A new method for hydraulic mass concrete temperature control: Design and experiment

In this paper, a new method for hydraulic mass concrete temperature control to reduce temperature stress is proposed. Based on dam temperature distribution characteristics, an external heating and cooling source is used to make the water circulate in the pre-embedded pipe net in the concrete surface layer to control the concrete temperature. The minimum adverse strain principle is used to design the key parameters of the control system, and the strain caused by temperature and moisture is considered because of the porousness of concrete. The feasibility of the new method is studied via a mass concrete (1 m x 1 m x 1 m) experiment with pre-embedded temperature and moisture sensors under cold environmental conditions. The temperature and moisture evolutions in the control process show that the concrete temperature can be effectively controlled by the new method, but temperature control also has a great effect on the moisture in the surface layer concrete. Considering that the decreasing moisture of surface layer concrete in the temperature control process can also lead to adverse strain, based on the coupled heat and moisture transfer theory, the key parameters of the control system in the experiment are studied and optimized via simulations to reduce adverse strain.