Temperature field in mass concrete at early-age: Experimental research and numerical simulation

It is well-known that the hydration of concrete mixture at an early age plays a crucial role in leading to a rise in temperature in massive concrete structures. In addition, thermal stress caused by the temperature difference between the center and the surface of a concrete solid is a crucial reason in making thermal cracking when its stress exceeds the tensile strength of concrete. Therefore, the purpose of this paper is to determine the maximum temperature and the temperature difference in mass concrete with varying scenarios of initial temperature by the use of the finite element Midas Civil code in combination with experimental data. In which, a B30-grade concrete with a water/cement ratio of 0.39 was designed with some temperature sensors for the experimental works. A 3D model mesh of the concrete foundation with 1920 elements and 2509 nodes was used to simulate the scenarios of initial temperature.To verify the accuracy of the finite element simulation results, the simulation results are compared with the measurement results at the construction site. The comparison between the temperature field of simulation with measured temperatures from corresponding sensors was made. It is interesting to found that the difference between the results of measurements and the results of finite element simulation was insignificant. Thus, the finite element method not only gave an accurate prediction of thermal distribution and stress state but also provided a potential indication of cracking ability of concrete at an early age. Furthermore,the analysis results pointed out that the appropriate condition for placing temperature of mass concrete was tpl = 30oC and also suggested an effective way to control thermal cracking in the mass concrete structure at early-age. © 2020, Research Trend. All rights reserved.