Study On Evaluation Index And Performance Of Framework Dense Structure Asphalt Mixture

Compared with ordinary AC asphalt mixture, durable dense skeleton type asphalt mixture had excellent gradation which coarse aggregate could fully play a frame role and fine aggregate could fully play a filling role. Due to this, it would be the main development trend of current mixture design. Meanwhile,by enhancing the stability of asphalt mixture, durable dense skeleton type asphalt mixture dramatically improved the pavement performance and mechanical performance. And more importantly, this gradation had a vital practical significance to reduce the disease of asphalt pavement and extend the service life.The research was aim to propose a new optimum design method about durable dense skeleton type asphalt mixture. At first, by doing tests on road performance and mechanical performance, the paper studied the connection between t through rate of the key sieve pore and performance of mixture and proposed a recommended value about the passing rate of key screen openings which could form a durable dense skeleton structure.Secondly, using gray correlation analysis method, the primary evaluation index of dense framework structure and the index of road performance and mechanical performance about mixture were analyzed. According to compare these indexes, a optimal evaluation index was selected. On the basis of above research, the paper proposed an optimization design method based on the durability of mixture. Finally, industrial waste was added in this mixture and the paper analyzed the influence of the additive on pavement performance 、 mechanical performance and durability of mixture.The results above shows that the through rate of sieve pore of 4.75 mm and the dosage of 2.36~4.75 mm coarse aggregate have a significant influences on pavement performance and mechanical performance of mixture during the gradation design process. It was found that when the through rate of sieve pore of 4.75 mm was about 35% and the dosage of coarse aggregate at 2.36 mm ~ 4.75 mm diameter was controlled at 0%~5%, the mixture could form a dense framework structure. It was suggested that density of structure C was a suitable index and the recommended value was 1.06 to 1.10. Industrial waste could not only improve the pavement performance and mechanical performance of mixture, but also improved the durability.