Study On The Grade And Performance Of Open-graded Friction Courses (OGFC)

Open graded friction courses (OGFC) is a kind of open graded porous asphalt mix designed to drain water on the road face when raining. It has good performance on draining, anti-slide and noise reducing. It is common used in foreign countries from 1980s, while the lack in China because its poor mechanics performance, due to the high pore rate, cannot fit for the heavy traffic load in China.The grade composite, road performance and its mechanism are systemically studied. 1) The aggregate grade of OGFC is studied through the volume method base on the analysis of the aggregate grades. Then the grade is verified and the relation between the grade and pore rate is studied statistically, the typical grades of OGFC are developed; 2) The reasonable pore rate of OGFC is studied on the basis of the balance of mechanics and function performance; 3) the mineral fiber is added to the OGFC mixes to increase asphalt content, thus the anti-water performance of OGFC mixes are improved; 4) high viscous asphalt fit for the preparation of OGFC is prepared through composite modification by SBS and rubber powder; 5) The mechanics mechanism of OGFC is studied in the paper, it shows: asphalt paste, as well as the coarse aggregate skeleton, is essential to the mechanics of OGFC.