Study On Properties Of Basalt Fiber Reinforced Asphalt And Its Mixture Based On Surface Energy Theory

With the development of highway construction in China,the demand for high-performance asphalt pavement is increasing day by day.As an effective means of enhancing asphalt mixture,fiber incorporation has broad application prospect.Basalt fiber,as a kind of high performance green fiber,can greatly improve the road performance of asphalt mixture.However,due to its smooth surface and chemical inertia,basalt fiber has insufficient adsorption capacity for asphalt in the process of combining with asphalt,which affects the application effect of basalt fiber in asphalt pavement.To solve this problem,there have been more to the study of the surface modification of basalt fiber,basalt fiber mixed with asphalt modified test and performance variation of asphalt mixture,however,the method of surface modification for fiber limited to KH550 silane coupling agent modification,lack of different coupling agent modification on the properties of fibers and asphalt interface impact study,There is also lack of research on the correlation between interfacial properties and asphalt and asphalt mixture properties.Therefore,in this paper,seven silane coupling agents KH550,KH560,KH570,UP580,UP602,UP312 and A171 were selected to modify the bundle basalt fibers,and the surface characteristics of the bundle fibers before and after the modification were characterized by scanning electron microscopy,surface energy and Fourier transform infrared spectroscopy.Determination of modification of shaped basalt fiber reinforced beam before and after 70 # SBS modified asphalt cone into the degree,strength,ductility,softening point,study the silane coupling agent modification for beam of basalt fiber reinforced asphalt mixture of SMA and high temperature stability,low temperature crack resistance and water stability,the influence of the final through linear regression fitting and Pearson correlation analysis,The relationship between the adhesion between fiber and asphalt and the properties of fiber reinforced asphalt and asphalt mixture was analyzed.The purpose of this paper is to study the performance change characteristics of basalt fiber modified by different silane coupling agents on basalt fiber reinforced SBS modified 70# asphalt and SM-13 asphalt mixture,and to explore the internal mechanism and correlation of basalt fiber surface characteristics on the performance improvement of asphalt and asphalt mixture.After a large number of experimental studies,the main conclusions of this paper are as follows:(1)After modified by silane coupling agent,the surface roughness of basalt fiber is improved,which is conducive to enhancing the adhesion of the interface between the fiber and SBS modified asphalt;It was found by surface energy measurement that the surface energy decreased after the modification of silane coupling agent.By Fourier transform infrared spectroscopy(FTIR),it was found that the silane coupling agent formed a stronger Si-O-Si bond by chemical bonding with the hydroxyl group(-OH)on the surface of the fiber.By introducing its own characteristic functional groups,the surface activity of basalt fiber was improved.According to the calculation of adhesion energy,the modification of KH550 and UP580 can improve the adhesion energy between basalt fiber and SBS modified asphalt,while the modification of other coupling agents will reduce the adhesion energy,which is not good for the combination of basalt fiber and asphalt.(2)The low temperature tensile property and shear strength of SBS modified asphalt reinforced by basalt fiber KH550 and UP580 among 7 silane coupling agents are improved,while the other effects are not obvious.The effect of 7 silane coupling agents on the softening point of SBS modified basalt fiber reinforced asphalt is not obvious.(3)The optimum asphalt-stone ratio is 6.0% when the content of bundle basalt fiber in SM-13 asphalt mixture is 0.5%.The basalt fiber reinforced SMA-13 asphalt mixture modified by KH550 and UP580 has the best road performance.Compared with the unmodified bundle basalt fiber,the dynamic stability,failure strain,immersion stability,residual stability and freezing-thawing splitting ratio of the SBS modified 70# asphalt mixture enhanced KH550 improved by 5.4%,3.8%,2.1%,2.3%and 3.4% respectively.(4)After linear regression fitting and Pearson correlation analysis,it can be concluded that the adhesion energy between basalt fiber and asphalt has a very significant and strong correlation with various properties of basalt fiber reinforced asphalt and asphalt mixture,indicating that the performance change trend of asphalt and asphalt mixture can be predicted by adhesion energy calculation.To guide the implementation of surface modification technology of basalt fiber.