Abstract

The present work involves calculation and analysis of pore vapor pressure in high strength concrete (HSC) exposed to fire. In order to study the spalling of high strength concrete exposed to fire, a mathematical model of the coupled actions of hydro-thermal effects is established. The temperature field and the pressure field are calculated at a given temperature. Then, the pore vapor pressure is calculated and analyzed and the calculated results are validated experimentally. The relationships between the water permeability coefficient or the vapor permeability coefficient and the peak pressure together with its location are established. The results from this study indicate that peak pore pressure increases with prolonged fire exposure time and shifts from the surface towards the center of the concrete. The research results provide a basis for improving the spalling phenomenon.

Key words: High strength concrete, coupling of water vapor and heat, pore pressure, water permeability coefficient, vapor permeability coefficient.