Constitutive formulation, localization and failure analysis of porous materials like concrete subjected to high temperatura

Abstract

In this work, a thermodynamically consistent non-local poroplastic constitutive theoryfor quasi-brittle materials like concrete subjected to high temperature is presented [1]. Thereby, gradient poroplasticity and fracture energy-based homogenization are combined to describe the post peak behavior of porous media when subjected to long term exposure of temperature. The proposed couple thermo-mechanical material formulation is able to predict the strong variation of sti_ness, strength and ductility of a porous material like concrete in terms of the acting temperature and con_ning pressure. To this end, a temperature dependent maximum strength criterion, and hardening and softening laws are de_ned. The last includes two characteristic lengths describing the non local gradient and fracture energy-based dissipations, respectively, in the post-peak regime.