A novel high-performance warm-mix porous asphalt prepared with polyurethane prepolymer: Strength development mechanism and mechanical and functional performance

The relatively poor durability of porous asphalt (PA) is one of the major concerns that limit its wider application. One common approach to enhance the durability of PA is to use high-viscosity polymer-modified asphalt binder. However, this method can result in increased construction temperature, thus raising various associated environmental concerns. The aim of this study is to explore the potential of using polyurethane prepolymer modified porous asphalt (PUPA) as a novel high-performance PA with relatively low construction temperature. The optimum polyurethane prepolymer (PUP) content and compaction temperature of PUPA were first determined through the Marshall test and compaction energy index (CEI). Then, the strength development of PUPA was characterized by the indirect tensile stiffness modulus (ITSM) test. The engineering performance of PUPA was evaluated by means of the Cantabro abrasion test, indirect tensile fatigue (ITF) test, wheel tracking test, and freeze-thaw splitting test. The results showed that the optimum PUP content was 10%, and the compaction temperature of the PUPA can be as low as 130 degrees C. The curing reactions between PUP, aggregate and airborne moisture was found to contribute to the strength enhancement of PUPA. Moreover, the overall performance of PA can be significantly improved with the incorporation of PUP. This study proved the high potential of building low-carbon durable PA pavement with PUPA.