Experimental Study On Road Performance Of Ceramic Fiber Asphalt Mixture

The use of fiber to enhance the performance of asphalt mixtures has become a common method.A large number of studies have shown that the addition of fibers can improve the mechanical properties and fatigue resistance of asphalt mixtures,which is an effective solution to reduce road damage and extend the service life of road surfaces.At present,there have been many studies on the performance and reinforcement mechanism of fiber asphalt mixtures such as basalt fiber,polyester fiber and glass fiber.Ceramic fiber has potential advantages in improving the road performance of asphalt mixture.Therefore,the main research content of this article is the influence of ceramic fiber on the road performance of asphalt mixture.In this paper,three types of ceramic fibers are studied: NC1260 spinning fiber(CF-A),NC1260 blowing fiber(CF-B)and NC1430 spinning fiber(CF-C).First,the microscopic morphology of the fiber was observed by SEM scanning electron microscopy.It was found that the surface of the ceramic fiber was smooth,the diameter was small,and the specific surface area was large.The spinning fiber was thicker than the blowing fiber and had better toughness.Then the test was designed to analyze the moisture absorption and heat resistance of different road fibers,and it was found that the ceramic fibers have good heat resistance and moisture absorption,so the ceramic fibers may become road fibers.The mixing process of the fiber asphalt mixture was studied through four mixing methods,and it was found that the dry mixing method and pre-mixing can ensure that the fibers are evenly distributed in the mixture.That is,the fibers are first dispersed into small pieces and fully mixed with the aggregate,so that a large amount of fine aggregate is adsorbed on the surface of the fiber,and finally mixed with asphalt.When the fiber content is 0.3wt%,the optimal oil-rock ratio of the three ceramic fiber asphalt mixtures is determined by Marshall test.Then the rutting test are mainly used to evaluate the high temperature performance of the asphalt mixture;the low temperature beam bending test and indirect tensile test are used to evaluate the low temperature performance of the asphalt mixture;The water immersion Marshall test and freeze-thaw split test are used to evaluate the water stability of asphalt mixtures.It is concluded that the incorporation of ceramic fibers can significantly improve the road performance of asphalt mixtures.The effects of CF-A and CF-C on the mechanical properties and road performance of the mixture are basically the same and higher than those of CF-B.The principle of fiber-reinforced asphalt mixture is analyzed from the macro and micro aspects through mobile phone camera and scanning electron microscope(SEM).The fiber's adsorption effect on asphalt mortar and the reinforcement effect in the mixture are analyzed.It can be observed that the fiber and asphalt have good wettability and good dispersion of the fiber in the mixture.It can be seen from the cross section after cleavage failure that the fiber is pulled out of the mixture,and there is a large number of fibers exposed in the sample cross section in the air,indicating that the fiber has sufficient tensile strength as an additive for asphalt mixture.Finally,the economics of fiber asphalt mixtures are analyzed.The cost of CF-A asphalt mixtures is increased by about 4.4% /t.Compared with other fibers,it is an inexpensive road fiber.The research results show that ceramic fibers can significantly improve the high-temperature performance,low-temperature performance,water stability,indirect tensile strength and other indicators of asphalt mixture,and improve the road performance of asphalt mixture.It is recommended to use NC1260 spinning fiber as the additive fiber of the mixture.