MESO-SCALE INVESTIGATION ON THERMAL CONDUCTION BEHAVIOR IN CONCRETE WITH MECHANICAL DAMAGE

To investigate the effect of mechanical damage on thermal conduction, a mesoscopic method was proposed in the present work considering the heterogeneity of meso-structure. In this study, concrete was considered as a three-phase composite material consisting of aggregate, mortar matrix and interfacial transition zones (ITZs) between them. The mechanical analysis was conducted first to study the damage distribution within the concrete. Subsequently, the outcomes of mechanical computation were used as the initial input data in the thermal conduction computation. The current thermal conductivity of damaged element was homogenized by a composite mechanical method based on damage and the initial thermal conductivity of sound material. It is in this way that the mechanical and thermal behavior were coupled. The present model was calibrated by comparing the numerical results with available experimental data. Based on the verified simulation method, effective thermal conductivity (ETC) and temperature field of concrete subjected to compressive loadings were calculated. In addition, the effects of different composite mechanical models were analyzed and the influence of compressive loading levels was explored.