Effect of superabsorbent polymers on the drying and autogenous shrinkage properties of self-leveling mortar

Abstract

This paper aims at putting forward the shrinkage control measures for evaluating the effect and mechanism of shrinkage compensation of self-leveling mortar by analyzing the shrinkage characteristics of cementitious self-leveling mortar (SLM). The drying shrinkage, autogenous shrinkage and mechanical properties of the self-leveling mortar are analyzed by comparing it with the ordinary mortar. The difference between the two kinds of matrix was explained by the result of hydration and pore structure. The internal curing of self-leveling mortar was carried out by superabsorbent polymer. The variation of drying shrinkage and autogenous shrinkage of self-leveling mortar were tested with the content at 0%wt, 0.2%wt, 0.4%wt and 0.6%wt. The pore structure and pore size distribution were also investigated. The experimental results show that the self-leveling mortar has larger the drying shrinkage and smaller the autogenous shrinkage than those of ordinary mortar. The main reasons for this are the hydration delay and the change of pore structure of self-leveling mortar caused by the addition of organic admixture. The internal curing by using superabsorbent polymer has excellent effect on drying shrinkage and autogenous shrinkage compensation which decrease by 10% and 10.2%, respectively, when the content is 0.4%wt.