Effect of presoaked superabsorbent polymer on strength and permeability of cement mortar

Abstract

Curing of cementitious composites is critical to development of strength and impermeability. However, sufficient and complete curing cannot be achieved in many practical construction cases due to the complexity of construction and limited accessibility. Supplying moisture internally through presoaked superabsorbent polymer (SAP) is a viable option to minimise manual curing. This study investigates the effect of internal curing by presoaked SAP on the strength and permeability of cement mortar, subject to wet curing and air curing over 7 d, 28 d and 56 d respectively. Experimental results show that presoaked SAP with up to 30 g of contained water per gram of dry SAP (g/g) is effective as an internal curing agent in mortar under wet curing and dry air curing conditions. Deployment of presoaked SAP in mortar results in a significantly lower reduction in compressive strength compared to plain mortar, when no external water is available. Presoaked SAP has been found to minimise evaporative moisture loss from mortar while maintaining compressive strength and sorptivity at the desired level under both air curing and wet curing conditions. The findings from this study suggest that the use of SAP with pre-absorbed water has the potential to reduce the manual curing process, which also implies significant reduction in water consumption by the construction sector.