Bond behavior between deformed steel bars and cementitious grout

Abstract

The bond behavior between deformed steel bars and four types of cementitious grout under monotonic loading was investigated in a series of experiments. The effects of testing age and confinement ratio on the bond behavior of the deformed steel bar in the four types of cementitious grout were discussed. The results indicated that the peak bond stress was linearly increased with the increase of time–dependent tensile splitting strength and confinement ratio. The slip at peak bond stress decreased linearly accompanied with the increasing time–dependent tensile splitting strength, and does not seem to be confinement ratio dependent. Moreover, accompanied by the increase of time–dependent tensile splitting strength, the shape parameter of ascending branches of bond stress–slip curves exhibited a linear decrease, whereas the shape parameter of descending branches increased linearly. In addition, with the increasing confinement ratio (1.25 ≤ c/d ≤ 2.5), these two shape parameters stays at a relatively similar values. According to an analysis of the bond behavior of the bond specimens with different test ages and confinement ratios, a peak bond stress model and bond stress–slip constitutive relationships between the deformed steel bars and four types of cementitious grout were proposed. Subsequently, the accuracy of the models proposed in this paper was verified by comparing their results with test results obtained from different sources.