Crack propagation and size effect in concrete using a non-local damage model

•Influence of size effect on crack opening and crack length is presented.•Experimental crack openings are estimated with digital image correlation technique.•Isotropic non-local damage model is used for numerical simulations.•Optimization algorithm is used for the calibration of material parameters.•Global and local variables of fracture are confronted to the experimental results.

Size effect is a major issue in concrete structures. Experimental and numerical investigations on the influence of size effect on crack opening, crack length and crack propagation are presented in this paper. An isotropic non-local strain softening damage constitutive law is adopted for the numerical model. The material characteristic length is calibrated using an optimization algorithm and a post-processing method is chosen to obtain information on cracking. Numerical global and local results are compared with the experimental data and conclusions are drawn on the advantages and limitations of the adopted modelling strategy to reproduce size effect in concrete structures.