Finite element simulation of restrained shrinkage cracking of cementitious materials: Considering moisture diffusion, aging viscoelasticity, aleatory uncertainty, and the effects of soft/stiff inclusions

Simulation of restrained ring shrinkage and cracking of cementitious materials in a multiphysics simulation framework (MOOSE) is discussed in this paper. The 3D numerical model analyzes residual stress development and crack initiation/propagation in cement pastes by applying an eigenstrain which varies over the depth of the specimen based on the relative humidity of the pores as moisture diffuses from the drying surface. The numerical modeling framework explicitly considers: (i) moisture diffusion that generates differential shrinkage along the depth of the specimen (ii) viscoelastic response of aging cementitious materials through a rate-type creep law based on generalized Maxwell model, (iii) isotropic damage model with Rankine′s criterion determining the failure initiation, and (iv) aleatory uncertainty-based distribution of tensile strengths of individual finite elements to account for statistical variability and associated microstructural size effects. The model is implemented for cement pastes containing compliant/stiff inclusions subjected to variable drying conditions. The numerical model can be used to compare the cracking propensity of different cementitious mixtures.