Crack spacing model for reinforced concrete tension members based on damage zone and strain compliance concepts

Abstract

A new theoretical model of crack spacing for reinforced concrete tension members is put forward in this study. The model is based on the combination of damage zone and strain compliance concepts for deriving the crack spacing, and it involves the least degree of empiricism. The damage zone demarcates the extent adjacent to cracks over which the bond between concrete and reinforcement is considered to be fully damaged. The strain compliance governs the spatial distribution of strain along reinforcement within the crack spacing with respect to the partial interaction mechanism of bond. Reinforced concrete tension members of known characteristics are designated as reference members, the data from which are related in a unique fashion to the model for deriving the crack spacing formulations for reinforced concrete prisms in general using the load-strain analysis method. The crack spacing obtained from the proposed model enables the proposition of a simple formula for crack spacing estimation taking into account the effects of reinforcement ratio and steel bar diameter.