Influence of Super-absorbent Polymers (SAP) on Fresh and Early‐age Properties of High‐Performance Concrete

Abstract

Superabsorbent polymer (SAP) addition as internal curing (IC) agent in high-performance concrete (HPC) has been adjudged to be effective in mitigating autogenous shrinkage. The influence of SAP created voids fresh properties and early strength development of the HPC as cement hydrates is however yet to be well understood. This paper hereby presents a report of an experimental study on SAP incorporation as an internal curing agent in a low water/binder (W/B) HPC. Four reference HPC mixtures (M1F, M1S, M2 and M3) designed for a 28-day minimum cube compressive strength of 70 N/mm2 (MPa) were examined for the effect of SAP grain size, content and binder type on setting times and degree of hydration. The study also involved the determination of the pH-value of the simulated cement pore solution obtained from the binder combination types and its influence on SAP absorbency in concrete. It was observed that the addition of SAP resulted to increase in the setting times, while the degree of hydration of the HPC mixtures was found to increase as SAP content increases. The higher the SAP grain size, content, and W/B for all mixtures, the higher the chemically bound water ( ) at specific times and this increased as the hydration period increases.