Effect of Freezing Cycles on Bond Strength of Concrete

Experimental observations on the effect of freezing cycles on the bond behavior between steel reinforcement and concrete are reported. Specimens that experienced 1, 10, and 30 freezing cycles are tested under monotonic and reversed cyclic loadings. Results are compared with experimental observations of identical specimens that did not experience freezing cycles. Under monotonic loading the maximum bond resistance decreases as the number of freezing cycles increases. For reversed cyclic loading the average value of bond factors (ratio of maximum bond strengths to compressive strength) in both directions decreases with an increasing number of freezing cycles. In addition, other mechanical properties of concrete experiencing freezing cycles are also determined. It is concluded that cyclic temperature changes do have definite effects on the bond strength of reinforced concrete structures and on the mechanical properties of concrete.