Local bond-stress–slip relationships under repeated loading

Abstract

Synopsis Pull-out specimens in which the reinforcing bar was embedded for 38 mm were tested under nine slow load cycles of constant amplitude in order to determine the effect of repeated loading upon the local bondstress–slip relationships for deformed bars. The local bond-stress–slip curves obtained under repeated loading form hysteresis loops and have residual slip at zero load. The results show that bond effectiveness is particularly sensitive to the magnitude of the peak stress reached in preceding cycles. Load cycling of constant amplitude produces only a gradual deterioration of bond. The curves can be used for modelling bond at the steel–concrete interface in finite-element analyses of reinforced concrete members.