Bond behaviors between copper slag concrete and corroded steel bar after exposure to high temperature

Abstract

In this paper, the experimental investigation on degradation law of bond behaviors between copper slag concrete and corroded steel bar after exposure to high temperature was conducted. The bond behaviors such as bond strength, bond stiffness, peak slip displacement and average bond stress-slip curve between copper slag concrete and corroded steel bar after heating were analyzed with the change in heating temperature and corrosion rate of steel bar. Moreover, the distribution of free chloride ion in concrete was measured and the chloride ion diffusion coefficient was also calculated. At last, the bond-slip constitutive model suitable for high temperature damaged concrete and corroded steel bar was proposed. The test results showed that the chloride ion diffusion coefficient of high temperature damaged copper slag concrete increased with the increasing of copper slag replacing ratio and heating temperature. The bond strength between copper slag concrete and corroded steel bar decreased with the increasing of heating temperature and corrosion rate of the steel bar and decreased at an accelerated rate with the increasing of the copper slag replacing ratio, and the peak slip displacement gradually increased as the heating temperature increased. However, the bond stiffness increased first and then decreased with the increasing of heating temperature, and the bond stiffness also increased with the increasing of copper slag replacing ratio. At last, the accuracy of the bond-slip constitutive model established based on the test results was verified.