Effect of mechanically-induced fragmentation of polyacrylic superabsorbent polymer (SAP) hydrogel on the properties of cement composites

Maciej Kalinowski , Piotr Paweł Woyciechowski , Joanna Julia Sokołowska

Abstract

The effectiveness of internal curing of cement composites with the use of SAP depends, among others, on its chemical composition and its granulation. However, the interaction between hydrogel and other components of the concrete hasn’t been fully investigated. The aim of the presented research was to investigate the impact of cement/aggregate particles friction during mixing on the properties of water-saturated SAP. Novel mechanism of SAP hydrogel fragmentation was identified as one of the causes of differences in internal curing efficiency dependent on SAP state (water-saturated/non-saturated). Due to mixing process the surface area of tested SAP increased approx. 10 times. It was found that dosing SAP in a hydrogel form results in more homogenous SAP distribution within cement matrix. Such a modification of SAP dosing process enables to increase the efficiency of concrete internal curing. It was confirmed by obtained results for concrete mechanical strength and freeze-thaw resistance.