Evaluation of durability and functional performance of porous polyurethane mixture in porous pavement

Porous pavements bring significant benefits in traffic safety and noise reduction. This study aims to investigate durability and functional performance of Porous Polyurethane Mixture (PPM) as an alternative to Open-Graded Friction Course (OGFC) in porous pavements. Two-component polyurethane was used to prepare PPM with different binder contents and aggregate sizes. The anti-clogging performance of PPM was evaluated through clogging test and permeability measurements. The raveling resistance of PPM was evaluated using Cantabro loss test considering different temperature, moisture, and freezing conditions. The cooling and quiet effects of PPM were investigated using the measured temperature and rubber contact noise in the laboratory setup. The clogging test results indicate that the PPM has better resistance to particle-related clogging caused by filtration of soil suspensions as compared to OGFC. Similarly, the permeability testing results show that the PPM maintains high permeability during the rutting test at high temperatures; while the permeability of OGFC decreases significantly. The Cantabro loss test results indicate that the PPM with 6% polyurethane content and the maximum particle size of 9.5 mm shows much less raveling potential than OGFC at different testing conditions. The increase of polyurethane content and the larger aggregate size can improve raveling resistance of PPM. The internal temperature of PPM specimen is lower than that of asphalt mixture specimen and OGFC specimen under the same sunlight exposure. On the other hand, the PPM has the greater acoustic absorption than OGFC, especially for tire vibration noise.