Experimental Study On Tensile And Impact Resistance Of High Fluidity Steel Fiber Rubber Concrete

The high brittleness of ordinary concrete limits its application in practical engineering.Rubber concrete made of rubber particles instead of some fine aggregates can realize the recycling of waste rubber and improve the brittleness of ordinary concrete,but it will reduce the strength of concrete.The incorporation of steel fiber into rubber concrete can improve the strength of rubber concrete.Considering the requirements of paving work on the working performance of concrete in actual road engineering,this paper designed 10 groups of high fluidity concrete with different mix ratios,and made 190 concrete test blocks.The effects of steel fiber content(0.8%,1.2%,1.6%)and rubber particle replacement rate(10%,15%,20%)on the performance indexes of concrete were studied.In this experiment,the mechanical properties of high fluidity steel fiber rubber concrete were studied.The main research results are as follows :(1)The fluidity of steel fiber reinforced rubber concrete is less than that of ordinary concrete.With the increase of rubber particle replacement rate,the slump of concrete increases by 5.3 %-7.5 %.With the increase of steel fiber content,the slump of concrete decreased by7 %-11 %.(2)Steel fiber can improve the compressive strength and splitting tensile strength of concrete.The incorporation of rubber particles reduces the compressive strength and splitting tensile strength of concrete.In the test range,the compressive strength and splitting tensile strength of concrete are the largest when the steel fiber content is 1.6 % and the rubber particle replacement rate is 10 %.The compressive strength and splitting tensile strength increased by14.3 % and 12.6 %,respectively.(3)The results of axial tensile test and bending test show that both steel fiber and rubber particles can improve the toughness of concrete,and the improvement effect of steel fiber is better than that of rubber particles.When the steel fiber content is 1.6 % and the rubber particle replacement rate is 10 %,the axial tensile strength and bending strength of concrete are the largest,which are increased by 31.79 % and 52 % respectively.The functional relationship between the axial tensile strength and flexural strength of concrete with the content of steel fiber and rubber particles was established and verified.(4)The impact resistance test results show that steel fiber and rubber particles can improve the impact resistance of concrete.When the steel fiber content is 1.6 % and the rubber particle replacement rate is 20 %,the impact resistance of concrete is the best.Through the statistical analysis of the impact test results,the impact resistance life of concrete is analyzed by the twoparameter Weibull distribution model,and the prediction results are in line with the actual situation.