Study On Silica Fume For Modified Asphalt By Indoor Experiment

Adding various additives for asphalt material modification to improve the pavement performance of asphalt materials is one of the effective ways to meet the needs of the development of transport and improve the service quality of asphalt pavement. Based on the current application progress of inorganic material modifiers, this paper takes the silica fume as a modifier for asphalt modification. Through indoor experiment research, the paper analyzes and evaluates pavement performance of silica fume-modified asphalt,and also discusses the mechanism of silica fume modification. The study results of the paper lay a theoretical foundation for the application of silica fume in asphalt pavement.Based on the research progress of modified asphalt in China and abroad, plenty of experiments are carried out in combination with theory analysis in this article. First, through the performance tests of modified asphalt with the different content of silica fume including penetration, softening point, ductility, and elastic recovery, the paper processes the contradistinctive analysis about penetration index, T800,T1.2 ,etc, and studies the influence of asphalt's performance at high temperature and low temperature, the temperature susceptibility and elastic recovery capabilities by silica fume. On the basis of research of modified asphalt, Marshall mix design is carried out with modified asphalt with the different content of silica fume. This paper carries Marshall test and other kinds of pavement performance tests under the optimum asphalt content, summarizes the change law of Marshall and pavement performance indicators of asphalt mixture with the different content of silica fume, puts forward the appropriate content of silica fume, and provides a reference for Marshall mix design. At the same time the paper analyzes modification mechanism of silica fume from the compatibility. Silica fume has the property which makes it easy to be compatible with asphalt and achieves asphalt modification because of its adsorption function and toughening effect. Finally, the paper illuminates obvious social and economic benefits and biggish application value of silica fume-modified asphalt pavement by technical and economic analysis of silica fume-modified asphalt compared with ordinary asphalt and other modified asphalt.