Experimental and numerical investigation of corrosion-induced cover cracking in reinforced concrete structures

In the paper corrosion-induced crack initiation and propagation are investigated experimentally and numerically, with particular emphasis on quantifying the proportion of corrosion products that are dissipated within the concrete pores and cracks, thus reducing the pressure exerted by corrosion products on the surrounding concrete. Initially, experimental data on crack initiation and propagation obtained from accelerated corrosion tests of reinforced concrete slabs are presented. A comparison of finite-element model results and experimental data is used to estimate the amount of corrosion products penetrating into concrete pores and cracks, which is an essential parameter for prediction of corrosion initiation and propagation. It was found that the amount of corrosion products penetrating into the concrete pores before crack initiation is larger than that obtained by other researchers. The paper also showed that corrosion products do not fully fill corrosion-induced cracks in concrete immediately after their initiation as the cracks are being filled gradually over time and the thicker the concrete cover the longer it will take to fully fill a crack.