Thermo-mechanical model for the material nonlinear analysis of cement based materials

Since most advanced cement based materials have relatively high binder content, the risk of cracking at an early age should be evaluated using models that can estimate the heat generated by the hydration of pozolanic components and the induced stress fields. For this purpose, a general thermal model was developed, in order to perform steady state thermal analysis, transient linear thermal analysis and nonlinear thermal analysis. The heat development due to the hydration process during the concrete hardening phase is coupled with the thermal model, leading to a numerical approach that is capable of simulating the behavior of concrete structures since its early ages. This thermal model is integrated into a mechanical model that can simulate the crack initiation and propagation in structures discretized with solid finite elements. The mechanical model is a 3D multi-directional smeared crack model with the capability of simulating the behavior of structures failing in flexure, shear or punching. The thermo-mechanical model is presented and its performance and accuracy are assessed by simulating a case study available in the literature.Financial support of FCT, PhD Grant number SFRH/BD/23326/2005. The authors acknowledge the support provided by SUPERCONCRETE Marie Sklodowska-Curie Actions, Research and Innovation Staff Exchange (RISE), proposal 64570