Noise reduction effect and mechanism of ultra-thin friction course with a 3-mm NMAS

To develop durable and low-noise asphalt pavements, this study developed an Ultra-Thin Friction Course with a Nominal Maximum Aggregate Size(NMAS) of 3 mm (UTFC-3) using the Coarse Aggregate Void Filling (CAVF) method, achieving a dense skeleton structure and asphalt film thickness exceeding 15μm. Laboratory tests and 3D laser scanning confirmed that UTFC-3 meets all key performance requirements, including high-temperature stability, moisture resistance, and skid resistance. Through vertical tire-drop noise tests, impedance tube measurements, and dynamic mechanical analyses, UTFC-3 demonstrated a significant noise reduction of 2.9-10.1 dB(A), with pronounced effects in mid-to-high frequency ranges. The noise reduction mechanism is attributed to an optimized surface texture that suppresses mid-to-high frequency tire-pavement interaction noise (250–20000 Hz) and enhanced damping properties that attenuate low-frequency (<250 Hz). Field validation further supports its acoustic efficacy, offering a durable and low-noise pavement solution for urban environments. • Developed novel Ultra-Low-Noise Friction Course with 3 mm NMAS and >15 μm asphalt film. • Satisfied all critical performance requirements. • Achieved synergistic TPIN reduction via dual texture-damping optimization. • Validated significant TPIN reduction vs conventional pavements through lab/field tests. • Established texture-damping synergy mechanism for low-noise pavement.