Asphalt Review - Volume 29 Number 2 (June / July 2010)

ASPHALT REVIEW
$1 Million AAPA/Austroads Warm
Mix Asphalt Validation Project
In today’s world we must all
take care of our environment.
For those in the pavement
industry, we must also ensure
that pavements are safe,
smooth and long lasting.
Asphalt pavements are low
emitters of greenhouse gas
and the bitumen not consumed,
remaining 100% recyclable.
Asphalt pavements are also
safe to drive on, easy and quick
to resurface when required and
are smooth to ride on.
But as an industry, we recognise
the importance of always
seeking new ways to make even
better roads. AAPA industry
and government members are
working together on a major
project to validate warm mix
asphalt for Australia.
Warm mix asphalt uses less
energy than hot mix during
the production process. It also
has a number of other potential
benefits. The joint AAPA/
Austroads Validation project
is therefore a major project
supporting the early adoption
of this technology in Australia.
• Improved safety benefits as the
materials and asphalt are at lower
temperatures compared to hot mix,
creating a safer workplace;
• Improved productivity as deep asphalt
works can be opened to traffic more
quickly. This benefits the transport
industry and commuters by reducing
the length of time roads are under
repair;
• Extended paving seasons; and
• Longer haul distances.
The effectiveness of this green
technology has been proven through
ongoing implementation in Europe and
the United States, and in other countries
around the world. It is also expected to
become standard practice for asphalt
production in these countries. However,
state road authorities have advised
that they want WMA to be validated in
Australia, using normal material, plant
and procedures, before it is used on
major road projects.
To validate WMA in Australia, AAPA in
conjunction with state road authorities,
developed an evaluation protocol to
guide validation projects. This protocol
was developed through the Asphalt
Research Reference Group (ARRG), a
group comprising state road authorities
and the AAPA National Technology
Committee. ARRG advises the Austroads
Pavement Technology Review Panel on a
wide range of issues relevant to asphalt.
Details of the protocol are provided at
the end of this article.
Having developed the validation
project protocol, AAPA then worked
with state road authorities and industry
members to obtain support for a major
validation project that would enable
several different WMA processes to be
validated against standard hot mix under
heavy traffic conditions.
After assessing a number of sites with
staff from VicRoads, a suitable site was
selected. This site is a heavily trafficked
three lane section of the Hume Highway
in northern Melbourne; a section that
carries between 6,500 and 8,500 vehicles
per day on each lane. The site was
already scheduled to have a new wearing
course under VicRoads programmed
maintenance program.
The decision to use a wearing course
on a multiple lane urban highway with
heavy traffic was made to ensure the
project would demonstrate the field
performance of WMA in a very difficult
environment.
VicRoads funded the costs of the asphalt
materials under its maintenance budget
and the three major asphalt producers
– Boral Asphalt, Downer EDI Works
and Fulton Hogan – agreed to provide
AAPA, in conjunction with Austroads,
has commenced a major project to
validate the performance of Warm Mix
Asphalt (WMA) in Australia. The AAPA/
Austroads WMA Validation Project is a $1
million project comparing several WMA
materials against control sections of Hot
Mix Asphalt (Hot Mix). The project aims
to demonstrate that WMA has the same
performance as hot mix asphalt and is
managed jointly by AAPA and ARRB (on
behalf of Austroads).
WMA is asphalt made at lower
temperatures than conventional hot mix.
It requires less energy to manufacture
and consequently produces less
greenhouse gas. WMA also has a range
of other significant benefits including:
The WMA Validation Site prior to the start of works.
18 ROADS JUNE 2010/JULY 2010