On the Use of Recycled Asphalt and Trinidad Lake Asphalt (TLA) for the Preparation of High Modulus Asphalt Concrete

Abstract

Rutting of asphalt pavement occurs earlier and is more serious under the increasingly heavy traffic load conditions that can be found in subtropical monsoon climate regions. High modulus asphalt concrete (HMAC) with excellent anti-rutting and anti-fatigue properties is generally used to mitigate this issue. Given the relatively high cost of the additives used in this type of asphalt, in this study the feasibility of using recycled asphalt mixture (RAP) and Trinidad lake asphalt (TLA) for the preparation of HMAC is considered. The mineral composition of the RAP is first analyzed, then the TLA modified asphalt with different levels of RAP content is used to assess the effect of RAP on the performance of the mixture. Finally, the high-temperature rheological properties of extracted bitumen and the adhesion characteristic between mineral and bitumen are analyzed. The results show that after RAP combustion, the yellowish and greyish minerals display different alkalinity values, while the greyish mineral exhibits an improved ability to combine with bitumen. Thus, RAP can significantly enhance the high-temperature rutting resistance of TLA modified asphalt mixtures. The aged bitumen in RAP makes the mixed binder harder and improves its rheological properties at high temperatures.