Fatigue Test And Life Prediction Of Pre-treated Rubber Concrete

The concrete made by treating the broken rubber tire particles to replace part of fine aggregate can not only reduce the consumption of natural resources,but also effectively utilize solid waste.Experiment on the basis of C30 concrete,with the particle size of 1 ~ 2mm,2 ~ 4 mm rubber particles pretreatment by 5% NaOH and 1% KH570 solution,afterwards replace the fine aggregate volume by 2.5%,5.0%,7.5%,and10%.Useing the rubber air content of concrete mixture,slump and concrete after hardening mechanics performance index,evaluation of rubber particles to improve the performance of the surface pretreatment of rubber concrete.The rubber concrete trabeculars which with rubber particle size of 1~2mm and pretreated by solution of 1%KH570 and substitute the fine aggregate volume by 2.5%,5.0%,7.5%,and10% were tested under three-point bending load and fatigue test under cyclic load.The main research results are as follows:(1)The mechanical properties of rubber concrete with particle size of 2~4mm are lower than those with particle size of 1~2mm.With the increase of rubber content,the 5%NaOH and 1% KH570 solution pretreatment of rubber concrete mechanics performance were showing a certain degree of increase,the silane coupling agent KH570 solution pretreatment effect is good,effectively restrain the rubber concrete mixture gas content and the growth of the slump,hindered the mechanical properties of rubber concrete is reduced,increased the strength of concrete after hardening.(2)Rubber concrete under static deflection of the plastic failure pattern,the strain value higher than that of ordinary concrete,under the condition of the rubber particles and the stress level must be,by KH570 1% solution pretreatment of rubber concrete beams under fatigue load of fatigue cycle is slightly higher than that of ordinary rubber concrete,the bad times KH570 coupling agent solution can improve the bonding effect of aggregate interface,full play to the elastic deformation of rubber,reduce the internal damage degree,improve the shock resistance and seismic performance of concrete.Under the action of fatigue load,concrete strain experienced three stages: the initial stage of damage,the stage of stable development and the stage of unstable development.(3)Using the weibull distribution and lognormal distribution for pretreatment of rubber fatigue life of concrete under different stress level test in the test results,calculation of fatigue life in different survival rate under different survival rates and set up the single and double logarithm fatigue equation of logarithmic fatigue equation,and according to the fatigue equation to calculate the fatigue strength of pretreatment of rubber powder.