Use of Cement Hydration Heat as Heating Resource in Curing of Precast Concrete - Temperature Rise Simulation

Abstract

In the present paper, the effects of the thermal insulation layer on the temperature field of concrete board and further on the development of mechanical properties of the concrete are investigated by a temperature field model that takes cement hydration heat into account. In the modeling, factors that may influence the development of temperature in the board, including the thickness of the insulating polystyrene foam board, concrete strength, and casting seasons are considered. The effect of temperature rise on the mechanical properties of the concrete is evaluated through a model of degrees of cement hydration and compressive strength of concrete. The results show that the temperature inside the concrete board is greatly increased after placing a thermal insulation layer on the surface of the concrete after casting. More uniform temperature distribution along the slab thickness is observed compared to that without the thermal insulation layer. Temperature rise inside concrete board can greatly speed up cement hydration and the development of concrete strength. Curing with a reasonable thermal insulation layer allows the heat of cement hydration to be used effectively to increase the strength of concrete and to realize demoulding around 24 hours after casting.