INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Jobs

FRP over an existing plastered wall?

FRP over an existing plastered wall?

(OP)
Hello community,

I have an existing 1940's concrete frame system with infill brick for the entire elevation(two leaf with a 25mm air gap in between). I am considering installing FRP at the base floor to halt potential soft-story effects when the infill fails . The issue is that there is an existing cement plaster render on both sides of the infilled frame. My question is what do you think of installing FRP over the plaster rather than chipping out all the plaster where this will go? I think applyying FRP to the existing brick is always ideal but in terms of shear transfer, im sure i can transfer shear forces from the conc frame to the FRP, the plaster is only bracing the FRP. Thoughts?

RE: FRP over an existing plastered wall?

How would the shear forces from the concrete frame get to the FRP if you don't attach it directly to the frame. Without designing the plaster to transfer the loads I would shy away from that.

RE: FRP over an existing plastered wall?

You would be depending on two bonded interfaces rather than one. FRP to plaster, and plaster to brick. Perhaps you need to do some testing of the existing plaster to brick bond to assure yourself that it is strong enough. Seismic retrofitting always depends as much on judgment as on analysis, but I would want to be satisfied that the plaster is sound and well adhered.

RE: FRP over an existing plastered wall?

(OP)
I appreciate the feedback. You are all echo-ing my thoughts. Cheers.
I'm just going to have blow out the plaster and install FRP, I can sleep better that way.

RE: FRP over an existing plastered wall?

(OP)
I appreciate the feedback. You are all echo-ing my thoughts. Cheers.
I'm just going to have blow out the plaster and install FRP, I can sleep better that way.

RE: FRP over an existing plastered wall?

Have you considered blowing out the plaster and bricks, and infilling with reinforced concrete? In my area, FRP is an expensive alternative.

RE: FRP over an existing plastered wall?

(OP)
wannabeSE,
Actually my situation is a bit unique in that my client's property is half of an existing structure. If I stiffen up the elevation in the way you are talking about, then i am introducing eccentricity in a big way because i have ability to equally stiffen up the elevation on the neighbor's side of the building. I am only trying to introduce ductility into the existing system rather than stiffen it up and have it attract more load (it's founded on a rock, so ground has stiff period already).

RE: FRP over an existing plastered wall?

(OP)
oops, missed a word: ...I don't have the bility to equally stiffen...

RE: FRP over an existing plastered wall?

Did you check your plaster for asbestos? May not be an issue... it was often used as a binder for plaster at that time period.

Dik

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close