Experimental Research On Bond Behaviors Between Frozen-thawed Concrete And Deformed Steel Bars Under Cyclic Loading

It is a vast territory in China while some areas are in the cold zone. Concretebuilding in these areas often suffer from freeze-thaw damage, which has a significantimpact of the performance of concrete. Currently, scholars whether in China or inwestern countries have rarely carried out research work which is the seismicperformance of concrete structures after freezing and thawing.In this paper, firstly concrete specimens of three concrete strength C30、C40、C50were subjected to rapid freeze-thaw cycle test of0times,100times,200times and300times，analyzing and summarizing the experimental results. On this basis, we canget the relationship between concrete compressive strength，mass loss rate，the relativedynamic modulus and the freeze-thaw times under different concrete strength conditions.Then to load the specimen, obtained the bond-slip curve of different concrete strengthand different freeze-thaw times under monotonic and cyclic loading.Secondly, monotonous loading experimental data were analyzed, summarizingcurves characteristic, getting the relationship between the maximum bond strength, themaximum slip, the residual strength and freeze-thaw times under different concretestrength conditions; After the analysis of the cyclic loading experimental data,comparing test data with the result of monotonous loading experimental data,introducing bond degradation rate, the degradation rate of frictional resistance andresidual bond stress degradation rate, getting the relationship between them andfreeze-thaw times under different concrete strength conditions.Finally, based on test data,establishing bond slip constitutive relation undermonotonic loading and deformation of reinforced concrete freezing and the cyclic loading curve bond slip constitutive relation under cyclic loading and deformation ofreinforced concrete. By introducing the key parameters and residual adhesion stress rateand loss bond degradation rate,getting the bond slip constitutive relation under cyclicloading and deformation of reinforced concrete.