Study On Composition Design And Applicability Of Large Stone Porous Asphalt Mixes

In recent years, due to the influence of theory of strong foundation and thin pavement, semi-rigid base is still the primary solution of base design scheme for expressway pavement structure type. But the current development characteristics of traffic load show new trends of “overload, rapidness, channeling”, which lead to the problem of refection cracking and water damage prominent increasingly caused by defects of semi-rigid base itself. Large stone porous asphalt mixes are new approach of flexible base design for asphalt pavement, which can effectively alleviate the present situation of refection cracking widespread and water damage occurred untimely. The research on composition design and applicability of LSPM was carried out based on the reference of research results and practical experience at home and abroad.Firstly, the applicability of MAC modified asphalt as binder of LSPM was carried out by testing the static flow performance, leakage performance and thermal performance, and the sample preparation temperature of LSPM was recommended with laboratory test. The strengthen formation mechanism and grading design of LSPM were introduced, also the large Marshall molding method, volume parameter determination method, OAC determination method. The mix proportion of LSPM-30 was determined with Marshall grading design method, and then the research on high temperature stability, water stability, permeability and fatigue properties of LSPM-30 was analyzed. Compared with AC-25 dense gradation asphalt mixture, the social and economic benefits were analyzed and evaluated.Laboratory tests data analysis showed that LSPM has good high temperature stability, water stability, permeability and fatigue properties, and can effectively alleviate the present situation of refection cracking widespread and water damage occurred untimely. Compared with the traditional semi-rigid base materials, LSPM shows obvious technical superiority.