Research On Crack Resistance Of Asphalt Rubber Mixture Surface

Crack is one of the main diseases of asphalt pavement and also the difficulty of road maintenance management. The main advantage of rubber asphalt is its superior anti-cracking performance. Based on the highway maintenance project and the mechanical analysis and experimental research, this paper exlored the characteristics of pavement crack mechanics, the design method of rubber asphalt mixture ratio. It analyse the types of asphalt, aggregate gradation, the influence of asphalt surface layer anti crack performance by adding fiber and other factors. This paper put forward the measures which can improve the crack resistance of asphalt pavement.The main contents of this paper:(1) the structural mechanics analysis of asphalt pavement with cracks, stress and strain variation analysis of the pavement structure with cracks. (2) The proposed rubber asphalt technology index system, compared with the performance of SBS modified asphalt and asphalt. (3) The mix design of rubber asphalt mixture. selected two kinds of gradation of intensive AC-13 and discontinuous SMA-13. (4) The performance of rubber asphalt mixture. study water stability and compressive modulus of rubber asphalt mixture experimentally. (5) The test research of low temperature crack resistance of rubber asphalt mixture. Compare the anti-cracking performance of asphalt mixture fibers with different asphalt types, gradation and fiber respectively. Put forward the technical measures of improving asphalt pavement crack resistance.The main conclusions of the study:(1) The shear stress and tensile stress are the main reasons of the asphalt layer cracks. The cracks are in the grassroots level. considering the heavy load, the shear stress and maximum principal tensile stress bith increase about 38%. So for the maintenance project, should enhance the crack resistance of surface layer material when the the grassroots have cracks. (2) The anti-cracking performance of discontinuous SMA-13 asphalt rubber mixture is better than intensive AC-13 rubber asphalt mixture, the critical strain energy density is 79.71%. (3) The residual stability of rubber asphalt mixture is 7.08% higher than SBS modified asphalt. The rebound modulus of SMA-13 rubber asphalt mixture is 1200-1800MPa of 20 degree. modulus after adding polyester fiber improves 6.19%;(4) the asphalt mixture is better than the modified asphalt and asphalt mixture. (5) The anti crack performance of the asphalt mixture increased 29.03% and 16.13% by adding polyester fiber and basalt fiber. The polyester fiber is better than basalt fiber. (6) Use the critical strain energy density as the index of rubber asphalt mixture crack resistance.