A methodology to evaluate pavement noise performances for characterisation, checking and monitoring purposes
Résumé
Over the past decade, road industry developed efficient low noise pavements, providing rolling noise reductions up to 8 dB(A) compared to traditional dense asphalt pavements. With such a progress, road authorities are willing to introduce noise requirements in the tenders for road surface renewal. This implies that a general framework is accepted by both parties, defining the noise performance and describing the procedures to characterise or check it on site. Consequently, the National Working Group for Road Surface Characteristics (GNCDS) was tasked to develop a methodology to evaluate pavement noise performances for characterisation, checking and monitoring purposes. The members of GNCDS belong to public road authorities or institutes and private road companies. In this way, the methodology to be developed should integrate the concerns and possibilities of all stakeholders. In particular, special attention was paid to the difficulties that road contractors often face to reproduce noise performances of a given pavement product from one work site to another, due to unavoidable variations in the properties of aggregates or binder, in the laying process or in local practices. The methodology proposed is based on the method developed within the “SILVIA” EU project, but introduces several adaptations and simplifications to improve the practicability. Noise performance is defined by an absolute pass-by noise level at a reference speed (90 km/h in France). Therefore, the noise characterisation of a pavement is performed by a SPB measurement. At least two different sections on different sites with less than 1.5 dB(A) difference in noise levels, are necessary to define an average noise performance of the pavement product. A CPX measurement is also performed in parallel, to be used as a reference for the checking procedure of other sections of the same type of pavement. The paper will present the methodology developed, the experimental tests performed to check its applicability. Then some successful examples of application of this methodology will be presented.