Properties of Mixtures with High Percentages of Reclaimed SBS–Modified Asphalt Pavement

Abstract

Increasing the percentage of reclaimed styrene-butadiene-styrene (SBS)–modified asphalt pavement (RAP-SBS) is a promising way to promote the development of sustainable roadway systems. The excellent properties of RAP-SBS are the key to its application in high percentages. This study evaluates the properties of hot mix asphalt (HMA) mixtures with 0%, 30%, 50%, and 70% RAP-SBS replacement in terms of rutting, low-temperature anticracking, and moisture susceptibility. The dynamic modulus test evaluates the stiffness. Both unaged and long-term aged (LOTA) samples are evaluated. Moreover, the effect of freeze-thaw (F-T) cycles on the splitting strength is also investigated. The results show that the RAP-SBS is feasible to recycle, and HMAs mixture with higher percentages of RAP-SBS exhibit better rutting resistance, and lower anti-cracking properties and moisture susceptibility. When the RAP-SBS percentage is less than 30%, the anticracking property of the recycled mixture is basically close to that of HMA mixture between −20 to −10°C, and the moisture susceptibility of the two types of mixture is similar when the percentage is less than 50%, but the durability of both recycled mixtures is poor. In addition, no continuous increase in dynamic modulus is demonstrated as the RAP-SBS percentage increases. When subjected to F-T cycles, the strength of mixtures with RAP-SBS is more sensitive than that of HMA mixtures, especially for mixtures with high RAP-SBS percentages.