Research On Durability Of Asphalt Mixture Based On Epoxy

Durable pavement has the characteristics of long service life,small pavement damage,low maintenance cost,and economic total cost in the life cycle.Using epoxy asphalt mixture as pavement surface is a feasible way to realize pavement durability.Epoxy asphalt uses the thermosetting properties of epoxy resin and curing agent to give it excellent properties such as high strength,good high temperature stability and fatigue resistance.In this study,epoxy asphalt mixture is used as the pavement material of pavement surface.By adjusting the component ratio and mixture ratio of epoxy asphalt,the amount of epoxy component in epoxy asphalt is reduced,the durability of low content epoxy asphalt mixture is analyzed,and three kinds of epoxy asphalt pavement with excellent performance and economy are designed through mechanical calculation,so as to provide some reference and guidance for popularizing the application of epoxy asphalt durability pavement.Firstly,four AC gradations are optimized based on the theory of Bailey method.The optimal design density is determined to be 100%.Based on the optimal mineral aggregate gradation,the effects of different asphalt dosage,different lithology and different grade of aggregate on the Marshall strength of epoxy asphalt mixture were investigated.The results show that the compactness of the skeleton structure and the curing reaction of epoxy are the main factors affecting the strength of epoxy asphalt mixture.When the amount of asphalt in epoxy asphalt is higher than 75%,the curing effect of epoxy component is poor,and the epoxy component no longer plays a significant role in promoting the strength of the mixture;The difference of aggregate lithology and particle size has no obvious effect on the strength of epoxy asphalt mixture.Secondly,carry out the research on the road performance of epoxy asphalt mixture with different asphalt dosage,and explore its performance degradation degree under extreme conditions.The results show that epoxy asphalt mixture has excellent high-temperature performance,low-temperature performance and water stability.Epoxy asphalt mixture in the range of 60%-70% asphalt dosage still has better road performance under extreme conditions,can resist the adverse effects of extreme climate and meet the requirements of durability.When the asphalt content exceeds 70%,the performance advantage of epoxy asphalt mixture is not obvious.Considering the cost and performance,it is not recommended to use it in the actual road paving materials.Thirdly,the fatigue test of epoxy asphalt mixture with different asphalt content is carried out,and the fatigue performance of epoxy asphalt mixture is evaluated based on phenomenon method and dissipative energy method.The results show that the fatigue life of epoxy asphalt mixture with 60%,70% and 80% asphalt content is 4.27 times,2.91 times and 2.12 times that of SBS modified asphalt mixture respectively.The epoxy component can significantly improve the fatigue resistance of the mixture and meet the requirements of durability.Epoxy asphalt mixture with 60% and 70% asphalt content as pavement material has the potential to realize pavement durability.Finally,the mechanical parameters of epoxy asphalt mixture are obtained based on compressive resilience modulus test and stress relaxation test,and the structural mechanical analysis and combined optimization design of epoxy asphalt pavement are carried out by finite element simulation.The results show that compared with other structural combinations,the three epoxy asphalt pavement structural combinations of combination 3(4cm 60% EAC-13 + 4cm AC-13),combination 5(4cm 70%EAC-13 + 4cm 70% EAC-13)and combination 7(4cm AC-13 + 4cm 60% EAC-13)have better mechanical calculation indexes and economy.