Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Identify Structural Framing system 3

Status
Not open for further replies.

JStructsteel

Structural
Joined
Aug 22, 2002
Messages
1,470
Location
US
Looked at a building earlier this week with a structural Terra Cotta floor system (for lack of better term). its make up of reinforced concrete joists, beams and Terra Cotta system between to make up the floor slab or form to pour the slab.

Its in bad shape. I cant find alot of info on the system. From the looks of it, it almost looks like a bar joist encased in concrete in some areas.

Any idea how to even evaluate (in my mind most 'joists' have failed, and its luck holding up most of the building) I raised quite an alarm about the building, i dont see it as a safe building.

IMG_1019_bfkknk.jpg
IMG_1037_csmfk3.jpg
IMG_1046_v8njoo.jpg
 
I though I've seen most of the floor systems, but WOW!
 
Yeah, it looks bad.
It seems like you're not familiar with the system, is that right? It's a relatively common system where I'm from.
I don't really understand what's bothering you, could you elaborate?
 
JStructsteel said:
I cant find a lot of info on the system. From the looks of it, it almost looks like a bar joist encased in concrete in some areas.

Looks like a one-way clay tile joist system, possibly Natcoflor's system.

Matthew Stuart's Structure magazine series entitled Antiquated Structural System - Part 3 (March 2008) covers it somewhat.

natcoflor_spp74c.png


See attached file for a copy of the paper or go to this Link for a free download.
 
It used to be common here but with masonry rather than terracotta. Known as beam and block flooring - or pot and plank flooring.

 

I am not familiar with the system, I would like more information.

Hopefully you are being facetious about the issues.

I was hoping to get more information so I can fully report my findings, and solutions.

It looks loke Inginuity has posted some information, thank you.
 
OP said:
Hopefully you are being facetious about the issues.
I meant to say something else, but I guess I didn't really express it well in english :) It's obvious that it's in a bad shape and unsafe.
Ingenuity probably answered your questions because that's how it's obviously done in the US. I'll just add few of my insights and how the modern version is done (where I'm from at least). Maybe it'll give you some ideas how to repair it.
I don't know if this will help you at all.

Back here we usually provide a mesh above the bricks and pour 5-6 cm of concrete on top. Perpendicular to the joists we put RC "bond" beams at every 3 meters to distribute the loads better (without them any point or line load is taken by just one joist). It's also usually not done with formwork like in your case, but with special masonry elements, which come with a small vertical triangular truss and usually prestressed longitudinal reinforcement. The system is usually considered to be a series of simply supported beams (as ingenuity mentioned it spans one way, paralel to the reinforcement), but it seems like in the US you provide some top reinforcement so I guess it's continuous.
Bricks (or terracota) don't really matter for the load bearing capacity.
Also, today we usually change the span direction between floors to ensure that walls in both directions are (relatively) equally loaded. I doubt that this is done here, since a lot of old systems don't care about lateral loads but it might not be a bad idea to check if you plan to remove some elements. Be sure to check how the non-loadbearing walls are constructed (keep in mind that I don't know anything about the US practices, I'm talking from a european experience). They can either be constructed between the floors (they rest on a floor) or they could be constructed continuous (you stop the floor at the nonbearing wall).
 
If there are transverse beams that are in good shape, as well as the beam end supports, you might be able to restore the floor to support light uses.

image_gwamip.png
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top