Perpetual pavements are flexible, full-depth asphalt pavements designed to last more than 50 years, but the principle isn’t part of the Australian industry standard.
Perpetual pavements are a globally recognised methodology and constitute only part of Australia’s roads according to Rob McGuire, chairman of a new industry body dedicated to the advancement of the Australian flexible pavements sector.
The Australian Asphalt Pavement Association’s (AAPA) National Technology and Leadership Committee (NTLC) was launched in late 2014 and research into solutions of perpetual pavements is one concept that’s been explored.
New research into the field of Fatigue Endurance Limit (FEL) is one area AAPA’s NTLC has focused on in the progression of the concept of perpetual pavements in Australia.
“This [FEL] is now an internationally accepted principle and AAPA is seeking to have this embedded into the design approach on Australian freeways,” he says.
A three-year joint research program between AAPA’s NTLC and Austroads explored the FEL concept, completing their research earlier this year.
FEL is a principal that shapes the design of Perpetual Pavements so that they’ll never crack from the base of the pavement structure. Surface rectification is only necessary every 15 years.
“This design approach will save many millions of dollars per kilometre of road, and delivers the optimal use of scarce resources,” says Mr. McGuire. “The next step is to get across to the engineering fraternities that the methodology and the data is sound.”
Headed by a group of nationally recognised industry figures from companies such as Boral, Fulton Hogan, Colas and Downer, AAPA’s NTLC aims to bring together the technological functions of the industry under one roof and to put some validity into existing ideas, such as perpetual pavements.
The goal is to give a renewed focus and clear direction to drive the flexible pavements sector, but also to develop comprehensive communications strategies.
The co-ordination, development and delivery of innovation across Australia and the establishment of partnerships with state road authorities and research institutions are a few of the key directives for the committee.
Essentially AAPA’s NTLC is a committee that is “formed by industry, for industry,” as Mr. McGuire puts it.
He adds that it’s a diverse group of individuals making up the NTLC. “We’ve introduced three operational people with the goal of improving the balance between a purely technical view and the operational view.”
“The advancement of technology in the flexible pavements field over the next 10 years is anticipated to be dramatic and will deliver a new way of delivering roads in Australia,” he says. “AAPA’s NTLC fills a gap for the direct industry engagement in the research and development field in Australia.”
He says that AAPA has high-end technical skills to guide and assist the formulation of research programs and bring the best people together to advance the industry knowledge base. As he puts it, it’s not necessarily a place for things to happen immediately, but it’s being used as a forum to raise ideas and take the industry to another level.
The industry direction of AAPA’s NTLC is clear, but the well-established methodology of the current industry has its obstacles for the committee.
“There will be a lot of entrenched standard practice, personal opinions and resistance to change,” he says. “I think it’ll take a bit of time to be seen as a peak committee.”
He adds that with the states governed by their own laws and basically on different levels, it’s a long road ahead.
Mr. McGuire explains that AAPA has a long history of participation in this area and the formation of AAPA’s NTLC provides leadership and direction for the future.
Since the 1980s, AAPA has pushed to introduce new testing methods into the country to better determine the performance of the materials and technologies used to build Australia’s roads.
“Moving the industry towards a total service outcome for road agencies where AAPA members can undertake the pavement engineering, materials selection, construction and long-term maintenance requires a sound grounding in technology, which is the key ongoing function for the NTLC,” he says.
Mr. McGuire says that the introduction of new technologies will change the way in which road authorities undertake pavement preservations and local authorities provide a smoother, safer road surface for their communities.
Examples include “thinlays” – finer asphalt mixes specifically designed for preservation – and enrobés à module élevé (EME) – French high modulus hot mix asphalt technology.
The implementation of research and development into the concept of FEL has already proved a fruitful first step for AAPA’s NTLC, and Mr. McGuire says there are more key areas the committee is focusing on.
AAPA’s NTLC is formulating a research direction for pavement engineering, bitumen spray sealing, asphalt, and bitumen binders. This move, Mr. McGuire says, requires significant work and the completion of key research programs in these areas.
“A move to true performance-based specifications for the delivery of flexible pavements will usher in a new era of innovation for industry and deliver better value for money outcomes of the taxpayers,” he says.