Monitoring Road Acoustic and Mechanical Performance

In the last decades, noise pollution has become a criticality, especially in residential areas. In more detail, the traffic noise produced by the interaction between tire and road surface (rolling noise) represents one of the main sources of urban noise. Tire characteristics (type/construction, size, belt stiffness, tire damping, non-uniformity, rubber hardness, wear and ageing, retreaded, studded, tread pattern and porosity, and tire cavity content) and road properties (e.g., acoustic absorption, surface texture, porosity, and mechanical impedance) greatly affect rolling noise. In particular, the mechanical impedance of pavement is defined as the ratio of a force applied on a structure to the induced velocity, where these latter are frequency-dependent vectors. Despite efforts and studies, mechanical impedance real effect on rolling noise is still a critical issue. Consequently, this study aims at shedding the light upon the relationship between acoustic response and mechanical impedance of road pavements. By using an impact hammer and a 3D accelerometer, several tests were performed on different types of samples and materials according to the EN 29052-part 1. Results were derived in terms of mechanistic (modulus, damping ratio, dynamic stiffness) and acoustic parameters. Based on results, both changes of the structural health status of pavements and their mechanical impedance affect the acoustic response.