Two-Layer Porous Asphalt: Main Properties to Decrease the Noise Emissions

Road transportation is one of the major sources of noise emissions that seriously affect human health. The porous surfaces of roads are sound absorbing, which helps to reduce noise pollution. For this purpose, different two-layer porous asphalt mixtures were evaluated both mechanically and functionally, to develop an asphalt mixture that reduces the noise generated between tires and road. This research focused on the variables that determine the main properties to be considered: texture wavelength spectrum, acoustic absorption, and flow resistivity. Void content, thickness, and maximum aggregate size were identified as the variables that should be controlled to decrease noise emissions.