Effect Of Seawater Corrosion On The Bond Behavior Between The Hybrid Fiber Reinforced Concrete Properties And Steel Bars

The durability of reinforced concrete structures is the focus of attention in the engineering world under the environment of seawater corrosion.Among the factors that affect the durability of concrete structure,the corrosion of steel bar is the most significant.After the corrosion of steel bar to a certain extent,the bond performance between concrete and steel will decrease,which will lead to a significant reduction in the bearing capacity of the whole structure.It is very important to study the bond behavior of corroded steel bar and concrete in the seawater corrosion environment.Cracks will accelerate the process of steel corrosion,and steel corrosion will have a negative impact on the bond,Therefore,the key of slowing down the bond performance degradation between the steel of corrosion and concrete is control the development of cracks in concrete,adding fiber to concrete can restrain the expansion of cracks in concrete.Hybrid fiber reinforced concrete is a kind of material which is composed of two or more than two kinds of fiber with a certain volume ratio in the concrete,Compared to the single fiber concrete,Hybrid fiber reinforced concrete has a very good positive effect,which can better constrain the development of concrete internal cracks,so as to improve the bond between the steel and concrete performance.In this paper,corrosion percentage ranged from 0 to 6.89% of steel bar for pull out specimens was controlled by electrochemistry accelerated method.By the center pullout tests of reinforced concrete specimens,the bond behavior between different corrosion percentage of bars,different fibers volume fraction of hybrid fibers reinforced concrete and the kind of steel bars was discussed.Based on the tests results,the degradation of the formula of the ultimate bond strength between hybrid fiber reinforced concrete and steel bars was proposed,and based on the summary of previous research results,The mathematical model of bond slip between hybrid fiber reinforced concrete and steel bar was fitted.The results showed that in a certain range,with the increase of hybrid fiber volume fraction,the bond behavior between steel and concrete gradually increase,the bond strength increases firstly and then decreases sharply with the incensement of corrosion percentage.the bond property of deformed bar is better than plain bars.In addition to the test,using ABAQUS finite element software,the pull-out test of hybrid fiber concrete and deformed bar was simulated and in all levels of drawing load,the bond load between the hybrid fiber reinforced concrete and steel bar and the slip of steel bar loading end were calculated.The test results and simulation results are compared,and the error is within the reasonable range,which verify the feasibility of using ABAQUS simulation and lays a foundation for further research on the bond performance of hybrid fiber reinforced concrete and steel bar.