Numerical modelling of moisture ingress in cracked concrete

Abstract

Concrete is a construction material which service life can be significantly reduced with the presence of cracks when concrete is exposed to aggressive agents such as chlorides. The current service life models for concrete do not account for cracks when modelling service life of concrete structures. In this thesis, moisture transport in concrete with a crack and aggregates was modelled numerically using finite element analysis. The numerical model was applied to a wedge spitting test geometry and tested against experimental data, and was used to identify how the crack and aggregates influence moisture ingress. The numerical model was able to model the ingress extend in vertical and lateral directions with a very good agreement with the experimental data, both for the un-cracked and cracked state. The moisture distribution was more accurately modelled with the heterogeneous models including aggregates compared to the homogenous models without aggregates. By observing the behavior of the numerical model when varying the number of solutions that is interpolated and averaged to give rise to the heterogeneous models including aggregates, it was found that the heterogeneous models converge towards the homogenous models, when the number of interpolated solutions that are included go towards infinity.