View Q&A

TL-2 Concrete Barrier with No Reinforcement

Question
State	OH
Description Text	Ohio has issued an arbitrary five year phase out period for our older portable concrete barrier (not compliant to 350) ending as of January 1st, 2008. After that date, all of our unreinforced pin and loop barrier has to be off of projects. With the approaching date, all sorts of contractor questions have arisen, leading ODOT to review all remaining unreinforced barrier use and deciding on a case-by-case basis if the units really do have to be removed from pending projects. One final question is if our unreinforced barrier can be used for another year in a TL-2 urban situation. I know there is no FHWA mandate to remove the barrier, and it is ODOT's own arbitrary deadline, but do you believe unreinforced barrier would meet TL-2 criteria? Our 350 crash tested barrier has FHWA Acceptance letter B-93 (design is attached as rm42.pdf) and differs from the previous barrier design (attached as unreinforced 32 inch pcb.pdf) in only the internal rebar cage in lieu of the previous design's wire mesh. The pin and loop connection remained unchanged. I would be of the opinion that if the rebar cage reinforced barrier meets 350 TL-3, then the same design with the wire mesh would be crashworthy to TL-2. What do you think? Your answer will influence our decision to on whether or not to keep this particular barrier run in place for another year.

Question

State

Description Text

Ohio has issued an arbitrary five year phase out period for our older portable concrete barrier (not compliant to 350) ending as of January 1st, 2008. After that date, all of our unreinforced pin and loop barrier has to be off of projects.

With the approaching date, all sorts of contractor questions have arisen, leading ODOT to review all remaining unreinforced barrier use and deciding on a case-by-case basis if the units really do have to be removed from pending projects. One final question is if our unreinforced barrier can be used for another year in a TL-2 urban situation.

I know there is no FHWA mandate to remove the barrier, and it is ODOT's own arbitrary deadline, but do you believe unreinforced barrier would meet TL-2 criteria?

Our 350 crash tested barrier has FHWA Acceptance letter B-93 (design is attached as rm42.pdf) and differs from the previous barrier design (attached as unreinforced 32 inch pcb.pdf) in only the internal rebar cage in lieu of the previous design's wire mesh. The pin and loop connection remained unchanged.

I would be of the opinion that if the rebar cage reinforced barrier meets 350 TL-3, then the same design with the wire mesh would be crashworthy to TL-2. What do you think? Your answer will influence our decision to on whether or not to keep this particular barrier run in place for another year.

System Performance Evaluation

System Types
Portable Barriers

Applications

System Features

Date December 12, 2007
Previous Views (24) Favorites (0)

Attachment unreinforced 32 inch pcb.pdf Attachment rm42_oct06.pdf

Response
Response (active)	We have looked at the unreinforced barrier section that you sent. It appears that that design does have some reinforcement in the form of a wire mesh in the center of the barrier. The connection design of the barrier seems adequate. Because the design does have some minimal reinforcement, adequate connections, and the fact that the anticipated loads for a TL-2 urban installation will be much lower than the TL-3 impact loads, we believe that this barrier, as shown on the detail you submitted, should be adequate for use in TL-2 urban installations. One addition note on the detail is the tapered end section details. The TL-2 tested tapered end-section has been tested and required a 20' length. Thus, it appears the end section on your detail does not have sufficient length. We would recommend that you use an extended tapered end section if possible.

Response

Response
(active)

We have looked at the unreinforced barrier section that you sent. It appears that that design does have some reinforcement in the form of a wire mesh in the center of the barrier. The connection design of the barrier seems adequate. Because the design does have some minimal reinforcement, adequate connections, and the fact that the anticipated loads for a TL-2 urban installation will be much lower than the TL-3 impact loads, we believe that this barrier, as shown on the detail you submitted, should be adequate for use in TL-2 urban installations.

One addition note on the detail is the tapered end section details. The TL-2 tested tapered end-section has been tested and required a 20' length. Thus, it appears the end section on your detail does not have sufficient length. We would recommend that you use an extended tapered end section if possible.

Date December 12, 2007
Previous Views (24) Favorites (0)