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:
The development of new applications and the constantly increasing demands on roads create a permanent need for innovative and improved types of asphalt that ensure higher performance and durability. Mix design with the PradoWin software package (see Components and mix design) and the set of performance tests on asphalt mixtures (see The development of tests for bitumens and asphalt mixtures) for which BRRC has equipped itself make it possible to develop new and optimize existing types. This is often followed by the construction and monitoring of test sections in cooperation with road authorities, which may result in recommendations and specifications.
This project originated from the search for an alternative to conventional porous asphalt, which, while retaining the many advantages (acoustical properties, drainability, skid resistance, resistance to rutting) of this type of mixture, was required to reduce or limit its disadvantages (winter behaviour and durability).
In this project several variants were developed, some of which were based on the French EME (“enrobé à module élevé”). After extensive testing in the laboratory ten variants were laid in 2006 on a heavily trafficked section of the E19 between Brussels and Antwerp. This was followed by the drafting of recommendations and performance specifications for this type of asphalt mixture, in cooperation with the Flemish department of mobility and public works (MOW). All information on this project can be found in a research report (CR43/07) published by BRRC.