Moisture propagation and resulting stress in heated concrete walls

Abstract

A mathematical model to simulate the coupled heat and mass transfer in heated porous media, as well as the resulting stress, is described. A finite element analysis, assuming homogeneous elastic material, is used to study the temperature and pore pressure distribution, and the rate of moisture propagation through a concrete containment wall under different time-dependent temperature boundary conditions. Results are also presented for the internal stresses caused by the presence of temperature gradients, pore pressure and the release of chemically bound water at high temperatures. Stress analysis calculations are superimposed over the calculations of the moisture propagation. The temperature, pore pressure and volume change resulting from the loss of bound water, as derived by the thermal mass transport calculation, are used as input for the stress analysis.