Research On The Technology Of Alpine And High-Altitude Areas' Asphalt Layer Anti-cracking

At present,asphalt surface cracking is one of the main forms of early damage of high grade asphalt pavement,which seriously reduces the function and life of asphalt surface.Especially when the asphalt pavement in the harsh environment of the harsh environment,the asphalt surface of the early cracking problem is more severe.In this paper,the method of delaying the formation of early cracks in asphalt pavement was studied in the context of high temperature and high altitude in Wenchuan to Malkang Expressway.The main content of this paper is divided into the following points:(1).In this paper,we first study how to improve the service life of asphalt pavement in alpine high altitude climatic conditions by using high viscosity and high elasticity modified asphalt as the starting point.SBS modifier was used as the elastic group.At the same time,four kinds of viscosity-modifying agents such as SINTOPS,Duroflex,HVM-700 and terpene resin were used as the thickening group to prepare high viscosity and high elasticity asphalt.The viscoelastic properties of composite modified asphalt were evaluated by two factors,elastic recovery and dynamic viscosity at 60 ?.Comparison of viscoelastic properties between groups of high viscosity and high elasticity modified asphalt.(2).Because of the mechanical properties of modified asphalt can not fully reflect its road performance.Therefore,in order to study the road performance of the high viscosity and high elastic modified asphalt,the high viscosity and high elastic modified asphalt was prepared by RTFOT asphalt aging test and rheological shear test.The test results show that the aging performance of high viscosity and high elastic modified asphalt can meet the practical requirements of the road,and both the original asphalt and the PG grade of the aging asphalt are at a high level.(3).Based on those test,the modification mechanism of high viscosity and high elasticity asphalt was analyzed briefly from the angle of modification mechanism.It also provides some theoretical support for the preparation of the asphalt,and also makes the research on the optimization of the subsequent modifier and the selection of the modifier.(4).In this study,SMA-13 and AC-13 were used to compare the pavementperformance of two kinds of asphalt mixtures with different structural forms.The high and low temperature performance and water stability of the mixture were evaluated by high temperature rutting,trabecular bending,immersion Marshall and freeze-thaw cycles.Contrast with the above road performance test.In this paper,it can be concluded that when the modified asphalt elastomer is 6%SBS and the viscous component is blended with 4% SINTOPS with 3% HVM-700,the modified asphalt has better viscoelastic properties and Performance.The use of the asphalt for the preparation of SMA-13 type asphalt mixture can more effectively delay the early cracks in the asphalt surface under the climatic conditions in the alpine and high altitude area.