Prediction of the permeability of damaged concrete using a combined lattice beam-crack network approach

Abstract

The article describes a combined damage and permeability 3D model for concrete. The model aims at predicting the permeability of damaged concrete. For the mechanical model a lattice of beam elements was used in which the damage was simulated by a stepwise removal of beams. For the computation of the permeability, the beams removed were connected by transport elements with an aperture proportional to the relative displacement between the nodes previously connected by the beams. The numerical simulations were then compared with experimental results from a diffuse tensile cracking and permeability test. The results of two lattice models were compared with experimental results: i) one where the concrete was considered as a homogenous material; and ii) one where the aggregates were individually modeled. The results show that when the aggregates are included, the simulation agrees better with the test results for low strain values, while for higher strains the homogeneous model is in better agreement.