Numerical modelling of the fire behaviour of reinforced concrete beam integrating the concrete cover lost by spalling

The aim of the paper is the realization of a numerical study,in which the concrete spalling phenomenon of structural elements (beams) in reinforced concrete subject to hydrocarbon fire (hc) is considered,and its influence on structural stability is analyzed. the manifestation of this phenomenon can start during the first few minutes,exposing the reinforcement nearest to the fire,and it subsequently accelerates the loss of resistance,thus causing premature failure of the structure. taking into account the spalling risk of concrete,various regulations are often based on experimental approaches,and therefore no predictive calculation can yet be realized. the accurate prediction of this phenomenon remains unknown. in the context of this work,the safircode may be used to perform a numerical analysis of the spalling risk,by removing layers of concrete covering when a set of spalling criteria are checked. the parametric study focused on: the generalization of the spalling along the element or not,taking account of spalling which occurs on one or more sides of the element,and the influence of various parameters such as changes in boundary conditions and reduced mechanical properties of materials as a function of changes in temperature. the results obtained show the major influence of spalling on the mechanical stability of structural elements in a fire situation,and that this is by reducing the failure time and/or by reducing the yield strength and tangent modulus. © 2017,university of mohammed premier oujda morocco.