Experimental study on bond performance between corroded reinforced bar and concrete

Abstract:

To investigate the influence of corrosion on the bond performance between steel bar and concrete, twenty central pull-out test specimens were cast. Pull-out tests were conducted to study the bond behavior between concrete and steel bar corroded using current accelerate method with the expected mass loss of 0%, 0.5%, 1%, 2%, 5%. The variation of the bond performance between steel bar and concrete caused by steel bar corrosion was explained according to the change of steel bar geometrical characters and concrete strength in the whole corrosion process and the influence of corrosion rate on bond stiffness was studied by method of secant bond stiffness. The variation law of cracking due to corrosion expansion, bond stiffness and failure mode with various corrosion levels were studied. The test results show that bond strength and bond stiffness increase at the beginning and then decrease with the corrosion increasing. The degeneration of bond stiffness related to the appearance of cracking due to corrosion expansion. A simplified two-stage test model and conservative model partly available for reference to similar projects were proposed. A bond-slip constitutive relation with different corrosion rates was proposed based on two-stage model.