Mechanical stresses and crack analysis of concrete under the hygrothermic effect

The hygrothermal process can change the porosity and the permeability of concrete, causing the initiation and the growth of the cracks, and thus deteriorating the integrity of the concrete structure. A numerical formulation based on the finite element method is developed to carry out the simulation of the initiation and the propagation of the cracks caused by the coupled field of thermal transfer and moisture transport. An original concept based on three-dimensional stress state of the integration points in each finite element is described. The global relative crack density is used to denote the cracking state of the entire concrete structure, which may serve as an appropriate index to evaluate the overall deterioration level of the structure.