The use of compressible packing model and modified asphalt binders in high-modulus asphalt mix design

Abstract

High-modulus asphalt mix, Enrobé à Module Élevé (EME) in French, is a type of HMA representing high modulus or stiffness. Traditionally, EME mixes are fabricated with straight-run hard grade asphalt cement which has poor performance at lower temperatures and is very susceptible to low-temperature cracking in cold regions. The main objective of this study is therefore developing a new approach to EME mix design that contributes to good performance at high, medium and low temperatures. EME mixes have a dense structure. In this regard, Compressible Packing Model (CPM) was used to optimise the packing degree of EME mixes for two different mix types based on nominal maximum aggregate size (EME 12.5 and EME 19). In addition, three types of modified asphalt binders, namely: PG 88-28, PG 82-28 and PG 58-28 plus 10% Elastomer additives were used in this study. Thermo-mechanical tests were conducted to evaluate the performance of EME mixes in terms of stiffness, rutting, fatigue and low-temperature cracking. Obtained results showed that the developed mixes had acceptable performance at all levels, and that the mixes could satisfactorily perform at lower temperatures.

Keywords:

• Enrobé à Module Élevé
• low-temperature performance
• aggregate packing
• high-modulus asphalt
• high-performance mix

Acknowledgements

The authors would like to thank McAsphalt Industries Ltd, Bitumar Inc. and Roadway Solutions for their support on materials preparation.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Taher Baghaee Moghaddam http://orcid.org/0000-0002-2297-1567

Additional information

Funding

This work was supported by the Ministry of Transportation Ontario (MTO) through the Highway Infrastructure Innovation Funding Program [HIIFP-2015].