Alternative Laboratory Characterization of Low Rolling Resistance Asphalt Mixtures: Fid-Bau Portal

Alternative Laboratory Characterization of Low Rolling Resistance Asphalt Mixtures

Pettinari, M. / Nielsen, E. / Schmidt, B.

A project named COOEE, financed by the Danish Innovation Fund, was commenced in 2012. This project dealt with reduction of CO₂ emissions by exploitation of rolling resistance modelling of pavements. The challenge was to establish a scientific background for the development of pavements with low rolling resistance that satisfy safety standards and provide at least 15 years durability. Stone mastic asphalt (SMA) is the most common surface layer adopted on the Danish road network and the COOEE project aimed at optimizing the mix design with the goal of reducing rolling resistance. The optimization procedure has led to mixes fulfil the project objectives but at the same time exhibited deficiency in texture stability and durability. An extensive laboratory investigation has been completed in order to identify the deficiency sources and suggest appropriate solutions. In this connection, a study of workability and mechanical properties of COOEE mixtures, supported by a rheological characterization of the adopted binder, was conducted and compared to those measured on a conventional SMA. The investigation results highlight the importance of providing a proper compaction degree—as a fundamental requirement for achieving desired mix performance. It is also found that investigating binder properties with a dynamic shear rheometer is essential for gaining better understanding of mixture response.