Carbon fiber to strengthen bridge panel 1

[AAEC]

Has anyone experience installing this carbone fiber made by Fortress Stabilization Systems? This carbon fiber is to help strengthen existing concrete. I have this bridge rehabilitation project that this carbon fiber maybe of good use to save the bridge from being replace.

 

[Qshake]

Carbon fiber is a good product for bridge strengthening but only a few projects have actually be accomplished so far. Mainly because this material behavior is complex and hasn't been around in the civil infrastructure as it has in aerospace applications.

Right now ACI has a publication on the use of Carbon fiber matrices or Carbon Fiber Reinforced Polymeres CFRPs along with Glass and other types of fibers. There is a movement to have AASHTO adopt much of the language of ACI but then that was dropped at the last AASHTO bridge subcommittee meeting.

As a result there is an application out there but know one really knows how to use it properly or design it properly (except a few engineers and researchers and vendors) and no guide specification for the engineer to use.

When there is no guide spec, it's hard for the engineer to take on a project like this as he assumes to much liability for the design and performance of a product he can't show what really is the standard of care for the industry.

There are tons of papers for strengthening concrete beams for flexure, shear and torsion. Check out ASCE's Journal for Composites in Construction. ACI journals are also packed wiht good information.

Good luck.

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.

 

[Ron]

Agree with Qshake. I've used Carbon Fiber (Sika) for correction of deficiencies in a people mover project. Worked well and has now been in place for about 13 years....seems to be performing well; however, the frequency of loading for a people mover system is not as high as bridge loading.

 

[bridgebuster]

Attached is NCHRP Report 514 which discusses FRP repairs. Our office did a carbon-wrap project about 5 or 6 years ago. It involved strengthening fur pier caps. R.J. Watson Company ( I believe they merged with another firm and operate under a new name) was the designer, supplier, and installer.

 

[AAEC]

Thank you all for your answers. I have this contractor that will provide me examples of his work and more information about the product. The contractor do design and build project. Will see what they have. Will try to get you update.

 

[Qshake]

AAEC - Be mindful of contractors who want to do the CFRP work themselves. The work is tricky and it's best to have a certified FRP company do the work. So if you go this route with a prime contractor, you'll want to make sure the specifications call for x number of years experience with certain products and must have at least y projects completed successfully.

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.

 

[wiktor]

I do not have experience with Fortress, but I was involved design and specify CF strenghtening of the large concrete wall in NYC, where R.J. Watson was a supplier of fiber material.
The design is based on the similar principles as typical design of the reiforced concrete, the only difference being position of the reinforcement and higher Young modulus than for typical steel.
Key issue is proper bonding of the FRP to the concrete, and in the qouted case 1/2" dia drilled epoxied fiber inserts were used.
Specification for FRP iis attached.
Regards
Wiktor

 

[BRGENG]

Many, many bridges have been fixed with this system if you know where to look. I have designed several bridge repairs with carbon fiber and just completed a project that had several girders damaged by a dump truck. Each girder had at least 2 prestressed strands snapped.

If you want assistance contact the Civil Engineering Department at Missouri Science and Technology in Rolla, MO. They have been doing research for years on Carbon Fiber and are behind the proposed ACI code for it.

Agree with the posts above, you have to watch the contractor on this and inspect all work. One misstep and your results will not be what you designed.