A highy topical subject in the contribution of road construction to sustainable development is the production of asphalt mixtures at lower temperatures (reduced-temperature asphalt, RTA), because of the advantages from the energy, environmental and engineering points of view. Within a project on European test methods for bituminous mixtures and binders that was initiated by the Belgian Bureau for Standardization (NBN) and aims among other things at improvements with a view to sustainable development, BRRC has undertaken to closely monitor the recent developments and achievements in the field of RTA, both in Belgium and abroad. This includes the following aspects:
This was also a small sequel project to SILVIA, which was funded under the 6th EU Framework Programme. It was carried out by a consortium of BRRC, DRI and FEHRL. The object was to disseminate the knowledge on low-noise pavements gained in the SILVIA project to countries which had not participated in SILVIA. A number of one-day workshops were held in six countries (Slovenia, Romania, Switzerland, Ireland, Portugal, and Greece). In addition, a European working group on the Acoustic classification of road surfaces was formed, which held its first meeting in Ljubljana in April 2008 and its second in Copenhagen in September 2008.
The purpose of this method is to determine the acoustic quality of a given road pavement at a well-defined location. BRRC performs this test according to the specifications given in the relevant standard ISO 11819-1. A sound level meter and a tachometer are installed on the roadside to measure the maximum sound pressure level and the speed of a large number of randomly sampled passing vehicles. The results are statistically processed into an SPB index (SPBI), which is a good measure of the acoustic quality of the pavement at the measuring site – more particularly, of the influence of the pavement on traffic noise load for local residents. A full description of the test can be found in BRRC’s leaflet F67 “La méthode Statistical Pass-By (SPB)”.