Acoustic Maintenance of Pavements by Large-Scale Grinding

Abstract

A so-called semi-dense asphalt (SDA) is widely used in Switzerland as a low noise pavement. During 2018, our preliminary grinding tests on small SDA sections and subsequent broader tests have shown that grinding is an effective way to regain −3 to −5 dBA, measured with the close-proximity (CPX) method. The main purpose of this paper is to put forward a large-scale maintenance process which is effective in regenerating the acoustic performance of aged SDA wearing courses for entire road sections. A secondary purpose is to observe the effect of the same grinding method on dense pavements like AC, ACMR and MA. Several roads at different locations and environmental conditions have been tested in early 2019. At each location the treatment was evaluated by the measurements of grinding depth, mean texture depth and CPX rolling noise. Acoustic effectiveness of the grinding method depending on the pavement characteristics are examined. Our first results indicate that all the treated surfaces become less noisy, regardless of grain size or pore volume. The incidence of grinding on reshaping the surface texture in a way that facilitates air pumping and diminishes tyre vibration will be discussed.