Corrosion-Induced Cover Cracking: New Test Data and Predictive Models

Abstract

Corrosion, especially in chloride environments, can contribute to cracking of reinforced concrete (RC) structures. In this paper, accelerated corrosion tests of reinforced concrete slabs were conducted to develop a new empirical model to predict the timing of corrosion-induced cover cracking for RC structures in chloride environments. The accelerated corrosion experimental program measured concrete cover cracking for RC slab specimens based on various concrete covers, concrete tensile strengths, and reinforcing bar diameters. A correction factor for concrete confinement is proposed to account for bars located at edges and corners. A rate of loading correction factor is applied to allow the cracking times for accelerated corrosion rates to be adjusted for the lower corrosion rates generally found in RC structures. A statistical analysis of model accuracy is used to account for variabilities between experimental data and model predictions. The new model is shown to be particularly sensitive to cover and reinforcing bar diameter.