Critical Crack Depth in Corrosion-Induced Concrete Cracking

Practical experience and observations suggest that corrosion affected reinforced concrete (RC) structures are more prone to cracking than other forms of structural deterioration. Once a crack initiates at the steel-concrete interface, it will propagate to a critical depth at which the crack becomes unstable and suddenly propagate to the concrete surface. This paper aims to develop an analytical method to predict the critical crack depth in corrosion-induced cracking of reinforced concrete structures. This method is derived based on fracture mechanics whereby the stress intensity factor for a single radial crack in a thick-walled cylinder is first determined using the weight function method. It is found that the critical crack depth occurs at the same point regardless of the tensile strength but increases with the increase in concrete cover. It is also found that the concrete cover significantly affects the maximum internal pressure compared to concrete tensile strength.