Internal curing - A suitable method for improving the performance of heat-cured concrete

Heat curing decreases the maximum achievable degree of hydration, long-term rate of increase of compressive strength, anti-permeability, and durability of concrete as it ages. In this study, we explored the suitability of internal curing for solving these problems and improving the performance of heat-cured concrete. Internal curing significantly improved the rate of increase in the later-stage strength, degree of hydration, and penetration resistance of heat-cured concrete; this was especially true when subsequent standard curing was also performed. It also resulted in a better interfacial transition zone with a more homogeneous distribution as well as a microstructure with a lower porosity around the internal curing material (lightweight fine aggregate) in the case of the heat-cured mortar. The characteristics of the internal curing material used to improve the performance of heat-cured concrete should be consistent with the heat-curing regime and match those of the cement paste.