Discontinuos Approach for Meso-Scale Modeling of Porous Materials Like Concrete Under High Temperatures

Abstract

In this work, the failure behavior of concrete exposed to elevated temperatures is analyzed. A thermo-mechanical and poropressure-based interface model for failure analysis of concrete subjected to high temperature is presented. The model represents an extension of a fracture energy-based interface formulation to account for the damage induced by high temperatures and for the temperature dependent pore pressure and humidity in concrete. Thereby, the non-linear response of the proposed coupled thermo-mechanical interface model for porous materials like concrete is activated under kinematic and/or temperature and/or hydraulic increments (with or without jumps). A simplified procedure is proposed to account for the temperature dependent pore pressure in concrete. This contribution focuses on both the formulation of the novel interface constitutive theory and on the strategy proposed for mesoscopic finite element analysis of concrete failure behavior under different hydro-thermo-mechanical conditions. Finally, some numerical analysis are presented which demonstrated the predictive capabilities of the proposed interface model.