关键词: 内养护;水泥浆颗粒;自收缩;抗压强度

Abstract: Cement paste particles with different particle size and water-cement ratio were prepared as internal curing ( IC) material of concrete with low water-cement ratio.Three kinds of concrete was designed based on the optimum IC water to cement ratio, which sand is replaced by equal volume with the same size of cement paste particles with different water-cement ratio of 0.6, 0.7 and 0.8.Influence of cement paste particles with different water-cement ratio on the early-age autogenous shrinkage, compressive strength and microstructure of concrete was investigated.The results show that the water absorption rate of particles is positively correlated with the water-cement ratio and negatively correlated with particle size.Pre-wetted cement particles can significantly reduce the early-age autogenous shrinkage of concrete, and the autogenous shrinkage decreases with the increase of the water-cement ratio of particles.However, the mixing of pre-wetted particles will reduce the compressive strength of concrete, the compressive strength of concrete decreases with the increase of water-cement ratio of particles, the water-cement ratio of the IC particles should be optimized in the application.As the IC material of concrete, Cement paste particles can improve the pore structure of micro-interface, increase the compactness of the interface and reduce the autogenous shrinkage of concrete in the early-age.

Key words: internal curing;cement paste particle;autogenous shrinkage;compressive strength