Gradation Design and Performance of Fiber Reinforced Semi-Open Graded Asphalt Treated Base

Abstract

To enhance the durability of semi-rigid base asphalt pavement, it is suggested that the asphalt treated base (ATB) layer should have certain drainage capacity and improved crack resistance to reduce the occurrence of moisture damage and to prevent generation and propagation of reflection crack. The optimal objectives were put forward, namely, its porosity can be controlled at 8% to 12%, coarse aggregates should form a stable skeleton, and the intermediate particle size coarse aggregate can be completely or partially gapped, fine aggregate content should be increased to enhance adhesion between coarse aggregates, and lignin fiber can be added to increase the content of asphalt binder and enhance its crack resistance and durability. According to these objectives, the gradation optimal processes were put forward, and lignin fiber reinforced semi-open grade ATB mixture, FATB, was optimized. Then, the seepage capacity, rutting resistance and anti-reflective crack capacity were tested and compared with those of AC -25 and ATB-25. The results indicated that drainage capacity of the optimized FATB-25 meets the requirements, and its performances were significantly better than those of the contrast mixtures, AC-25 and ATB-25.