Cracking and Bond Slip in Concrete Beams

Based on an assumed model of crack formation, expressions are developed for maximum crack spacing and crack width in reinforced concrete beams in pure flexure. Both the maximum crack width at the tension surface of the member and the maximum crack width at the surface of the reinforcement are considered, and the former and an upper bound on the latter are related to the crack spacing through a slip modulus between the concrete and the steel. Various physical parameters involved in the expressions are evaluated by use of elastic finite element analysis and through statistical analysis of crack measurements available in the literature. These data are then used to provide approximate expressions which make it possible to predict maximum crack width at the surface of the reinforcement and at the tension surface of flexural members.