USE OF SUPER ABSORBENT POLYMERS (SAPs) IN SELF COMPACTING MORTAR SYSTEMS (SCMs)

Abstract

This study is a continuation of earlier study made on SCP system [25].The project relates to a new concept regarding the prevention of self-desiccation in self-compacting mortar. The concept is based on the use of superabsorbent polymer (SAP) as an admixture in mortars. Through the use of such polymer, water-filled macropore inclusions are introduced inside the mortar, a technique known as water entrainment. Consequently, self-desiccation is mitigated due to the progressive discharge of water by SAP particles at the appropriate time during the hydration process. Nine formulations involving three different basic w/c ratios (0.38, 0.40, and 0.42) were studied at varying amounts of SAP (0%, 0.3% and 0.4%). The project rendered very promising results with some formulations showing restricted shrinkage and some showing even expansion. Overall, the shrinkage observed in mortar system was less as compared to paste system due to the dilution of cement when aggregate is introduced in it.