EXPERIMENTAL STUDY ON BOND-ANCHORAGE PROPERTIES OF HRB HIGH-STRENGTH STEEL BARS IN CONCRETE AFTER HIGH TEMPERATURE

Based on 45 HRB high-strength steel bar specimens pull-out tests after high temperature,it is studied that the bond-anchorage properties of high-strength steel bars and the main factors influencing the bond capacity between high-strength steel bars and concrete. During the experiments,the reinforced concrete specimens were heated at 200, 400 and 600 ℃,respectively,cooled in air and subjected to monotonic pull-out loading. The influencing regulations of some factors on the bond-anchorage properties of high-strength steel bars are investigated,such as concrete strength,yield strength of reinforcing bar,stirrup ratio. At the same time,the paper clarifies that the major bondanchorage mechanism of high-strength steel bars after high temperature is similar to that of the general reinforcement.