Research On Mechanical Dynamic Response Law Of Rubber Concrete Pavement Structure Based On Model Test

Rubber concrete is better than ordinary concrete in terms of durability,fatigue performance,and dynamic performance.It is an ideal material for pavement structure and has been gradually applied in highway engineering.At present,the research on rubber concrete mainly focuses on the mechanical properties of rubber concrete,and there is little research on rubber concrete pavement structure.This paper studies the static and dynamic performance of rubber concrete pavement through model tests,and provides experimental and theoretical basis for rubber concrete to be widely used in road engineering.The main research work of this paper is as follows:Based on the theory of elastic thin plates,using the reciprocal theorem of work,the deflection of rubber concrete pavement with different content under static load is solved,and the formula for calculating the deflection of rubber concrete pavement under different content is obtained.Through model tests,the effects of different rubber content,vehicle weight and support stiffness on road deflection under static load are measured.The results show that the greater the rubber content,the greater the road deflection.The road deflection is directly proportional to the vehicle weight,and the road deflection varies with the vehicle weight.The increase in support stiffness decreases.The feasibility of using uniformly distributed spring-supported roads to simulate continuous-supported roads is verified.Through model tests,determine the vertical displacement of rubber concrete pavement and ordinary concrete pavement under different rubber content,vehicle speed,vehicle weight,dynamic load form and support stiffness,collect vibration signals,analyze road acceleration response,and study two road surfaces The difference in dynamic response under moving loads reveals the influence of factors such as vehicle speed,vehicle weight and rubber content on the dynamic response of the road surface.The test results show that an appropriate increase in the amount of rubber can reduce the amplitude of the road’s natural frequency.Vehicle weight,dynamic load form,rubber content and support stiffness have little effect on the first main frequency band of the amplitude spectrum;the amplitude of the first main frequency band of the amplitude spectrum increases with the increase of vehicle weight.The faster the vehicle speed,the amplitude The greater the increase,the greater the impact of different dynamic load forms on the amplitude of the40-60 Hz frequency band,the different rubber content has a certain impact on the peak frequency of the first main frequency band;as the rubber content increases,the second main frequency band The frequency range and peak frequency of the frequency range move forward,and the amplitude of the first main frequency band of the spectrum first increases and then decreases;with the increase of the support stiffness,the second-order frequency of the road model decreases slightly.The peak deflection of the road model mid-span increases approximately linearly with the vehicle model loading weight;the road mid-span deflection increases slightly with the increase of the vehicle model driving speed;the road mid-span deflection under normal dynamic load and the road mid-span deflection under static load The difference between the two tends to increase non-linearly;with the increase of the rubber content,the increase in the deflection of the pavement mid-span tends to increase non-linearly;the greater the support stiffness,the smaller the deflection of the concrete pavement mid-span.The ABAQUS finite element model is established based on the model test to analyze the dynamic response of the pavement under different rubber content and different vehicle weights.The test results are compared with the deflection curve of the pavement calculated by the finite element model to verify the dynamics of the pavement under the moving load.The feasibility of responding to the test.The results show that the simulated pavement mid-span deflection varies with the amount of rubber and vehicle weight in accordance with the test results.With the increase of the support stiffness,the maximum deflection of the pavement gradually decreases,and the decrease gradually decreases.Adding a certain amount of rubber powder can effectively reduce the maximum stress at the bottom of the rubber concrete pavement slab.