Study On Impact Resistance Of Steel Fiber Reinforced Rubber Concrete

In our country,the rivers in Xinjiang and Southwest Region are mostly mountain rivers with steep slopes and rapid currents,which load and suspended load content is larger.Hydraulic discharge structures built on such rivers will not only be subjected to the impact of small particle size suspended load,but the impact of large particle size load.Rubber concrete is a new type of high anti-abrasion concrete.Although its impact resistance is better than that of ordinary concrete of the same grade,it is still not enough to cope with the impact of large particle bed load in water conservancy projects,which limits its application scope in water conservancy projects.Steel fiber reinforced concrete has good mechanical properties such as fatigue resistance and impact resistance.In order to make full use of the good erosion resistance of rubber concrete and improve the impact resistance of rubber concrete by using steel fiber,making it better applied to various hydraulic drainage structures,this paper systematically studies the impact resistance of steel fiber reinforced rubber concrete.The main contents are as follows:(1)Through the compressive strength and split tensile strength tests of 72 cube specimens of 150mm×150mm×150mm,the influence of steel fiber content and rubber particle content on the compressive strength and split tensile strength of steel fiber reinforced rubber concrete was studied.The test results show that within the test range,the compressive strength and split tensile strength of steel fiber reinforced rubber concrete gradually increase with the increase of the amount of steel fiber,compared with rubber concrete with the same rubber content,the maximum increase of compressive strength and splitting tensile strength is 20.1% and 57.1%,respectively;the compressive strength and split tensile strength of steel fiber rubber concrete gradually decrease with the increase of the amount of rubber particles,compared with steel fiber reinforced concrete with the same steel fiber content,the maximum reduction of compressive strength and splitting tensile strength are 38.8% and 31.1%,respectively.(2)Through the drop hammer impact test of 36 trabecular specimens of150mm×150mm×550mm,the impact load,acceleration and strain time history of the specimens were measured,the equivalent bending load-deflection curve of the steel fiber reinforced rubber concrete specimen was obtained by calculation analysis,and the influence of steel fiber reinforced content and rubber particle content on impact resistance of steel fiber reinforced rubber concrete were researched with the energy absorbed per unit area at the section of the specimen being used as the impact toughness to characterize the impact resistance of concrete.The results showed that: steel fiber and rubber particles have a positive synergistic effect in improving the impact resistance of concrete,and steel fiber plays a major role in improving the impact resistance of concrete;When the content of steel fiber is between 0% and 1.25%,the impact toughness of steel fiber reinforced rubber concrete increases with the increase of the content of steel fiber,compared with rubber concrete with the same amount of rubber,the maximum increase is 813%;When the steel fiber content is between 1.25%and 1.75%,the impact toughness of steel fiber reinforced rubber concrete will decrease with the increase of the steel fiber content,but still higher than the impact toughness of the benchmark concrete;When the amount of steel fiber is the same,the impact toughness of steel fiber reinforced rubber concrete tends to increase gradually with the increase of the amount of rubber particles,compared with steel fiber reinforced concrete with the same steel fiber content,the maximum increase is 30.7%.(3)By statistically analyzing the distribution of steel fibers at the fracture surface of the specimen after the impact test,the influence of the number of steel fibers and the uniformity of fiber distribution on the impact resistance of steel fiber rubber concrete was studied.The test results show that: the improvement of the impact resistance of concrete by steel fiber is closely related to the number of steel fiber and the distribution uniformity of steel fiber at the section;with the increase of the number of steel fibers at the section,the improvement of the impact toughness of steel fiber reinforced rubber concrete firstly increases and then decreases;with the improvement of the uniformity of steel fiber distribution,the impact toughness of steel fiber rubber concrete shows a linear increase trend.