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New Jersey Barrier Damage

Question
State SC
Description Text Here are some images of damage we saw while on a field trip. The details were our old Type 2 Jersey barrier with the glare screen
extension on the attached pages.

The glare screen retrofit is notorious for breaking off. I'm not sure why a monolithic detail was not created for that in our state, but we have
had numerous instances of those breaking.

One shot shows the repair patch that was done. I doubt dowles were used, so it is probably cold joints holding it in place.


Our 56" SS barrier height was first set by the overall dimension of this detail.
The SS barrier does have significantly more reinforcement in it, but it is thinner at the top than even the glare shield.

We have had several instances of damage to the Type 1 barrier detail as well. In most cases the damage did not extend into the base
portion like at this site. That barrier is only 6" at the top, but had nominal rebar in it.

The Jersey barriers are no longer standard, except for repairs or transitions to the new single slope standards.
Keywords
  • Permanent Concrete Barriers
Other Keywords none
Date April 14, 2020
Attachment NJ damage.zip
Attachment NJ_detail.png
Response
Response

Thanks for the photos.  It looks like the glare screen had minimal reinforcement, leaving it susceptible to heavy damage. A monolithic pour for the barrier and glare screen would have likely helped.  Utilizing full-height transverse steel stirrups would be even better.  I would not expect to see anywhere near this level of damage to Manitoba bridge rail or the 56” tall TL-5 barrier in SCDOT’s standards.

Date April 20, 2020
Response
Response

Yes, the glare shield is a poor design.  It was doweled into the top of the jersey barrier and contained 3 #3 bars horizontally.

 

Have you seen a glare shield retrofit for Jersey barriers that is more durable?  This would be helpful if we need to install new glare shield in locations where existing barrier is Jersey barrier.

 

 

The Jersey barrier was 12" thick at the top, 24" thick at the base, and in the impact shown in the attached image, the damage goes all the way to the ground.  

 

We have also seen instances with damage to the upper portion of the Jersey that goes down to the bottom slope.  Some of those cases again might have had 3 rows of #2 bars in that upper portion.

 

 

We agree that the new reinforcing will virtually eliminate this issue, but see that some states are detailing the barriers without reinforcing.

 

One major complaint from contractors is that the rebar is greatly affecting the slipforming process.  One asked about removing it entirely, another asked to remove just the vertical bars.  Caltrans indicates the vertical bars just at the expansion joints/ends of the wall, and contractors are trying to submit other state or tested details as alternates to our details.  Ultimately, our first project was built with rebar cages consistent with our standards, but the contractor did have some issues when the cage was not sufficiently secured before the slipforming operation.  In the Caltrans details, the vertical barriers are flipped from our details.  Do you know if they have had any construction issues with their rebar or barrier details?

 

We had an internal meeting last week to address some of the construction concerns that the contractors have raised, and likely will increase our barrier width by 4" (10" wide at top, 28" at bottom).  This hopefully will allow the rebar cage to fit better in the barrier.  The current main concern from the contractor was to use 4000 psi concrete, which will be allowed moving forward.

Date April 21, 2020
Attachment I385 Greenville 100615.JPG