Performance of hot-mix asphalt produced with double coated recycled concrete aggregates

摘要

This paper evaluates the performance of hot-mix asphalt (HMA) made with double coated recycled concrete aggregates (DCRCAs). It is aimed to assess the performance properties of HMA made with DCRCA such as rutting, fatigue, and dynamic modulus. The recycled concrete aggregates (RCAs) was coated with cement slag paste (CSP) and Sika Tite-BE to enhance its strength and durability. Mixtures were produced to have 0%, 20%, 40%, and 60% of DCRCAs. The results indicated that the addition of DCRCAs to HMA can decrease the permanent deformation resistance of HMA, but DCRCA-asphalt mixtures still maintained acceptable performance against rutting. The results of flow number (FN) test, however, showed that mixes with 40% and 60% DCRCAs achieved higher resistance against rutting when compared with control mix. The fatigue life of mixes made with DCRCAs was longer than that of the HMA prepared with control aggregates. In addition, the dynamic modulus of DCRCA-mixes was found to be lower than that of control mix at low temperature. Bituminous mixtures produced with DCRCA, however, showed higher dynamic modulus when tested at high temperature (40 degrees C). Although the results obtained from this study are satisfactory, DCRCA-asphalt mixtures require further investigation particularly to assess their mechanical characteristics in the field. (C) 2019 Elsevier Ltd. All rights reserved.