Study On Geometric Characteristics And Structure Of Asphalt Mixture Aggregate

Geometric characteristics play a important role to performance of Asphalt Mixture, the shape of aggregate and its configuration in asphalt mixture such as Skeleton performance and filling characteristics all have strong impact to performance of asphalt mixture. For the reason of the aggregate which was used in asphalt pavement of highway is gathered from different field ,the quality of aggregate is ropy wholly. And for the other reason which the manager is lack of attention to geometric characteristics of aggregate, some new pavement were damaged in early time. So, it is very important to research the geometric characteristics of aggregate for asphalt mixture.The coarse asphalt mixture and SMA have more sensitivity than fine asphalt mixture; the content of flat and elongated particles should be less than 13%; for SMA , it should be less than 10%. The FAA of fine aggregate has strong relativity with performance of asphalt mixture and it can be used in evaluate angularity of fine aggregate. The FAA of fine aggregate should be less than 45%; we should not use natural sand which its FAA less than 40%, we should use sand less than 10%which its FAA less than 45%.The structure of aggregate play a important role to performance of Asphalt Mixture. Sustensation of skeleton has strong impact to high-temperature performance of asphalt mixture. The study takes DSI to evaluate skeleton performance asphalt mixture firstly. According to relative and regressive analysis ,the most sensitive factor is 4.75-9.5mm aggregate, the other is 16—19mm,13.2—16mm aggregate , the 9.5—13.2mm aggregate is the most in sensitive factor. According to different DSI, we partition the strong,ordinary,feeble area of asphalt mixture.The filling performance play a important role to lasting-performance of Asphalt Mixture. The study takes filling sensitive index of fine aggregate RRV firstly. The RRV not only reflect filling sensitive performance, but also reflect intervening sensitive performance. The intervening sensitive size is: 1.18mm,0.6mm, the filling sensitive size is : 0.3mm; the filling sensitive size of fine aggregate has strong relativity with performance of asphalt mixture.