French Enrobés à Module Élevé Class 2 (EME2) technology offers the prospect of reduced asphalt thickness for heavy duty pavements, and lower construction and maintenance costs.
Austroads has released a report detailing the first year of a three-year project to transfer EME2 technology to Australia.
EME2 mixes are produced using a hard paving grade bitumen applied at a high binder content (approx. 6%). Compared to conventional asphalt bases with unmodified binders, high modulus asphalt is characterised by high stiffness, high durability, superior resistance to permanent deformation and good fatigue resistance. International experience indicates that significant pavement thickness reductions can be achieved using EME2.
In this first year of the project, an Australian specification framework for EME2 mixes was developed and the requirements for manufacturing, paving and compliance were provided.
Tentative specification limits for EME2 mixes were set using Australian test methods for workability, wheel tracking, flexural stiffness, fatigue, and moisture sensitivity.
As part of the validation process a successful demonstration trial was carried out on Cullen Avenue West, Eagle Farm, Queensland.
Data from the laboratory and field studies was analysed and the outcomes are summarised in the report. Based on the laboratory and field data collected so far, the EME2 pavement shows performance as expected.
The EME2 test section at Eagle Farm, which is 30% thinner compared to the DG20HM control section, shows similar performance in terms of structural capacity. Preliminary laboratory data suggests that EME2 mixes have superior resistance to moisture damage, rutting and fatigue; however, long-term field data is required to confirm and validate these findings
This project supports the move towards a unified performance-based mix and pavement design for asphalt in Australia.
In the second year of the project, a draft EME2 mix design guideline will be developed.