Concete repair strengths 2

[Candia]

I have a few questions relating to concrete .
A friend suggested I try this site so I'm hoping I can get some help in this.Based on a typical elevated structural concrete slab in a office tower 9" thick , I have the following questions.
1 - what is the strength ( average) ?
2 - what is required fire rating ?
Now the next ? Are based on repairing a core hole 5" diameter.
If the hole is plated from below , rebar dowels installed and filled intirely with non shrink grout .
What will the patch strength be?
What will fire rating be on patch?
The final ? Is based on a bad repair.
5" hole filled with pink insulation with 1" of non shrink grout applied to top.
No rebar.
I'm looking for strength and fire rating comparison
Of three scenarios of a elevated floor.
1 being original slab
2 being a hole repair done properly
3 being a contractor doing a bad repair
Help is greatly appreciated

 

[dicksewerrat]

You should probably look in the yellow pages for a structural engineer.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[bridgebuster]

dick - I second the motion.

 

[msquared48]

I third it. Plus this probably a PT slab at 9"


Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[Candia]

It's just a question to get a rough
Idea of slab strengths of the 3 conditions

 

[msquared48]

The strength of the slab depends on the type of construction as well as the loading conditions. You really do need a local SE to help you.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[Candia]

Generic numbers would be fine.
It's not geographically important.
Could even be based on lab conditions.
I'm looking for a rough variable between
The three scenarios.

 

[JAE]

Fire rating, assuming that the holes are filled with cementitious materials, should be the same as the original slab.

You asked about "strength". That is way too general of a term. There are multiple meanings of the word strength and we can't
respond to that sort of question as it is too vague. Strength of the material? Strength of the bond at the hole? Strength of the plug to withstand
an applied point load? Strength change in the slab's flexural capacity due to the hole? etc. etc.

 

[Candia]

Thanks for the responses.
I think I'll hire a local engineer to give me test results

 

[Ron]

Candia...best engineering decision you've made today!

 

[Candia]

Thanks