Study On The Properties And Interfacial Bonding Characteristics Of Basalt Fiber Asphalt Mastic

With the expansion of highway construction in China,a large number of road diseases occurred on asphalt pavements.Asphalt binder materials directly determine the durability and performances of asphalt pavements.In this study,basalt fiber(BF)was adopted to replace other kinds of fibers in the asphalt material because of its excellent performance.The use of BF for asphalt materials has broad prospects.Therefore,in order to reveal the mechanism of basalt fiber asphalt binders,a lot of research on the basalt fiber's morphological structure,basic properties,and the interfacial bonding properties between bitumen and asphalt,and the road performance of basalt fiber asphalt binders were studied.First of all,the properties of basalt fiber such as water absorption,high temperature resistance,pH value,asphalt adsorption capacity and microscopic morphology were measured.The results showed that among the three kinds of chopped basalt fibers,the B type BF was acidic,which was unfavorable to the adhesion of asphalt mixture interface.The moisture absorption rate and the high temperature loss of the C type BF were the highest,which was not conducive to the stability of the performance of the asphalt.And the A type BF has high modulus of elasticity,tensile strength,small water absorption and good high temperature stability.It helps to slow down the phenomenon of water damage on asphalt pavement and improves the softening and low temperature embrittlement of asphalt at high temperature.Secondly,the effects of powder-binder ratio,basalt fiber content,fiber type and aging conditions on the high and low temperature performance of asphalt mortar were tested by Dynamic Shear Rheological test(DSR)and Bending Beam Rheometer test(BBR).The results showed that the addition of ore powder was beneficial to improve the high temperature performance of asphalt mortar,but it was unfavorable for low temperature performance,and the ratio of powder and rubber should be between 0.8 and 1.2;Basalt fiber improved the high temperature stability performance and anti-aging performance of slurry,and the suitable blending ratio ranges is from 1%to 4%,and the best blending content is about 2%.But the addition of BF didn't contribute to the low temperature performance of asphalt mortar.After adding three kinds of chopped basalt fibers,the performance of A type BF asphalt mortar is the best,and the temperature sensitivity is lower.It is beneficial to improve the aging resistance and fatigue resistance of the slurry,and is more suitable for asphalt pavement.Thirdly,combining the characteristics of asphalt materials,the interface bonding strength between basalt fiber and asphalt materials was evaluated by a fiber asphalt drawing tester,and the main factors affecting the reinforcing effect of basalt fibers were studied.The data showed that the basalt fiber length of 20mm in the SBS modified asphalt to withstand the maximum interface force than the length of 6mm increased by 42.6%.Under the requirement of dispersibility,the closer the fiber length is to the critical length,the more fully the mechanical properties are exerted;the better the strength properties of the matrix material,the greater the bond strength between the interfaces.Finally,the surface energy between basalt fiber and solid asphalt were carried out,and the adhesion work at the interface is analyzed.At the same time,the microstructure of the representative surface and some damage surface of the basalt fiber asphalt was observed by using the Scanning Electron Microscope(SEM).It showed that the surface energy of SBS modified asphalt was higher than that of matrix asphalt,and its adhesion to fiber was better.As a cement material of basalt fiber,it can form a strong interfacial adhesion.A type basalt fiber has good adhesion to asphalt and can effectively reduce the temperature sensitivity of asphalt and improve the high temperature stability of asphalt mixture.The research results provide references for the types and technical requirements of basalt fiber used in asphalt pavement engineering,and have certain theoretical research significance and engineering application value.