BOND PERFORMANCE BETWEEN SLIGHTLY CORRODED STEEL BARS AND CONCRETE AFTER EXPOSED TO HIGH TEMPERATURES

The influence of high temperature exposure on the bond strength between corroded steel bars and concrete was investigated using pull-out tests. After being exposed to temperatures of (20℃, 200℃, 400℃, 600℃ and 800℃), the bond strength between concrete and reinforcing bars with reinforcement mass loss percentages of 0% and 1.08% was tested. The experimental results indicated that the ultimate bond strength between reinforcement and concrete decreases with the increasing temperature. The ultimate bond strength of the corroded specimens had less strength loss compared to the un-corroded specimens as the temperature was below 400℃. The variation laws of the compressive strength of concrete, the ultimate strength of steel bars and the bond strength between steel bars and concrete were analyzed after the specimens being exposed to high temperatures. Besides, the bond-slip relationship considering the influence of the temperature and corrosion is established.