Performance of SBS/Crumb Rubber Composite Modified Asphalt

Modified asphalt (SBS/CRMA)was prepared using AH-70 as the basic asphalt and adding styrene-butadiene-styrene block copolymer(SBS)pre-swelled by furfural extract oil and crumb rubber.Effects of the amount of furfural extract oil and crumb rubber,stirring temperature and stirring time on the properties of modified asphalt were investigated through orthogonal experiment.Dynamic shear rheometer(DSR)was used to analyze the rheological properties of SBS/crumb rubber composite modified asphalt(SBS/CRMA),SBS modified asphalt(SBSMA)and crumb rubber modified asphalt(CRMA).Fluorescence microscope was used to observe the microstructure of SBS/CRMA.The results showed that SBS/CRMA has 5 ℃ ductility of 327 mm,softening point of 78.0 ℃,and elastic recovery of 91.6% under the optimized preparation conditions of furfural extract oil of 8%(mass fraction),crumb rubber amount of 25%(mass fraction),stirring temperature of 210 ℃ and stirring time of 2.5 h.SBS/CRMA is more flexible at low temperature and harder at high temperature,and shows better temperature susceptibility and better rutting resistance.Combining the fluorescence microscope graph of SBS/CRMA,a model of three-dimensional network structure was proposed.