, the carbonation resistance of the modified mortar can be improved and its carbonation depth was decreased by 37.8%. It took place for chloride resistance of the corresponding modified mortar as well. Meanwhile, using binary admixture of sepiolite and fly ash, it can effectively shorten the induction period of cement hydration and reduce the cumulative hydration heat release of the modified system. (C) 2021 Published by Elsevier Ltd.