Effect of the interaction of corrosion pits among multiple tensile rebars on the reliability of RC structures: Experimental and numerical investigation

The deterioration of reinforced concrete (RC) structures due to chloride-induced corrosion is not spatially uniform because of the spatial variability related to material properties and environmental stressors. This variation has a substantial effect on the reliability of RC structures. However, few experimental studies have focused on the effect of the interaction of corrosion pits among tensile rebars on the reliability of RC structures. Therefore, in this paper, an experimental procedure that incorporates X-ray and digital image processing techniques was conducted on RC slab specimens subjected to accelerated corrosion. Using the experimental results, the parameter of the transverse correlation function of steel weight loss distributions was estimated to investigate how the corrosion pits in corroded rebars are correlated. Based on the experimentally obtained model parameters, the spatial steel weight loss distributions were simulated by spectral representation method. A three-dimensional (3D) nonlinear finite element (FE) analysis of RC structures with simulated steel weight loss distributions was conducted to obtain the ultimate bending capacity of RC structures. In an illustrative example, the effect of the transverse correlation among steel weight loss distributions of multiple tensile rebars on the failure probability of RC girders was quantified.