Evaluation of heat of hydration, temperature evolution and thermal cracking risk in high-strength concrete at early ages

摘要

Adiabatic temperature rise (ATR), early-age strength development for a normal-strength concrete (NC) and a high-strength concrete (HSC) mixes widely used in bridge construction were experimentally determined. The hydration parameters and the heat of hydration of the two concrete mixes were compared. The temperature and developments and early-age cracking risk in a bridge pier using NC and HSC were then evaluated. The results show that when replacing NC with HSC, the pier cross section could be reduced by 35%, however, the temperature difference was slightly greater and the thermal cracking was very high. To effectively use HSC with a minimal cracking risk, the concrete should be covered with insulation materials during construction. The study is of great significance to notice the engineers to take special measures in the design and construction of modern concrete materials (e.g., high-strength and high-performance concrete) for minimizing risk of cracking in the structures and optimizing the construction schedules.