Research On AC13 Mix Design On Skeleton Interlocking Dense Condition

With the rapid development of economy, highway enterprises have been in the golden time of development in our country in recent years. However, due to the key technical reserve inadequate, the damages of pavement become serious soon, especially rutting damage. Asphalt mixture with skeleton dense structure has won increasing reputations by pavement engineers because of its good high-temperature performance.Based on the previous researches at home and abroad, this paper is systematically explored the geometric characteristics of the coarse aggregate particles and the closest compact condition of the asphalt mixture with skeleton structure. It is deeply analyzed the influencing factors about the skeleton interlocking dense condition. It is considered that the important factors are the geometric characteristics and the gradation of the coarse aggregate particles as well as the compacting work. According to existing problem that gradation design and the bitumen-aggregate ratio design are isolated,this paper is deeply studied its connection based on the design of AC13 mix by adjusting the gradations through adjusting the relative content of two kinds sizes of coarse aggregate particles and adjusting the content of coarse aggregates. From the explorations and researches, it is indicated that the bitumen-aggregate ratio in the closest compact formation condition is decreased first, then increased with coarse aggregate's content reducing. From studying on the change law, it can be obtained a catastrophe point at which the bitumen-aggregate ratio is optimal and the corresponding gradation is the optimal gradation. So the asphalt mix design can be gained. From the laboratory verification tests, the asphalt mixture designed has excellent mechanical properties and pavement performances. Besides, aiming at the controversy on the methods of maximum theoretical density in engineering application,this paper is discussed the measure method of the aggregate effective density and the gradation correction. It is explored appropriate calculate formulas and test methods from theoretical analysis and laboratory tests. Through the discussion and the research,it can provide a reference of asphalt mix design for asphalt pavement, which makes asphalt mixture has the excellent performances.