Optimization of Recycling Technology Based on Grey Correlation Analysis

Eight experiment plans varied with 3 recycling technologies at two test level were designed and Marshall indexes (bulk density gamma(f), air void VV, void of mineral aggregate VMA, Marshall stability MS) and performance indexes(residual stability RS, freeze-thaw stability ratio TSR, low-temperature bending strain LBS, dynamic stability DS) of 8 recycled asphalt mixtures produced by 8 different kinds of recycling technology were tested. Moreover, Grey system theory was used to calculate the grey correlation grade so as to comparatively evaluate the pros and cons of different recycling technologies and recommend the best. The results showed that the recycling technology has significant influences on the Marshall index and road performances. The recycling technology of higher preheating temperature of RAP, rejuvenating agent added to RAP and increasing mixing time will enhance overall performances of recycled mixture; Grey correlation analysis is a kind of simple and effective material assessment method which can overcome the disadvantage of the single target design being not able to pay attention to other performances.