Modeling of fluid leakage through multi-cracked RC structural elements using a numerical probabilistic cracking approach

Abstract

An experimental and finite element study on water leakage through reinforced concrete structural elements is presented in the paper. A macroscopic probabilistic approach is used to predict structural transfer properties evolution induced by concrete cracking. In this model, material heterogeneity is taken into account by randomly distributing the mechanical elementary properties (tensile strength, cracking energy) over the computational mesh. Each finite element is considered as representative of a volume of heterogeneous material, whose mechanical behavior depends on its own volume. The parameters of the statistical distributions defining the elementary mechanical properties thus vary over the computational mesh element-by-element according to experimentally validated constitutive laws. Under a weak hydro-mechanical coupling assumption, the model considers that the mechanical cracking of a finite element induces loss of isotropy of its own permeability tensor. So, at the finite element level, the localized crack flow is smeared over the elementary volume. Its contribution is computed according to an experimentally enhanced parallel plates model. An experimental test, which studies the real-time water transmissivity evolution of reinforced concrete tie-specimens under uniaxial tensile loading, is numerically simulated. Constitutive hydro-mechanical parameters were calibrated in previous works for a given concrete formulation. So, in order to avoid of any adjustments in the model parameters, the reference experimental test was performed with the same concrete formulation as in previous phases of the research. Numerical results evidence that, once steel–concrete interface is properly treated, a probabilistic approach can lead to proper predictions of cracking and its effect on fluid leakage.