Rheological multi-scale evaluation of RAP and RAS binders mobilisation in hot mix asphalt

Abstract

The use of Reclaimed Asphalt Pavement (RAP) and Recycled Asphalt Shingles (RAS) in asphalt mixes is a constructive solution allowing economic, environmental and technical benefits. The objective here is evaluating the binder mobilisation rate of recycled materials by predicting the viscoelastic (LVE) behaviour of the asphalts from the LVE of their theoretical binder. The multi-scale approach adopted here goes from the binder scale to the mix scale. At the binder scale, after the extraction/recovery of RAP and RAS binders, several bitumen blends were produced and characterised by conventional and rheological tests. At the asphalt scale, the LVE behaviour of several mixes containing RAP and RAS was characterised using complex modulus test. Then, Shift-Homothety-Shift-time-Shift-transformation (SHStS) was applied allowing verifying the correspondence degree between the experimental behaviour and the predicted one. The results confirm that the totality of the RAP binder was mobilised and up to 50% in the case of RAS.

KEYWORDS:

• Mobilisation rate
• active binder
• reclaimed asphalt pavement (RAP)
• recycled asphalt shingles (RAS)
• SHStS transformation
• rheology

Acknowledgements

The authors gratefully acknowledge the successful collaboration and the immense academic support carefully provided by the staffs of both ETS Montreal and ESTP Paris laboratories.

Author contributions

Conceptualisation, methodology and validation by A.D (Abdeldjalil Daoudi), A.D., D.P., A.C. and writing—original draft preparation by A.D (Abdeldjalil Daoudi).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was partially funded by the project R802.1 for Transport Quebec.