The effect of Superabsorbent Polymers (SAP) on microstructure and mechanical properties of fly ash cementitious mortars

The paper is focused on microstructure and strength development in fly ash cementitious mortars containing superabsorbent polymers. In order to evaluate the effect of different water absorption/desorption kinetics of SAPs, comprehensive MIP and SEM analysis supplemented by the mechanical properties assessments have been performed. The vast majority of pores created by SAP are ‘ink-bottle’ and/or closed. Gradual release of water stored by SAP facilitates formation of denser, more homogenous and predictable cementitious matrix, further enhanced by the pozzolanic reaction of fly ash with portlandite. Addition of SAP with high water absorption capacity results in an increased compressive strength.