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:
To help designers (or decision-makers) with the choice of pavement type, a working group of experts (engineering consultants, contractors, public authorities and researchers) in the fields concerned has compiled a code of good practice for the choice of asphalt pavement type in road design and maintenance (BRRC publication R78/06).
This four-year project (July 2006 – June 2010) was funded by the Belgian Bureau for Standardization (NBN). Its objective was:
to improve the procedures for the extraction (with a continuous flux centrifuge) and recovery (with a rotary evaporator) of binders from bituminous mixtures prepared with polymer-modified bitumens (PmBs) (EN 12967-1 and -3);
to study and improve the procedure for the determination of binder content by ignition (EN 12697-39).
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.