摘要：Severe micro-structural changes that alter the physical- mechanical behavior of concrete are induced by high temperatures. The porous structure and threfore physical properties of concrete change with time following the hydrate and aging processes evolution and they are strongly influenced not only by mechanical load and higro-thennal state but also by their time histories. A thermo-mechanical model for concrete exposed to high temperatures is presented in this paper. The model is based on a plastic-damage model extended to take into account the effect of the cement paste dehydration produce by high temperatures. Thermodynamic bases of the model are first presented followed by the description of the numerical approach used to solve the coupled thermo-mechanical problem. Finally application examples and comparison with experimental results of concrete elements exposed to high temperatures that allow validating the proposed model are presented.
其他摘要：Severe micro-structural changes that alter the physical- mechanical behavior of concrete are induced by high temperatures. The porous structure and threfore physical properties of concrete change with time following the hydrate and aging processes evolution and they are strongly influenced not only by mechanical load and higro-thennal state but also by their time histories. A thermo-mechanical model for concrete exposed to high temperatures is presented in this paper. The model is based on a plastic-damage model extended to take into account the effect of the cement paste dehydration produce by high temperatures. Thermodynamic bases of the model are first presented followed by the description of the numerical approach used to solve the coupled thermo-mechanical problem. Finally application examples and comparison with experimental results of concrete elements exposed to high temperatures that allow validating the proposed model are presented.
