Research Progress on Super Absorbent Polymer as Internal Curing Materials of Concrete

It is essential for the quality of concrete to carry out reasonable and adequate curing during the construction of concrete. The conventional external curing methods such as watering and coating, which are commonly used at present, have some problems of limited curing depth and dependence on the shape and construction part of the member. The internal curing method can solve these problems well and has a good application potential for the parts and structures that are easy to shrink, crack and inconvenient for external curing. This review represented recent development on the internal curing materials, and focused on the types of super absorbent polymer (SAP) as the promising internal curing materials and the mechanism of water absorption/release and the corresponding volume change. The water absorption/release behavior of SAP in cementitious materials and its influencing factors were summarized. The influence of SAP on the hydration process, pore structure and macroscopic properties of cementitious materials was discussed. In addition, the future direction of using SAP as an internal curing material for concrete was also envisaged.