RELATIONSHIP BETWEEN VOID FEATURE AND ROAD PERFORMANCE OF POROUS ASPHALT MIXTURE BASED ON IMAGE TECHNIQUE

摘要

Asphalt Marshall Tests are done on asphalt mixture samples of PAC-13 and PAC-16 with three different aggregate gradations, and the distribution of effective voids in them is attained by use of COSMOS image technique. The relationship between distribution features of effective voids in asphalt mixture and its road performance is analyzed, and following conclusions are attained. The connectivity and distribution characteristics of voids in porous asphalt mixture can be described qualitatively by the image of effective voids. The bigger the maximal particle size of aggregate is, the bigger the effective voids are in same area. The range of effective void is from 6.5 % to 12.8 %. The splitting strength and Marshall stability of porous asphalt mixture decrease with the increase of air voids or area fraction. The permeability coefficient of porous asphalt mixture increases with the increase of air voids or area fraction. The effective void area is accordant with the void of porous asphalt mixture, and it can be used to analyze the distribution characteristics of effective voids in open-graded friction course and the changes of road performance.