Shrinkage characteristics of heat-treated ultra-high performance concrete and its mitigation using superabsorbent polymer based internal curing method

The shrinkage and cracking risk of heat-treated ultra-high performance concrete (UHPC) can be mitigated by using the superabsorbent polymer (SAP)-based internal curing method. The heat treatment (HT) accelerates the hydration reaction and resulting self-desiccation of UHPC; consequently, the UHPC experiences severe shrinkage during the HT. This study experimentally demonstrates that the shrinkage is effectively resolved by adopting the SAP-based internal curing method during the HT period as well as early-ages. This method also reduces the strain rate resulting from dimensional change, without showing an increase in drying shrinkage. The accurately conducted experiments herein can help to better understand the shrinkage characteristics of heat-treated UHPC and broaden the application of various internal curing agents.