Research On Performance Of Unbound Ganular Flexible Base

Because of fine strength and fatigue resistence,semi-rigid base asphalt pavements are widely used in paement structures of heavy-traffic road in our country and overseas.lots of cases show crack is the main disease of semi-rigid base asphalt pavement and the cause of early occurrence of diseases of asphalt pavements of highways.After graded broken stone is provided weth excellent drainage,dispelling reflection cracking function and fine economics understand ,flexible pavement structure weth graded broken stone base will become an important structure of high-graded road pavement which is diversification developing in the future. Base on that ,relying on paper entities yunnan Kun'AN expressway project, paper research the pavement performance of graded broken stone.First of all,Paper analyses and inquirys the datas of asphalt pavements with graded broken stone base,and,combining with the theory of elasticity layered system,analyzing and calculating the stress distribution of graded broken stone layer in various pavement structure,various loading and various factors,and,sets the stress level 0f repeated loading in the lab base on the calculating result and simulates the loading status of graded broken stone layer in practice pavement.Secondly,paper analyses the factors of affecting graded broken stone base and permanent deformation,considering real condition,make repeated loading tests on graded broken stone mixs with three kinds Aggregate gradation in different stress level and different phycial state.In the same time,analyses the graded broken stone,Spermanent deformation and resilient modulus'affecting factors.Also,combining with test data and preveient research,draw out the permanent deformation,S estimating model.Making use of ANSYS software,and analysing the stress and strain on the testing road'S graded broken stone layer in normal,high temperature and overloading condition,combining lab's research on permanent deformation of graded broken stone inthe chapter3,and drawing the conclusion the possibility flexible pavement structure in testing road appering excessive plastic deformation is small.Finally , comparing the test road's practice measure data with theses ,obtainingresilient modulus's variety characteristic and affecting factors on graded broken stone。hich is used in base and sub base,and Introducln~constructin~technics and the request of quality control.