Abstract: In order to prepare the applicable rubber powder modified asphalt used for asphalt pavement aiming at the influence factors such as the particle size of crumb rubber, the dosage of powder, shearing time, preparing temperature and shearing rate, the orthogonal test of 5 factors and 4 levels was applied in this paper, Meanwhile, elastic recovery rate, shear strength, segregation softening point difference and viscosity-temperature regression coefficient |B| were selected as evaluation indexes.Based on that, the optimal scheme of preparation of rubber powder modified asphalt was selected and the rubber modified asphalt was prepared well and its mechanism and road performance were analyzed.The results show that the asphalt modified with rubber powder under the condition of 30 mesh rubber powder with content of 24%, shear time of 60 min, preparation temperature of 205 ℃and shear rate of 5000 r/min has better performance.The porous powder particles uniformly dispersed in the asphalt system absorb the light components of asphalt, produces swelling and weak chemical reaction and presents the space network cross-linked structure, which is the main reason for the excellent performance of rubber powder modified asphalt.

Key words: road engineering;rubber powder modified asphalt;preparation technology;road performance;mechanism analysis