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.

Students Click Here

Old clay tile and concrete beam floor cracks

Old clay tile and concrete beam floor cracks

Old clay tile and concrete beam floor cracks

We have a floor that experienced the attached cracks. It is a 100 year old clay tile system where they used 8" tile and 2" of topping which created the 10" total depth concrete T-beams as shown on the joist load table diagram on the attached file. The T-beams are spaced at 17" on center and are about 5 inches thick at the bottom. The T-beams have the attached reinforcing at the bottom and top at the ends on the attached original drawing I recently found.

The bottom of the floor did not show any damage from overloading in any areas, only some rust damage. They drilled a couple of locations in the top of the slab and the cracks went an inch or a slightly more deep, but I can't say for sure the cracks don't extend down below the topping and into the beams at some locations. The cracks are not something that have been there for years. These appear to be yield line type cracks but the pattern does not meet what I would have expected for a one-way slab, unless the top temperature bars altered the yield lines? Also, there was no spalling off of the top concrete from compression that I am aware of and none of the bottom of the beams were cracked. There is an adjacent existing room that have similar but old topping cracks that have been worn down from rolling cart traffic. Any thoughts on the attached crack patterns?

RE: Old clay tile and concrete beam floor cracks

The attached was also in the incomplete existing drawing set, but I believe it was either meant to apply typically to another area or is incorrectly shown since the temperature bars should be up in the topping and not down running into the adjacent clay tiles.

RE: Old clay tile and concrete beam floor cracks

The column grid looks pretty square. It may have been designed as a 1-way slab, but the geometry may be forcing it to act more like a 2-way slab despite the light reinforcing in the transverse direction.

Am I correct in assuming the second picture (with 3 cracks coming together) is in the corner bay? May be a trick of the lighting, but it looks like you have a relative vertical displacement across the crack, which could suggest cracking caused by upward deflection due to a (very) imbalanced load across the bays. It does look surprisingly like a yield line failure analysis model.

RE: Old clay tile and concrete beam floor cracks

I unfortunately did not take these pictures and can't say for sure, they were taken during the repair process but I believe you are correct. Here is another one where you see the cracks have extended further than the cracks that were drawn on the previous attached diagram months ago.

That was my idea as well, the topping slab and temperature reinforcing creating two-way slab behavior in the transverse direction to the T-beams.

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! Already a Member? Login


eBook - Functional Prototyping Using Metal 3D Printing
Functional prototypes are a key step in product development – they give engineers a chance to test new ideas and designs while also revealing how the product will stand up to real-world use. And when it comes to functional prototypes, 3D printing is rewriting the rules of what’s possible. Download Now

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