Abstract:To explore the bond slip behavior and constitutive relationship between the steel bar and the concrete under the deicer frost environment, through the self made bidirectional compression type of reinforced concrete pull out device and the test method in which strain gauges were pasted on the inner milling slot of steel bars, pull out tests were conducted on reinforced concrete specimens subjected to salt freezing cycles. Research results show that with the increase of salt freezing cycles, the ultimate bond strength decreases linearly, the initial sliding load of free end drops gradually, the slippage of free end corresponding to the ultimate bond stress decreases first and then increases; the peak value of bond stress spreads from the loading end toward the free end with increase of loading, the spreading tendency of the peak value is more and more obvious with the increase of degree of freezing thawing damage. Distribution laws of bond stress and slippage along anchorage length are obtained through theoretical analysis. Based on the above work, the reinforced concrete bond slip constitutive equation is established under deicer frost action with considering the position function, which could provide theoretical evidences for the reinforced concrete finite element analysis and the durability assessment under chloride environment of the cold region.