Abstract
The influence of the stress in a direction perpendicular to the bar on bond strength has already been studied a lot in association with lateral reinforcement, however, the influence of the axial stress has not been clear yet. In this study, a brush type loading equipment was used in order to reduce the friction and pull-out tests were conducted with the concrete under axial compression. The parameters were concrete cover thickness, lateral reinforcement ratio, and axial force ratio. The results show that bond strength decreases with the increase in the axial force ratio in the case of no lateral reinforcement, and the load with which the first crack occur decreases with the increase in the axial force ratio regardless of the exist of lateral reinforcement.
