Abstract
The use of recycled concrete aggregate (RCA) in asphalt mix is a sustainable construction practice, provided that the addition of RCA does not adversely affect the performance of the asphalt mix. In this study, the effects of RCA on the performance behavior of hot mix asphalt (HMA) were examined. The mixes were produced by blending RCA with virgin aggregate at six different percentages (0 %, 20 %, 40 %, 60 %, 80 %, and 100 %). The mix design results indicate that the RCA is highly absorptive, and that as the percentage of RCA in the mix increases, the optimum asphalt content increases significantly. In terms of performance behavior, the addition of RCA to the HMA mix reduced the modulus, resistance to rutting, fatigue, thermal cracking, and resistance to moisture damage of the asphalt mix. Considering the performance behavior and the need for a higher asphalt content, the use of RCA as HMA aggregate is not recommended, even though all the RCA mixes met the volumetric requirements. More important, the findings in this study indicate that the absorbed asphalt might play a significant role at high temperatures, likely because of expansion of the asphalt.