COMPUTATIONAL FAILURE ANALYSIS OF CONCRETE UNDER HIGH TEMPERATURE

G.J. ETSE; M. RIPANI; J.L. MROGINSKI

COMPUTATIONAL MODELLING OF CONCRETE STRUCTURES

Taylor & Francis Group

Año: 2014; p. 715 - 723

A gradient and fracture energy-based thermodynamically consistent model for concrete is considered to evaluate the degradation of mechanical properties when this material is subjected to high temperature fields. The model considered in this work, recently proposed by the authors (see Ripani et al. (2014)), includes a local isotropic hardening formulation to predict the degradation of concrete mechanical properties in the prepeak regime, which depends on both the acting confining pressure and temperature. Concrete strength after peak is decomposed into two additive components in the framework of a parallel mechanism. On one hand, a strength contribution from the material located in between cracks which is modeled by means of a non-local gradient theory. And, on the other hand, the strength to further develop existing cracks and/or to open new cracks. After a short description of the model formulation, the attention focuses on the numerical analysis and predictions of concrete degradation process and failure behavior when it is subjected to combined mechanical and thermal action. In particular, the differences in the failure behaviors of concrete components in tension and compression under high temperatures are evaluated as well as the thermal effects on concrete components when they are subjected to increasing temperature under constant loads.