Experimental investigations on bond behaviour of reinforced concrete under transverse tension and repeated loading

In order to evaluate the bond behaviour between ribbed bars and normal strength concrete under transverse tension and repeated loading, pull-out tests with cyclic tensile loading and different preadjusted crack widths along the pull-out bar have been conducted. The cyclic tests with one million load cycles have been carried out on two different load levels with two different crack widths. The paper provides a detailed presentation of the test results. In comparison to the different loading conditions, the slip increase between reinforcing steel bar and concrete, depending on the number of load cycles, was taken into account. The test results show a great influence of longitudinal cracks on bond behaviour under cyclic loading. The wider the longitudinal crack widths due to transverse tension, the more the slip increases and the earlier the bond failure occurs.