Experimental investigation of corrosion effect on bond behavior between reinforcing bar and concrete

Abstract

An experimental study is conducted in this paper to investigate the effect of corrosion and corrosion-induced cracks on the bond behavior between steel bars and concrete. An accelerated corrosion test was used to corrode the steel bars embedded in concrete specimens under laboratory condition. Two series of pull-out tests were designed. Pull-out tests on the specimens with plain and deformed reinforcing bars are performed. The bond behavior of the two types of steel bar specimens including the ultimate bond strength, bond-slip relationships for different corrosion levels are discussed. An empirical bond degradation model is proposed combining a wide range of experimental data available in the literatures. The other pull-out tests on the bonding specimens with interior strain gauges are conducted and the bond stress at various positions are derived based on the observed reinforcement strains. The experimental results show that the corrosion influence on bond strength can be ignored when the corrosion loss is less than 2.4%. The bond behavior between smooth bar and concrete is more sensitive to the corrosion than that of specimen with deformed bar. The selection of steel bars is also an alternative way to improve the bond behavior especially for the deformed bar specimens. The distribution of bond stress is more uniform for the specimen with a large corrosion-induced crack width.