Research On Damage Mechanism Of Ordinary Cement Concrete Pavement Under Heavy-duty Vehicles

With the advantages of low cost,easy access,high temperature resistance,high stiffness,strong bearing capacity and low maintenance cost,cement concrete has developed rapidly in China,but the early damage of cement pavement is quite serious.At present,some domestic vehicles are overloaded and overloaded heavy-duty vehicles.When the wheel acts on the road surface,the internal stress,strain and direction of the cement concrete pavement structure are unknown.The pavement structure obtained by the conventional design method can not meet the requirements of the heavy-duty vehicles in the present environment.Therefore,it is necessary for the heavy-duty vehicles and the ordinary cement concrete pavement to act as a machine.We should conduct in-depth research.In this paper,the vertical acceleration value of vehicle axle is measured by the self-developed triaxial accelerator tester,and the dynamic load law of vehicle is analyzed.At the same time,a road structure model test method based on large MTS tester to simulate vehicle load is designed.The feasibility of MTS simulating vehicle load is determined by the design of MTS acting indenter and the relationship between acting load and grounding area and grounding pressure.Taking typical rigid pavement and semi-rigid base pavement structure as research objects,the mixture ratio test of pavement materials is carried out.According to the pavement structure model established,the pavement slab under heavy load of cement concrete pavement is carried out by using large-scale MTS equipment.Internal stress and strain response tests were carried out to obtain strain data at different loading locations under heavy loads.The variation law of internal stress of cement concrete pavement under heavy loads was given.A three-dimensional finite element model of cement concrete pavement was established by ABAQUS software and simulated.Based on the comprehensive analysis and comparison of the measured strain data and the three-dimensional finite element model,the general law of early damage of typical cement concrete pavement is given: dynamic load increases the role of vehicles on the pavement,and plays the role of increasing load in disguised phase.This effect is extremely great for the damage of cement pavement,and is the fundamental cause of the damage of cement pavement.