Performance of internal curing materials in high-performance concrete: A review

High-performance concrete (HPC) has been increasingly used in modern engineering structures because of its superior material properties compared to ordinary concrete. One of the most critical issues in the application of HPC is serious early cracking, which is often encountered in the structures that involve mass concrete. Internal curing is an effective method to address the early cracking of HPC. Based on the reported data from the literature, it is found that the efficiency of the internal curing in HPC is highly dependent on the amount, the particle size, and the absorbed water of the internal curing material. This paper provides a comprehensive review of different internal curing materials for HPC, as well as their effects on the HPC mechanical properties, autogenous shrinkage, and durability. The predicting equations for HPC with different internal curing materials are also proposed, which would assist further research and application of these materials.