Rubberized asphalt mixtures: a novel approach to pavement noise reduction

Noise, which is defined as unwanted sound, is present everywhere whether at home, in an office, or on the road. When noise reaches a certain level, it becomes annoying or uncomfortable to the human ear. Highway noise is one such noise that has become a serious issue in many cities in the United States. Highway noise eminates from three main sources of a vehicle: the interaction between the tires and the pavement, engine and exhaust noise, and noise resulting from the aerodynamic effects of the vehicle. In an effort to mitigate highway noise, local, state, and/or federal agencies typically construct noise barriers adjacent to highways. These barriers effectively reduce the noise hears by those located behind the barrier, but this method of noise reduction can come at very high cost in some cases. In addition, some sound barriers are not aesthetically pleasing to the public. An alternative to constructing noise barriers is to address the highway noise problem at the source with the use of rubberized asphalt concrete as a surface course on the highways. Such rubberized asphalt mixtures have been proven to reduce the noise generated by the interaction between the vehicle and the pavement resulting in perceived noise reduction of 50% in some cases. Not only does the rubberized asphalt reduce noise generation, but it also provides more durable pavements that are less susceptible to the effects of temperature.