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Illinois Temporary Concrete Barrier

Question
State WI
Description Text

Please review the attached details from Illinois. Would this barrier be acceptable in Wisconsin? I presume it is approved for use by FHWA.

 

The Illinois barrier does not meet the requirements of WisDOT S.D.D.s. I did a cursory review of the details and compared the details for both states. There are some differences as I outline below:

 

Overall dimensions are the same.       

The location of the loop bars are different vertically.

Anchor locations are different.

Anchor hole size is different.

Dimensions and shape of the connecting loop bars are different.

Steel anchor stakes are different is size and shape.

Illinois shows no provision for anchoring to a bridge deck or pavement.

 

These are a few of the issues I spotted quickly.

 

If the Illinois barrier is acceptable, the field staff would be required to write a CCO in order to incorporate the details into their contracts. The two barriers could not be intermixed.

 

Please provide some guidance as to the use of the Illinois concrete  barrier. The staff on the USH 41 projects are trying to be proactive in case this barrier does show up in this area. I don't know how the N-S Freeway is handling this situation.

Keywords
  • Temporary Barriers
Other Keywords none
Date March 31, 2010
Attachment b171.pdf


Response
Response

I have reviewed the Illinois barrier detail you sent. We believe that the design will be okay for free standing applications. The design is basically the MwRSF F-shape with the Oregon connection. A few additional comments:

 

  1. Oregon barrier and connection loops and pin were tested to 350, thus the connection should not be an issue.
  2. There is a small difference in barrier connection gap between the Illinois detail and the Oregon design (1" for Oregon vs. 2" for Illinois), but this should not be a big issue. It may produce larger barrier deflections than the tested Oregon design, but would be comparable with the MwRSF F-shape. The Oregon barrier achieves its low dynamic deflections largely due to the reduction of the barrier gap.
  3. Oregon barrier has more moment capacity (more longitudinal steel, farther to outside), but MwRSF barrier has met MASH with current reinforcement.
  4. Longitudinal steel is placed farther out in the toe of barrier in Oregon design, but again should not be an issue. It may lead to higher deflections if toes fracture. This hasn't been a problem with MwRSF F-shape barrier testing.
  5. The tie-downs systems developed to pass through the toe of the barrier will not fit in current Illinois barrier design. Thus, we do not recommend using the tie-down systems with the Illinois barrier.

 

FHWA approved a Colorado barrier that was very similar to the Illinois barrier design. The only real difference was the steel reinforcement which was setup to match the Oregon detail rather than the MwRSF barrier. See attached.

 

The difference in reinforcing steel is not a big issue as the MwRSF barrier has met MASH with current reinforcement.

 

The tie-down anchorage for this is very different than the MwRSF barrier.

 

Again, we would be hesitant to apply the MwRSF tie-down anchor systems with the Illinois barrier as detailed, but believe it should be acceptable in a free-standing configuration.

Date April 2, 2010


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