Influence of water to cement ratio on the efficiency of internal curing of high-performance concrete

Internal curing technology has been developed as a method for the reduction of autogenous shrinkage and cracking potential in high-performance concretes. The combination of autogenous and drying shrinkage, i.e. total shrinkage, of internally cured concrete is reported in the literature, almost unchanged after exposure to drying in a long term. On the other hand, the studied range of water to cement ratios is quite narrow. Accordingly, great interest aroused in the research of the effect of water to cement ratio on total shrinkage, as well as cracking potential of internally cured concrete. In this research, the restrained drying shrinkage of concrete with water to cement ratio of 0.33, 0.25 and 0.21, internally cured by means of water-saturated lightweight aggregate was studied. Strength, free drying shrinkage and mass loss of these concretes were also tested. The experimental results demonstrate that water to cement ratio has a considerable impact on cracking potential of internally cured concrete.