Carbon Fiber Wrapping to repair corroded steel structures

[SIMONMAGSUCANG]

Hi all,

I need to repair the angle steel and I-Beam which are heavily corroded plus metal loss, it is for overhead pipe rack, this is an old LNG plant where these steel structures had never been changed since the last 25 years. I'm currently looking at repairing these steel structure by using Carbon Fiber Wrap; I know this method has been widely used but I just couldn't find any calculation to support my proposal, can anyone here help?

I am familiar with PCC-2 but it is for pipes, not steel structures.

 

[bimr]

You should post this in the structural forum for the best results.

One would think that you would have to have a structural prepare the calculations for you.

The repairs outlined in PCC-2 are for non-hazardous applications. Hard to see how repairs to a piperack in a LNG plant would be considered non-hazardous. Pipe supports in plants handling flammables are generally constructed from concrete.

 

[SIMONMAGSUCANG]

You are right, perhaps I should post this in civil structural forum.

Need help urgently..

 

[IFRs]

If the location allows, add new foundations and pipe supports in between the existing, then demo the existing. This may seem more expensive but in the long rung I think you will be happier.

 

[SIMONMAGSUCANG]

There is no extra space for additional supports to be added.. the area is too congested, even replacing with new steel structure is a huge challenge and therefore I am looking at any reinforcement method which I expect using carbon fiber wrapping will help and get rid of al the hustles..

 

[BigInch]

Corrosion Forum might be even better.

 

[SIMONMAGSUCANG]

Thanks guys. I am already receiving some feedback and replies in the other forum as per advice. Thank you for your kind attention.

 

[ewh]

I am glad that you are receiving the assistance you need, but please try to refrain from double (triple) posting.

"Know the rules well, so you can break them effectively."
-Dalai Lama XIV

 

[EdStainless]

Typically they use fiberglass, not carbon because of galvanic corrosion concerns.
You might do some research into earthquake remediation, and this is common there.
This is a very labor intensive process, much more work than building steel structures.
And they will be almost impossible to repair or modify in the future.
I would see this as a last option.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[SIMONMAGSUCANG]

hi Edstainless, I am actually considering Carbon Fiber Reinforced Polymer. Had spoken to a few manufacturer, since Carbon Fiber has much stronger strength than normal Fiberglass, I will managed to save some cost here, for example same application I might need 8 layers of fiberglass than 4 layers of carbon fiber. also, yes it will be labour intense to go for 8 layers of fiberglass but eventually it is not so with 4 layers carbon fiber.

Ya, it will make it unable to be opened up for repair and maintenance, even inspection I will need something intense to do so..

 

[3DDave]

Would like to see a picture. This would serve as an example of a poor maintainability design.

 

[Compositepro]

Actually, the tensile strength of fiberglass is about the same as standard modulus, PAN-based carbon fiber (500,000 psi).
It is the Young's modulus (stiffness) of carbon that is significantly higher (30+ msi versus 10 msi). Matching stiffness is important to sharing load properly.

 

[SIMONMAGSUCANG]

Hi Compositepro, does this mean you recommend tp use fiberglass than carbon steel?

 

[Compositepro]

No, I'm just correcting the comment about comparative strength. My other comment comment about stiffness of carbon is why you would want to use carbon to repair steel. Galvanic corrosion concerns can be addressed by using a ply of glass fabric before applying carbon fabrics. This all gets very complicated very quickly, which is why you should consult an experienced contractor.

 

[SIMONMAGSUCANG]

according to manufacturer, there will be a layer of epoxy base corrosion inhibitor to be coated on the surface after surface preparation, thickness about 20 mils, after the coating becomes touch dry the carbon fiber can be put on..