Effect Of Steel Fiber On Corrosion And Bond Properties Of Steel Bars In Concrete

The bond performance is the premise that the reinforcement and concrete can cooperate,and its performance directly affects the mechanical performance of reinforced concrete structure.The corrosion of steel bars will affect the bond performance between the reinforcement and the concrete.Adding some steel fiber into the concrete can improve the tensile performance of the concrete,restrain the crack and significantly improve the bond performance between the reinforcement and the concrete.But the addition of steel fiber will enhance the conductivity of concrete and accelerate the corrosion of steel bars in the test piece.Therefore,this paper has carried out the related research work,the main contents are as follows.(1)The longitudinal bars in the specimen were accelerated by electrochemical corrosion method,and the changes of surface and current and voltage were observed during the corrosion.It is found that the time of rust expansion crack of the sample mixed with steel fiber is longer;The influence of steel fiber on the corrosion rate of longitudinal bars in the specimen is irregular.(2)The influence of steel fiber content on the bond performance of corroded steel and concrete under stirrup restraint is studied.The results show that the bond strength of he corrosion free specimens increases first and then decreases with the increase of fiber content,and the performance of steel fiber is the best when the content of steel fiber is 0.8%;When the corrosion rate is 0-2.5% and 2.3%-4.5%,the bonding strength increases first and then decreases with the increase of fiber content,and the performance of steel fiber is the best when the content of 12% is increased,When the corrosion rate is 4.53%-6.7%,he bond strength increases with the increase of fiber content,and the best performance is when the steel fiber is1.6%.3)The influence of corrosion rate on e bond performance of reinforced concrete and fiber reinforced concrete is studied.The results show that the bond strength of the fiber-free specimens decreases with the increase of corrosion rate;the bonging strength of 0.8% and 1.2% steel fiber specimens increases first and then decreases with the increase of corrosion rate: The bonding strength of the steel fiber specimens added1.6% increased with the increase of corrosion rate.(4)The data measured in this experiment are fitted by the bond slip stress relationship between Haraji and Zhenhai Guo,and the suggested vales of.each parameter are given.