How not to design 100% recycled asphalt mixture using performance-based tests

Abstract

Performance-based mixture tests were used to design 100% recycled mixtures while verifying the potential to use the test methods for routine design of highly recycled asphalt mixtures. Two different gradations of recycled mixtures were prepared, each with two different binder contents and a polymer modified bitumen for one of the mixtures. A bio-based rejuvenator was always applied to ensure the targeted binder grade. The results demonstrated that it is possible to design a 100% mixture with rutting resistance, fracture toughness, and stiffness performance at the level of a conventional AC8 mixture. However semi-circular bend fracture toughness test at 0°C was not sensitive enough to changes in binder content and its properties therefore it is not recommended for using in mixture design optimisation of highly recycled asphalt.

GRAPHICAL ABSTRACT

Keywords:

• performance-based asphalt design
• balanced design
• rutting
• cracking
• master curve
• stiffness

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Bundesamt für Umwelt [grant number UTF 489.19.14/IDM 2006.2423.487].