With The Design Method Based On Three Decentralized System Of Asphalt Mixture

Mortar theory assumes that asphalt mixture is a dispersed system of multilevel interspace reticulate structure. The mix is a coarse dispersed system with the dispersed phase of coarse aggregates dispersing in the medium of asphalt mortar; the mortar is a fine system with fine aggregates dispersing in filler bitumen; filler bitumen is a tiny system with fillers dispersing in asphalt. On the basis of three-level dispersed system of asphalt mixture, this paper defines AM as the ratio of asphalt mortar volume to coarse aggregate void volume and AP as the ratio of filler bitumen volume to fine aggregate void volume. Based on AM and AP, the paper studies mix design method of asphalt mixture.The paper researches the determining method of various parameters and calculating means of gradation composition on base of AM AP design method for two types of mixtures used commonly at present, that is dense-graded asphalt mixture and stone mastic asphalt (SMA) and according to the actual situation in our country. Through a lot of mechanical and pavement performance experiments, it is analyzed thoroughly the correlative rules between AM, AP and water stability, resistance to rutting at high temperature, low temperature crack resistance and skid resistance of asphalt mixture. Thus, the range of AM, AP is suggested for the two types of mixtures respectively according to the climatic condition and pavement performance requirements at different areas prescribed in criterion, which can be referrible while designing asphalt mixture gradation. Based on these results, a method of asphalt mixture design considering pavement performance is put forward and is applicable to different types of asphalt mixtures. That offers a new way of asphalt mixture gradation design.