Experimental Study On Performance Of High Modulus Asphalt Mixture With Basalt Fiber

As one of the most common pavement disease, rutting has been a serious problem of highway. In order to solve this problem, many solutions are put forward by many scholars. High modulus asphalt mixture is a new type of road material, and it has a good performance in reducing rutting disease, while the fatigue performance remains to be further strengthened.Basalt fiber is a new type mineral fiber emerging in recent years. It can not only avoid the shortcomings of traditional fiber, but also improve the road performance of asphalt mixture effectively, especially the fatigue resistance,. Therefore, basalt fiber is attracting more and more attention in the road engineering. It has a great significance to the popularization and application of both basalt fiber and high modulus asphalt mixture, when combining the advantages of them.In this study, AC-20C gradation was selected for asphalt mixture composition design. Matrix asphalt, SBS modified asphalt, single basalt fiber, high modulus of asphalt mixture and basalt fiber high modulus asphalt mixture were contrasted by experiments. The optimum bitumen aggregate ratio of each asphalt mixture was determined by Marshall design method, and Marshall indexes of mixtures were analyzed. The results showed that basalt fiber could improve the stability of the high modulus asphalt mixture and reduce the flow value. Besides, dynamic modulus test was adopted to confirm the influence of basalt fiber to the mixture dynamic modulus. It turned out that after adding basalt fiber, the modulus of high modulus asphalt mixture decreased, however, it still could reach 10000MPa and meet the requirements of high modulus.Five kinds of asphalt mixtures were prepared under the optimum proportions. The rutting test, low-temperature trabecular bending test, immersion Marshall and freeze-thaw splitting test and four-point trabecular bending fatigue test were conducted to study the road performance contrastively, including high temperature stability, low temperature crack resistance, water stability and anti-fatigue performance. Experimental results showed that basalt fiber could further improve the anti-rutting performance of high modulus asphalt mixture, delay the attenuation at high temperature and ameliorate low temperature performance. After adding the basalt fiber, anti-fatigue performance of the high modulus asphalt mixture, which was urgently improved, increased obviously. Under the condition of 800 micro strains, fatigue life of mixture with basalt fiber was 1.7times of that without fiber.On the basis of the study in mixture performance, the pavement structure, which the high modulus asphalt mixture middle surface layer adopted, was optimized. Through the calculation of HPDS design software, the thickness of basalt fiber high modulus of asphalt mixture could be thinned to 4.3 cm from 6 cm. Moreover, the statics analysis was carried out on the pavement structure by ABAQUS software. Bottom tensile stress calculation indicated that adopting high modulus mixture to thin the thickness of middle surface layer would cause the change of stress state on this layer, and the surface material should need to own good anti-fatigue performance in big stress conditions, the basalt fiber high modulus asphalt mixture possessed good applicability. Similarly, vertical deformation analysis showed that high modulus asphalt mixture with basalt fiber in middle surface layer had better ability to resist rutting. According to the construction technical specifications, the thickness of the surface layer of the high modulus asphalt mixture with basalt fiber was finally determined as 5cm.Economic benefit, environmental benefit and social benefit of high modulus asphalt mixture with basalt fiber were made a comprehensive analysis and evaluation. It turned out that though high modulus asphalt mixture middle surface layer using basalt fiber would increase construction cost, maintenance costs could be greatly reduced in the pavement service life, so it had outstanding economic benefits. On the other hand, basalt fiber is a kind of inorganic mineral fiber, and its production and use process will not do harm to the environment. As a result, basalt fiber high modulus asphalt mixture could ensure the comfort of people’s travel and own good social efficiency.The research results of this paper provide a reference for the popularization and application of basalt fiber and high modulus asphalt mixture and have certain research significance and application value.