SUPERPAVE Digest 161
Topics covered in this issue include:
1) Re: forwarding a message intended for the group: Subject: superpave
in suburban developments
by Stephen Goodman <sgoodman@tac-atc.ca>
2) Wrong Internet URL
by Stephen Goodman <sgoodman@tac-atc.ca>
3) RE Superpave in subdivisions
by "Vincent M.Egan" <hypac@rmi.net>
Dear Clair and Fellow Superpave Group Members,
In regard to the question of compacting Superpave mixes without the use of
vibration, there actually is a compactor that has been shown to compact both
stiff and tender mixes without vibration. In fact, this compactor takes the
place of both a conventional steel drum roller and a pneumatic roller.
The compactor is called the HIPAC and is being developed in Australia by
Pioneer Road Services Ltd. Numerous papers have been presented on this device
based on trials in Canada and Australia. Although the HIPAC is not yet in full
production, Pioneer is planning to send units to Canada and the US for
additional testing. Representatives from the US Army Corps of Engineers
recently visited Pioneer in Australia to see the HIPAC in action. Mr. Ian
Rickards, National Technical Manager at Pioneer presented a paper at this
year's TRB conference and afterward, met with representatives at Heritage
Research to further discuss bringing the HIPAC to the US.
Without boring you to tears with the details, the HIPAC efficiently compacts
asphalt using two modules containing multiple small drums surrounded by a
rubber belt. The belt forms a "rolling flat plate" that applies a small
contact pressure over a long period of time. Due to the viscoelastic nature of
asphalt, the application of a small load over a longer period of time produces
the same (if not better) results as a shorter, more intense load. Conclusive
field results show equal densities with less passes and less variation in
density with the HIPAC.
If you would like more information regarding the HIPAC, you can contact Mr.
Rickards through the Pioneer website at www.prs.com.au or visit the Centre for
Advanced Asphalt Research and Technology at Carleton University at
www.civeng.carleton.ca/CAART/main/hipac.htm.
Sincerely,
Steve Goodman, B.A.Sc., E.I.T.
Research Associate
Canadian Strategic Highway Research Program (C-SHRP)
Transportation Association of Canada (TAC)
2323 St. Laurent Blvd., Ottawa, Ontario, Canada K1G 4J8
Tele: (613) 736-1350
Fax: (613) 736-1395
email: sgoodman@tac-atc.ca
Clair LaVaye wrote:
> Hi Superpave Newsgroup members,
>
> I am forwarding on this question to the group. It was mailed to me instead
> of the group, so I am forwarding it on. I am not sure if Bob ever got this
> message through to the rest of you:
>
> Subject: superpave in suburban developemants
> Date: Fri, 12 Mar 1999 19:31:59 -0800
> MIME-Version: 1.0
> Status:
>
> I have a question regarding the use of superpave mixes in housing
> developements. In the past we have had complaints about using vibratory
> rollers, due to the vibrations being felt in the walls of existing homes.
> Using superpave would require more use of vibratory rollers than ever
> before, yet the state is mandating the use of superpave and trying to avoid
> responsibility for any problems by saying that we can compact the mix any
> way we want.ore they are not forcing us to use vibratory rollers. Is there
> another method of achieving compaction with superpave mixes besides a
> vibratory roller, does any one have any thoughts on this? Thanks so much
> for your help!
>
> Bob Weber
> Christiana Materials
> "Christiana Materials, Inc." <cmihm@inet.net>
--
My apologies folks,
The website address for the Centre for Advanced Asphalt Research and
Technology (CAART) is as follows:
http://civeng.carleton.ca/CAART
Make sure that CAART is in capital letters. The HIPAC information can
be found in the "Current Research" section of the site. Those with keen
eyes will notice that I am a member of CAART in addition to working at
C-SHRP so I should make it clear that my work at CAART is completely
unrelated to my work at C-SHRP.
Sincerely,
Steve Goodman, B.A.Sc., E.I.T.
Research Associate
Canadian Strategic Highway Research Program (C-SHRP)
Transportation Association of Canada (TAC)
2323 St. Laurent Blvd., Ottawa, Ontario, Canada K1G 4J8
Tele: (613) 736-1350
Fax: (613) 736-1395
email: sgoodman@tac-atc.ca
Why would one want to use a Superpave designed mix in a subdivision. One
of the components of a "Superpave" designed mix, if there is such an animal,
is an ESAL requirement to reduce the rutting associated with more dense
graded mixes that may be unable to handle high volume traffic loads. Last
time I looked most subdivisions have made provisions to control high axle
load truck traffic by allowing the DOT to build; highways!!!
While a "Superpave" or PG binder may create some Compaction problem's
it is the gradations that make the most of it. A good dense graded with
a PG binder should compact quite well with a 12 1/2 ton pneumatic and
a 10-14 ton static roller or some combination of the above. Vibratory
penetration is a very real issue and I would be willing to bet there is
not a subdivision out there that has created base to carry highway ESALS.
This is another incidence of a little bit is good a lot must be better.
If one was to use a static-rubber-static roller train and watched the
TEMPERATURE of the mix as it was compacted density should roll right in
there. The next question is: If they are requiring, a "Superpave" mix and there
ain't no such animal, then are they using a gyratory or trying to bastardize
this "Superpave" mix under Marshall Law.
Look carefully at the binder and see if it an unmodified AC-20 can fill
the bill. And what is the ratio of lift thickness to top size aggregate.
General rule of thumb is never to vibrate any material that does not have
at least a 2.5:1 top size ratio.
If one needs to use a vibratory because of job designed constraints perhaps
a smaller, i.e. 3-5 ton, vibratory would work with minimal risk of vibe
penetration and home damage. I wonder if the design team has thought this through for if the subsurface
product allows that much vibe travel it is probably too soft. And what
about underground utilities such as sewer pipe and water. "Superpave" designed mixes have a place and it is not in low traffic areas.
Vincent M. Egan
District Sales Manager
Compaction America
hypac@rmi.net
602.418.6404 mobile
800.344.5985 ext #2314 voice mail
========================================
From: Superpave Technology <superpave@mcfeeley.cc.utexas.edu>
To: Internet Mail::[Superpave Technology <superpave@mcfeeley.cc.utexas.edu>]
Subject: SUPERPAVE digest 159
Date: 3/13/99 1:23 AM
SUPERPAVE Digest 159
Topics covered in this issue include:
1) Flushing 2 -Reply
by Ronald Sines <RSINES@gw.dot.state.ny.us>
2) forwarding a message intended for the group: Subject: superpave
in suburban developments
by Clair LaVaye <clair@mail.utexas.edu>
