MOISTURE PROPAGATION AND RESULTING STRESS IN HEATED CONCRETE WALLS

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 us ed to study the temperature and pore pressure distribution, and the ra te of moisture propagation through a concrete containment wall under d ifferent time-dependent temperature boundary conditions. Results are a lso presented for the internal stresses caused by the presence of temp erature gradients, pore pressure and the release of chemically bound w ater at high temperatures. Stress analysis calculations are superimpos ed over the calculations of the moisture propagation. The temperature, pore pressure and volume change resulting from the loss of bound wate r, as derived by the thermal mass transport calculation, are used as i nput for the stress analysis.