A numerical model for the time-dependent cracking of cementitious materials

A uni;ed ;nite element formulation is presented for the analysis of the time-dependent cracking of cementitious materials. The rate-type constitutive law incorporates linear visco-elasticity and continuum plasticity. The former accounts for the bulk creep via a Maxwell chain, while the latter describes crack initiation and propagation via a softening, anisotropic Rankine yield criterion. The rate dependence of bond ruptures leading to fracture is accounted for by considering the viscosity of the cracking process. This contribution to the cracking resistance also regularises the localisation process. It is demonstrated how other important phenomena in cementitious materials, such as stress-dependent hygral and thermal shrinkage, can be incorporated into the computational framework