Study On The Development Of Epoxy Polymer Concrete And Its Impact Fatigue Characteristics

With the rapid development of high grade highway construction in our country,tens of thousands of bridges are opened to traffic every year,but the premature destruction of bridge deck pavement is a problem to be solved urgently.Epoxy polymer concrete is a kind of high performance engineering materials,with short curing time,compressive strength and tensile properties,good chemical resistance and strong learning medium medium strong resistance etc.This material is expected to solve the premature failure of bridge deck pavement.In the process of operation,due to the uneven settlement of the bridge and highway,leading to the bridge "jump" phenomenon is more and more serious.Because of the temperature stress and the overweight vehicle load,cracks will occur in the bridge deck pavement,and there are different degrees of damage.The damage of the bridge deck pavement will be intensified when the vehicle is subjected to the load.The effects of material mix ratio and curing time on the quasistatic mechanical properties were studied.Based on the analysis of the jumping load,the impact fatigue test of the epoxy polymer concrete with initial damage was carried out.At the same time,body image of the species with initial damage is reconstructed with the 3D CT scanning technique.The distribution of internal cracks in the specimens was calculated.The effect of initial damage on the fatigue performance of epoxy polymer concrete was studied.The main contents of this paper include:(1)Selection of aggregate gradation of epoxy polymer concrete and the preparation technology are studied.The four point bending test and compression test of epoxy polymer concrete were carried out.The effects of the ratio of epoxy and aggregate,aggregate gradation and curing time on flexural strength,compressive strength and elastic modulus were investigated.(2)The theoretical analysis model of "jumping" phenomenon is established.The impact load of the truck wheel on the road surface is calculated.According to the calculation results,the drop hammer impact test parameters were determined,and the impact test of epoxy polymer concrete specimens was carried out.The impact force time history curve was obtained.The fatigue properties of epoxy polymer concrete under low impact energy were studied.The impact fatigue failure modes of epoxy polymer concrete under high impact energy were studied.(3)In order to simulate the damage in the pavement,the epoxy polymer concrete specimens with different degrees of initial damage were prepared by quasi-static cyclic compression.The 3D CT scanning is used to reconstruct the body image of the specimen.The relationship between the Percentage of crack volume and damage variable based on attenuation of elastic modulus of the material is established.The elastic modulus of the specimens subjected to drop hammer impact after a certain number of times was measured,and the variation of the impact damage of epoxy polymer concrete of different degrees of initial damage was analyzed.The influence of initial damage on the shock response and failure mode of epoxy polymer concrete in the process of impact fatigue was studied by attenuation of elastic modulus of epoxy polymer concrete under repeated impact load.(4)This paper explores and studies the field paving technology of epoxy polymer concrete,and puts forward some improvement measures.