Study On The Performance And Optimization Design Of Epoxy Asphalt Ultra-thin Cover

Ulter-thin cover technology is an important method applied to preventive maintenance in early stage,which can effectively reduce the risk of road surface disease and the cost of maintenance,thus improving the life of road surface.Currently,there is a lot of research on ulter-thin cover technology,but there are relatively few studies on the gradation optimization design directly based on the functional requirements of ultra-thin cover.Therefore,based on the existing ultra-thin cover technology,the gradation optimization design and road performance verification of antiskid epoxy asphalt ulter-thin cover are studied in depth through indoor testing and simulation,thus proposing an ultra-thin cover technology with excellent antiskid performance and durability.Firstly,gradually filling test and gradually crushing test are used to determine the boundary between the coarse and fine sieves with ulter-thin cover gradation and the role of each particle size aggregate.Then viscosity-temperature characteristics and viscosity-time characteristics of N-11 epoxy asphalt are determined by rotational viscosity test and tensile test,thus obtaining mixing temperature and curing conditions of epoxy asphalt mixture.In addition,the relationship between powder-binder ratio and low temperature performance is determined by bending beam rheological test of epoxy asphalt mortar.Secondly,the mesoscopic model of ultra-thin cover based on rigid body dynamics and impulse collision theory is used to optimize the gradation design.Then combined with image processing technology,the pore distribution characteristics characterizing the anti-skid performance are extracted.By quantifying the pore distribution characteristics of AC-5,SMA-5,OGFC-5 and Novachip Type-A,the intrinsic relationship between grade and pore distribution is established.Based on this,three control parameters reflecting the gradation characteristics and influencing the po distribution characteristics are proposed: the ratio of coarse sieve aggregate dosage,the ratio of fine sieve aggregate dosage and the ratio of coarse and fine aggregate dosage,and then the optimal gradation of anti-skidding ultra-thin cover is determined.The gradation has the characteristics of rich surface pore structure,dense internal structure and moderate bottom pore volume.Then,actual pore distribution characteristics of anti-sliding epoxy asphalt ultra-thin cover are verified based on CT scanning and 3D reconstruction technology.In addition,anti-sliding durability test,low-temperature beam test and bending fatigue test are used to study the antisliding performance,low-temperature performance and durability of epoxy asphalt ulter-thin cover.Compared with SMA-5 ultra-thin cover,the low-temperature crack resistance of epoxy asphalt ultra-thin cover is relatively poor,but the dirrerence between the two is small,and the anti-sliding performance and durability are significantly better,which meet the design requirements.Finally,based on the common failure modes of ultra-thin cover and adhesive layer,the concept of gap-filling adhesive layer and interlayer adhesive layer is proposed.The total amount of epoxy asphalt adhesive layer is determined by extraction of effective pores in the mesoscopic model,shear test and pull-out test at different temperatures.In conclusion,the optimized design scheme of epoxy asphalt ultra-thin cover proposed can meet the maintenance goal of pavement with anti-sliding demand.The research results are helpful for the popularization and application of anti-sliding ultra-thin overlay technology.