SUPERPAVE Digest 449
Topics covered in this issue include:
2) a question to the group from a new member
by Clair LaVaye <>
3) Re: a question to the group from a new member
by "Ervin Dukatz" <>
- To:
- Subject: a question to the group from a new member
- From: Clair LaVaye <
- Date: Tue, 27 Feb 2001 15:31:35 -0800
Hi Superpave List Newsgroup Members,
A new list member wanted a question to go to the group. I have added
him to the List so that he can hear your reply via the group, but
below you will find his question for you.
Thanks,
Clair
Superpave ListMom
FROM: Farhad Zarinejad <>
QUESTION:
At present, I am associated with construction engineering of a major
Superpave project, and have not
been able to convince the contractor to achieve the required density
within Breakdown and Intermediate
stages. In brief, I am trying to refrain him of utilizing his
vibratory roller, while the mat temperature drops below 200F.
Thank you in advance,
Farhad
______
Clair LaVaye
Website Administrator
Center for Transportation Research
University of Texas at Austin
- To: <
- Subject: Re: a question to the group from a new member
- From: "Ervin Dukatz" <
- Date: Tue, 27 Feb 2001 17:01:42 -0600
We have achieved density with the cold roller on some of our Superpave jobs, both warranty and state QMP projects, at temperatures as low as 110F. The rolling was carefully monitored by both contractor and state inspectors to achieved the desired level of compaction. At temperatures between 140 to 200 F the mix was too tender to roll. The temperature induced tenderness appears to be thixotropic as the next day and the rest of the summer when pavement temperatures reached well over 120F, the pavements did not shove or rut.
Erv Dukatz
Mathy Constuction/MTE Laboratory
SUPERPAVE Digest 450
Topics covered in this issue include:
1) RE: a question to the group from a new member
by "Steven Jackson"
- To: <
- Subject: RE: a question to the group from a new member
- From: "Steven Jackson" <
- Date: Wed, 28 Feb 2001 08:31:17 -0600
It has been our experience that vibratory compactors do very well in
breakdown and intermediate compaction. However to achieve density we have to
use a static 20 ton roller and a rubber tire roller when the mat gets below
200( F. We have used a vibratory roller under 200( F on some jobs. We have
found that what works for one job most likely wont work on the next. I would
not try to prohibit a contractor from using a particular roller on a job. If
there are penalties for density or smoothness they will find out very
quickly what works and what doesn't work. If you suspect a problem monitor
the mat edges to see if they are walking, look for waves in the mat, and
look for broken rock in the cores.
Steve Jackson