Effect of Superabsorbent Polymers on Workability and Hydration Process in Fly Ash Cementitious Composites

Abstract

The effects of three superabsorbent polymers (SAPs) on variations in the cement hydration process were studied by calorimetric measurements and the X-ray scanning technique. It was concluded that the influence of superabsorbent polymers on workability and autogenous shrinkage strongly depends on SAP water absorption/desorption kinetics. Gradual release of additional water stored by a SAP facilitated the formation of a denser and more homogenous cementitious matrix. The addition of fly ash to portland cement had a notable influence on the hydration process and microstructure development in mortars regardless of modifications by the SAP. Characteristic patterns attributed to pozzolanic reactions appeared to be related to the mortar densification measured by the X-ray absorption and quasi-adiabatic calorimetry techniques during the first 48 h.