Laboratory and Field Evaluation of a Thermoplastic Powder Coating for Functional Enhancement of Asphalt Pavement

Asphalt pavement has a strong capacity for heat absorption, leading to increased surface temperatures during summer. Additionally, the rise in automobile exhaust significantly impacts the environment. In this study, two types of thermoplastic resin powder coatings (TPC) were developed: thermoplastic polyurethane elastomer powder coatings (TPUPC); and ethylene-vinyl acetate copolymer powder coatings (EVAPC). These TPCs were designed to reduce pavement temperature and degrade exhaust. Laboratory tests were conducted to optimize the TPC formulation and evaluate its cooling effect, exhaust degradation performance, surface properties, and durability. In addition, two field sections were constructed to investigate the field applicability of TPC. The results showed that asphalt mixture specimens sprayed with 100 g / m 2 of TPC achieved a temperature reduction of approximately 8°C. while the degradation rates for NO and CO reached about 50% and 15%, respectively. Further, the durability of the TPC and the performance of the pavement after TPC application are satisfactory. Under the same spraying dosage, TPUPC outperforms EVAPC in most performances. As the spraying dosage increases, skid resistance, abrasion resistance, and antiglare performance decline, while adhesion strength and impermeability improve. Considering these performance characteristics, a spraying dosage of 100 g / m 2 was recommended for TPC application. Preliminary in situ tests also indicated that TPC could provide a certain cooling benefit while maintaining acceptable skid resistance and antiglare performance under field conditions.