Effect of SAP on Properties of High Performance Concrete under Marine Wetting and Drying Cycles

The internal curing effect of superabsorbent polymer (SAP) on the properties of high performance concrete (HPC) under marine wetting and drying cycles (WD cycles) was investigated. Compressive strength, hydration and chloride migration were experimentally investigated and the results were evaluated by compasison with those under fresh water curing (FW). Water absorption and porosity were also evaluated only under WD cycles. The results showed the important influence of wetting and drying cycles on the properties of SAP modified HPC properties. Carefully designed, SAP minimized the long-term compressive strength of HPC under marine WD cycles. The hydration rate was faster in the initial curing, but became lower as compared with that cured in FW. In addition, SAP improved the long-term water absorption resistance and chloride migration resistance of HPC under marine WD cycles. The examination of the porosity showed a lower increase of the volume of capillary pores in SAP modified HPC under long term WD cycles compared with that without SAP. Therefore, internal curing by SAP could improve the durability properties of HPC under marine WD cycles.