FE analysis of thermo-hydromechanical behaviour of concrete at high temperature

In the present work an innovative model for analysing the behaviour of concrete in high temperature environment is presented. In such conditions prediction of concrete performance during and after fire exposure is of great practical importance, e.g. in tunnels, as recent fires in major European tunnels have demonstrated. This is particularly true for High Performance and Ultra High Performance concretes, which have been often used in the last decade in nuclear engineering applications, tall buildings and in tunnels, because of their higher tendency to spalling experience. It is now well established that phenomena which take place in concrete exposed to high temperatures, cannot be studied by means of purely diffusive models. In the model presented in this paper concrete is treated as partially saturated porous material where hydration-dehydration, evaporation-condensation, adsorption-desorption phenomena and non-linearities due to temperature and pressure take place. Two applications of this model to an ordinary and HP concrete structure will be shown.