Factors affecting the effectiveness of internal curing: A review

Abstract This paper mainly gives an overview of factors affecting the effectiveness of internal curing in cement-based materials from three aspects: the amount of internal curing water, characteristics of internal curing materials, and migration distance of internal curing water. It was found that (i) the equation developed to calculate the requirement of internal curing water for concretes with different water to cement ratios (w/c) based on Power’s model that includes silica fume and to get a maximum degree of hydration by prewetted lightweight (LWA) could not completely reduce autogenous shrinkage, (ii) the water release characteristics of internal curing materials (e.g., the time to release and the distance to migrate) under uniformly distributed conditions may override the influence of the spacing factor, and (iii) unexpected effects resulting from internal curing on the properties of concrete may occur if the characteristics of internal curing materials do not match the pore structure of concrete mixture.