Research On Bearing Capacity Of Concrete Columns Under The Coupling Action Of Corrosion And Load

As a typical load-bearing component,reinforced concrete columns are widely used in civil engineering construction.With the large-scale construction of reinforced concrete structures and the increase in service life,especially the long-term service in deicing salt and marine climate and other chloride salt erosion environments Structure and its durability will become increasingly prominent.Therefore,it is necessary to study the durability of reinforced concrete columns under the coupling effect of corrosion and load.In this paper,through the ultimate bearing capacity test of reinforced concrete columns under the coupled environment of corrosion and load,by studying the uneven corrosion distribution of steel bars,and combining the bond degradation relationship between steel bars and concrete,it is concluded that corrosion and load coupling The ultimate bearing capacity model of reinforced concrete columns,the research contents and conclusions are mainly as follows:(1)Conduct corrosion analysis on the test steel bars and observe the corrosion distribution of the steel bars.It is found that under the simulated chloride salt environment corrosion conditions,the steel bars have relatively serious uneven corrosion.The specific performance is:the outer side of the steel bar close to the corrosive environment is severely corroded,and the inner side of the steel bar far away from the corrosive environment is slightly corroded.The distribution model of steel bar corrosion under different corrosion conditions is established,combined with the bond degradation law between steel bar and concrete,it is concluded that the bonding force of steel bar will not degrade under low corrosion conditions(10%),and the bonding force will degrade under high corrosion conditions(20%)in conclusion.(2)Considering the three factors of eccentricity,loading age and corrosion rate,the ultimate bearing test of the specimens was carried out.The study found that:in the case of low corrosion,the corrosion of steel bars will not cause bond degradation and damage to the concrete structure,so the test The load-bearing capacity of the parts has not decreased significantly.In the case of high corrosion,steel corrosion will not only cause material performance degradation,but also steel corrosion products will also damage the concrete structure,reducing the effective cross-section of the specimen,resulting in a significant reduction in bearing capacity.At the same time,the long-term effect of eccentric load will limit the limit of the specimen.The bearing capacity has a significant impact.(3)Combining the uneven corrosion of the steel bars in the test piece and the bond degradation of the steel bars,a calculation model for the ultimate bearing capacity of concrete columns under different corrosion rates and eccentricity is established.The calculated value of the model is relatively close to the measured value in the test,and the error is reasonable.The scope can provide a theoretical basis for the durability evaluation of the building structure under the chloride salt corrosion environment.