Based On Uniaxial Penetration Test Study Of Equilibrium Design Method Of Recycled Asphalt Mixture

With the continuous development of asphalt pavement recycling technology,more and more waste asphalt mixture is recycled to the pavement,which is in line with China's sustainable development strategy.However,the durability of recycled asphalt mixture has not been well solved.Therefore,it is an urgent task to quickly evaluate the durability and reliability of recycled asphalt mixture and to design the mixture ratio of recycled asphalt mixture based on its road performance.Firstly,the stress models of semi-circular bending test and uniaxial penetration test are analyzed,and it is found that the crack model of uniaxial penetration test is more in line with the actual pavement crack situation.according to semi-circular bending test,a new evaluation method and index di of recycled asphalt mixture crack resistance based on uniaxial penetration test are proposed.Then the high temperature resistance of recycled asphalt mixture with different rap content was obtained by 60 ? uniaxial penetration test,and the crack resistance of recycled asphalt mixture with different rap content was obtained by 25 ? uniaxial penetration test.Finally,through the analysis of these laws,the contradiction between high temperature resistance and crack resistance of recycled asphalt mixture is balanced,and the middle value of rap content which meets both high temperature resistance and crack resistance is taken as the optimal content.The experimental result show that that penetration index di of the recycled asphalt mixture base on the uniaxial penetration test has a good linear correlation with the flexibility index fi,and can accurately reflect the anti-cracking performance of the recycled asphalt mixture.The optimum rap content is determined by the equilibrium design method of recycledasphalt mixture based on uniaxial penetration test,and the pavement performance of the mixture meets the construction technical specification.