Study On Properties And Mechanism Of Nano-organized Palygorskite And Its Compounded SBS Modified Asphalt

Palygorskite(Pal),one of the advantageous non-metallic minerals in China,is an inexpensive nano-silicate mineral material.It is widely used in various materials to reduce costs and improve properties due to its beter properties of physical and chemical and abundant reserves.Based on the extensive collection of domestic and foreign research results,the organic treatment of Pal was carried out based on the basic characteristics and structure of Pal,and A－Pal was prepared for improving all aspects of performance of asphalt as pavement materials in this paper.The high-temperature rheological properties,water damage resistance,anti-aging properties and storage stability of modified asphalt by A-Pal and modified asphalt by A-Pal compounded SBS and its changes of microscopic mechanism with the content of A-Pal were studied in depth by the method of macroscopic road performance and microscopic characterization and the combination with large numbers of experiment,and presented the recommended dosages of engineering,which provided a theoretical basis for the application of Pal modified asphalt in road asphalt.In the first,the experimental method of the organic modification of Pal was analyzed.The process of preparing the organic Pal by acid activation and then dealcoholization condensation was determined through the organic treatment of Pal by γ-aminopropyltriethoxysilane.The chemical and crystal structure of A-Pal were characterized by Fourier transform infrared spectroscopy and X-ray diffraction.Three indexes,DSR temperature scanning and fatigue.BBR,contact angle,TFOT and PAV tests,SEM and EDS micro tests were carried out on different dosages of modified asphalt by A-Pal.it was found that A-Pal in asphalt could not only exert the effect of "macromolecule chain" reinforcement of nano fibers,but also exert the effect of adsorption and shielding of general nanomineral modifiers,which could effectively improve the high temperature performance,water stability and anti-aging performance of matrix asphalt,the optimum dosages was 6wt%in high temperature and rainy areas,that was 4wt%in high temperature and lass rainy areasThen,the A-Pal combined with star SBS(YH-801)or linear SBS(YH-791)were used to modify the matrix asphalt in this paper.Three major indicators,temperature scanning,frequency scanning,medium temperature fatigue,BBR,contact angle,TFOT,PAV and multi-period segregation were carried out on the A-Pal complex wiring(YH-791)and star SBS(YH-801)modified asphalt.It was found that adding A-Pal could not only significantly improve the high temperature performance,water stability,anti-aging performance and storage stability of YH-791 modified asphalt,but also improved the high temperature performance,water stability,aging resistance,low temperature performance and fatigue properties of YH-801 modified asphalt combined with microscopic examination of fluorescence microscope.The effect of modification depends largely on the phase morphology of SBS modifier in matrix asphalt.The effect of A-Pal compound YH-791 modified asphalt with double continuous phase was better than that of compound YH-801 modified asphalt.In which the recommended dosage was 3 wt%.