Finite-Element Modeling and Calibration of Temperature Prediction of Hydrating Portland Cement Concrete Pavements

摘要

The temperature profiles in a hydrating concrete slab are produced by a two-dimensional finite-element method software tool, TMAC~2 (temperature and moisture analysis for curing concrete), as a function of time and ambient boundary conditions described in this paper. To include the effect of the heat of vaporization, heat flux due to evaporation is included in the boundary condition of heat transfer at the slab surface in addition to the effects of surface humidity, effective curing thickness, and surface moisture emissivity on the rate of evaporation. Thermal conductivity is back-calculated using the data collected from laboratory measurements toward the improvement of the modeling of thermal conductivity. Theoretically, the material properties determined in this manner should facilitate accurate temperature prediction. Thus, temperature prediction in hardening concrete pavements under various conditions can be effectively calibrated by improved material characterization. To this end, this paper provides the basis of a calibration protocol.