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

ASPHALT REVIEW
See Table 1. for a comparison of
typical temperatures (degrees C)
measured on a trial carried out on 10
March 2010 in Queen Street for the
Parramatta Council.
More benefits with LoCarb
“LoCarb is a win-win for the environment
and from a sustainability perspective,
with a simultaneous reduction in energy
consumed and emissions generated
during the manufacturing process,” says
Boral’s Asphalt Technology Manager,
Trevor Distin.
There is also a saving in the amount
of non-renewable raw materials such
as bitumen and aggregates required to
produce asphalt.
The benefits of using LoCarb asphalt
extend further than those already
mentioned.
“The lowering of application
temperatures means that we are now
able to achieve the same, if not better,
compaction and production rates in the
field. This is because the mix compacts
more uniformly and allows us to open it
to traffic sooner,” Mr Distin says.
“On a recent job the temperature was
measured behind the paver for both a
traditional hot mix and LoCarb asphalt
using an infrared thermal imaging
camera. The temperature readings
recorded across the mat supported our
belief that there was far less variation
for LoCarb than hot mixed asphalt
and this is a key factor to achieving a
uniform density in the mat after final
compaction.”
The temperature profile measured by
Thermovision Services across the mat
behind the paver for HMA vs LoCarb.
There is also a significant reduction
in fumes and odours generated because
LoCarb is produced and placed
below the fuming temperature of
bitumen. Bitumen typically fumes at a
temperature around 135 degrees C and
the rate of fuming doubles with every
10 degree increase in temperature.
This helps improve the quality of air
for people living within the vicinity of
an asphalt plant and for the asphalt
workers placing LoCarb.
LoCarb Trials
Since the first trial section in 2006, Boral
has placed LoCarb on many streets
across Australia. In 2009 an extensive
trial was undertaken on the Deer Park
bypass with the properties of the mix
thoroughly evaluated. Further trial
sections of LoCarb were placed on the
Hume Highway in Melbourne in April
this year as part of the national Warm
Mix Asphalt validation project organised
by AAPA in conjunction with all the State
Road Authorities.
Laboratory tests carried out to date
have shown that the performance of
LoCarb is on par with that of hot mixed
asphalt. LoCarb technology is also very
versatile and can be applied to most
mixes from wearing course to base
courses.
On a recent job in Perth, 2000 tons of
LoCarb was placed on the Great Eastern
Highway as a patching material because
Main Roads Western Australia wanted a
mix that could be trafficked immediately
after it was placed and compacted.
Given the benefits to both the
environment and the road provider
there is a compelling argument that
LoCarb should be considered as an
asphalt material of first choice for your
next road project.
Plant LoCarb Hot mixed
asphalt
Asphalt temperature directly after mixing 138 172 34
Stack temperature 103 119 16
Paving Site
Asphalt temperature in the truck at site 105 137 37
Asphalt temperature behind the paver 90 116 26
difference
FULTON HOGAN PAVES
THE ROAD TO SUCCESS
Fulton Hogan, a Trans–Tasman leader in
the construction and asphalt industries
is using its Astec plant and equipment
as an advantage to build a multi-million
dollar road project in South Australia –
possibly the state’s largest.
To ensure that it was equipped to
deliver on the project’s tight product
specification and aggressive productivity
targets, Fulton Hogan engaged Astec
Australia to establish a modern asphalt
production facility and paving equipment
for the Northern Expressway Project
(NEXY)
The project is a 23 kilometre route that
will connect key areas of metropolitan
Adelaide and is considered a “benchmark
for modern road construction in
Australia”.
From the start, Astec Australia worked
in a partnering type relationship with
Fulton Hogan, to understand and provide
solutions for its exact project needs.
A few years ago Fulton Hogan used
Astec’s plant and equipment with great
success on its high profile Eastlink
Project in Victoria, so with those good
experiences fresh in its mind, Fulton
Hogan didn’t hesitate to engage Astec
in the supply of a T200 M Pack Double
Barrel Asphalt Plant, a SB1500 Material
Transfer Vehicle and a RP 190 Roadtec
Highway Paver.
Astec Australia provided a ‘turnkey’
solution for Fulton Hogan. Fulton Hogan
provided the hard stand area, gas and
power and Astec Australia did the rest.
Through its partnering arrangement with
Fulton Hogan, Astec constructed the civil
works for the plant site, and then used its
in house expertise to manufacture, ship,
install and commission the T200 Double
Barrel Asphalt Plant equipped with
Warm Mix and 50% RAP Technology.
To handle the project’s productivity
demands and the need for providing
various mix types on any given day,
Fulton Hogan opted for Astec’s Long
Term Storage Silos. Three 150 tonne silos
provide Fulton Hogan with the ability to
store 450 tonnes of hot mix for 72 hours
without loss of temperature or quality.
Fulton Hogan has used the storage
system to great advantage, increasing its
productivity through those short winter
Table 1
44 ROADS JUNE 2010/JULY 2010