Concrete cover tensile capacity of corroded reinforced concrete

In this paper, the concrete cover tensile (CCT) capacity of cracked concrete caused by reinforcement corrosion is investigated. A newly developed double-cylinder model with the consideration of concrete confinement effects is used to evaluate the critical expansive pressure of the corrosion products necessary to cause unstable cover crack propagation in corroded reinforced concrete. After considering the critical pressures associated with wide ranges of tensile capacities of concrete, reinforcement diameters and cover thicknesses, an empirical critical expansion pressure function is determined by the least squares method. The CCT capacity of cracked concrete is obtained by considering the equilibrium of expansive pressure and concrete resistant tensile force at the limiting stage. A generic relationship between CCT capacity and concrete cover in a bilinear form, which is suitable for the design, analysis and modeling of the problems related to reinforcement bar corrosion induced and other internal expansion-caused cover cracking, is proposed for the first time. Parametric studies are conducted to investigate the effects of the tensile strength of concrete and cover thickness on the critical expansive pressure and CCT capacity.