"A study of the effect of crack-induced diffusivity on the service life prediction"

Abstract

The objective of this paper is to propose a numerical model capable of coupling the transfer of chloride ions and cracking into concrete by developing a meso-macro numerical approach for the determination of macroscopic diffusivity tensors in heterogeneous quasi-brittle materials such as concrete. The strong discontinuity kinematics is added to take into account micro-cracking. The mesoscale coupling with the mass transport part is based on Fick’s Law of diffusion with a modified diffusion coefficient accounting for crack opening and aggregates by means of the experimental results of Djerbi et al. [DJE 08]. Then an upscaling process based on the work of Pouya et al. [POU 02] is used to provide a macroscale diffusivity (mean diffusivity tensor). Finally, the obtained mean diffusivity tensor has been employed to predict the corrosion initiation time to study the impact of mechanical cracking on service life of RC structures using Bazant’s physical models. The numerical results show an induced-anisotropy of the mean diffusivity tensor and obvious effect of the value of crack opening on the corrosion initiation time.