Computer Simulation of Hygro-Thermal Phenomena in High Performance Concrete at High Temperature

Some results, obtained by use of a new mathematical model for analysis of heat and mass transfer in concrete at high temperatures, are presented. High temperature effects are considered by means of temperature and pressure dependence of several material parameters. Effect of damage on intrinsic permeability of concrete is taken into account. On the basis of the mathematical model, the computer code HITECOSP for analysis of spalling phenomena in concrete was developed by authors of this paper in the framework of BRITE Euram III BRPR-CT95-0065 HITECO programme. Necessary for computations, material parameters for some types of HP Concrete were measured by several European laboratories, which participated in the project. The code was calibrated with some available experimental data concerning high temperature behaviour of concrete walls, cylinders, columns and special structures, like tunnel sectors and nuclear waste containers. Two numerical examples concerning behaviour of HPC structures during fire are presented in order to demonstrate capabilities of the computer code.