Deterioration of the Noise Reduction Performance of Polyurethane Porous Elastic Mixture under Void Clogging and Thermal-Oxidative Aging Conditions

Low-noise pavements, particularly polyurethane pavements with sound absorption and vibration reduction characteristics, are an effective way to reduce traffic noise. However, the noise reduction performance of polyurethane porous elastic mixtures (PPEM) gradually deteriorates owing to void clogging and thermal-oxidative aging. This study investigates and characterizes the noise reduction performance of PPEM influenced by these factors. The tire noise reduction performance of a prepared PPEM was measured based on void-clogging, thermal-oxidative aging, and tire noise tests. The results indicate that the pavement performance of the PPEM meets the Chinese specification requirements, and its dynamic stability can be up to 120,000 times/mm. The void ratio was found to be the most important factor affecting the noise reduction performance of the mixture, and, at a constant void ratio, the PPEM outperformed a porous asphalt concrete mixture. With increased thermal-oxidative aging time, the noise reduction performance of the PPEM first increases and then decreases and is likely to gradually decrease owing to the aging of polyurethane and crumb rubber.