Steel Exposed to Fire

[TRAK.Structural]

Looking for folks with experience evaluating steel structures that have been exposed to fire/heat. I've read some reference material/articles about general evaluation processes but its a bit of a mixed bag. Some say more or less that if it hasn't deformed than its generally ok. Others say that coupons should be taken for testing. Is there more recent info out there that is generally accepted that offers an evaluation procedure?

Additionally, when looking for deformation, is the standard of care just a visual inspection or are we talking about Lidar scanning to detect miniscule variations?

For reference, I've been asked if I want to evaluate a local auto body shop that had a recent fire. Its a couple bay PEMB structure so nothing super crazy.

 

[mfgenggear]

So based on this single data point, you're going to say that all foundations are immediately useless if any part of the superstructure suffers fire damage?

Lol you can lead a horse to water but ?
No however It practical experience.
And it prudent to test it. I am not concrete guy.
Do your own research
AI qoute
AI Overview


+7

To test concrete foundation strength after a house fire, visual inspection, sound tests, and rebound hammer tests can be used. Additionally, if possible, concrete samples should be extracted and tested in a laboratory for compressive strength.

Detailed Testing Methods:

1. 1. Visual Inspection:
   Look for signs like scorch marks, heat exposure, cracks, color changes (especially pinkish hues indicating chemical changes), surface spalling, and any signs of the foundation leaning or tilting, says JLC Online.
   
   
2. 2. Sound Tests:
   Strike various exposed surfaces with a hammer and listen for the sound. A hollow or brittle sound suggests damage, according to JLC Online.
   
   
3. 3. Rebound Hammer Test:
   This test measures the rebound of a spring-loaded mass after impacting the concrete surface. The rebound index is then used to estimate compressive strength, says ScienceDirect.com.
   
   
4. 4.Concrete Core Drilling:
   Extract concrete cores from the foundation using a drill. These cores can then be tested in a laboratory to determine their compressive strength, notes ConstructioNext.
   
   
5. 5.Laboratory Testing:
   If available, send samples of the concrete and reinforcing steel to a lab for further testing. This can help determine the depth of fire damage and the remaining strength of the materials, says Sandberg.
   

Important Considerations:

• Concrete that has been exposed to high temperatures can lose a significant amount of its strength, says ConstructioNext.
  
  
• Pinkish discoloration in concrete can indicate chemical changes due to high temperatures, says Home Improvement Stack Exchange.
  
  
• It's crucial to assess the depth of fire damage to determine the extent of the concrete's deterioration, notes ConstructioNext.
  
  
• If the concrete is significantly damaged, it may be necessary to excavate and replace the affected areas, says Remediation Group, Inc..

 

[phamENG]

So...you don't guarantee the foundation is destroyed?

 

[BN4537]

I do a significant amount of work with the local fire department. While a fire can damage a concrete foundation if it burns hot enough for long enough, it is extremely rare for that to happen. I have never seen locally a foundation that had to be removed/replaced/repaired because of a fire. Depends on the local concrete mixture at the time of the original pour, and what is in the building to contribute to fire load.

That said, we have a 4 minute response time here, so the firefighters are in position fighting the fire pretty quickly.

 

[mfgenggear]

I do a significant amount of work with the local fire department. While a fire can damage a concrete foundation if it burns hot enough for long enough, it is extremely rare for that to happen. I have never seen locally a foundation that had to be removed/replaced/repaired because of a fire. Depends on the local concrete mixture at the time of the original pour, and what is in the building to contribute to fire load.

That said, we have a 4 minute response time here, so the firefighters are in position fighting the fire pretty quickly.

every home in the cedar fire had failed and had to to be replace. physical inspection
compression strength was destroyed.
I not making thus stuff up.
now on the op post that appeared to be relative hot fire. some of the steel beams yielded. that is high temperture. unknown is what was source of fire. flammable liquids?
question here at what temperture it takes to
cause to have plastic deformation?
yes I garunty the concrete is compromised.
but it's up to the OP to determine that with factual testing with hard data. we could debate this. debate is Meaningless.
OP needs hard data to make a judgment.
and if pass or fails at least there is hard data
to make a judgment , correct?

 

[phamENG]

I not making thus stuff up.

Nobody said you were. But a bunch of houses in the middle of a nearly 300,000 acre fire are far from indicative of "normal" fire conditions.

now on the op post that appeared to be relative hot fire.

Well. Fires are hot. So I'll give you that.

some of the steel beams yielded.

Nowhere in the OP did they indicate anything had yielded. Based on the tone and wording, I'd bet TRAK hadn't even been to the site when that was posted. They were looking for suggestions on what to check and how to check it.

yes I garunty the concrete is compromised.

Again, we have zero information on the fire. It may have been in a trash can in the front office. Or it may have been in the waste oil tank. We don't know. So it's irresponsible to "guarantee" that the foundation has been compromised without more information. Want to suggest that they investigate the concrete's condition because of what could have happened? Great! But to say "I saw a few houses that were part of one of the worst conflagrations in recent history, so your fire certainly did the same kind of damage" lacks a certain rigor that should be expected of a practicing engineer.

 

[mfgenggear]

Nobody said you were. But a bunch of houses in the middle of a nearly 300,000 acre fire are far from indicative of "normal" fire conditions.


Well. Fires are hot. So I'll give you that.


Nowhere in the OP did they indicate anything had yielded. Based on the tone and wording, I'd bet TRAK hadn't even been to the site when that was posted. They were looking for suggestions on what to check and how to check it.


Again, we have zero information on the fire. It may have been in a trash can in the front office. Or it may have been in the waste oil tank. We don't know. So it's irresponsible to "guarantee" that the foundation has been compromised without more information. Want to suggest that they investigate the concrete's condition because of what could have happened? Great! But to say "I saw a few houses that were part of one of the worst conflagrations in recent history, so your fire certainly did the same kind of damage" lacks a certain rigor that should be expected of a practicing engineer.

The 2003 Cedar Fire, which was the largest and most destructive wildfire in California's history at the time, destroyed 2,232 homes. In total, the fire destroyed 2,820 buildings, including 2,232 homes, 22 commercial buildings, and 566 outbuildings. The Cedar Fire also killed 15 people and burned over 280,000 acres.

 

[mfgenggear]

Nobody said you were. But a bunch of houses in the middle of a nearly 300,000 acre fire are far from indicative of "normal" fire conditions.


Well. Fires are hot. So I'll give you that.


Nowhere in the OP did they indicate anything had yielded. Based on the tone and wording, I'd bet TRAK hadn't even been to the site when that was posted. They were looking for suggestions on what to check and how to check it.


Again, we have zero information on the fire. It may have been in a trash can in the front office. Or it may have been in the waste oil tank. We don't know. So it's irresponsible to "guarantee" that the foundation has been compromised without more information. Want to suggest that they investigate the concrete's condition because of what could have happened? Great! But to say "I saw a few houses that were part of one of the worst conflagrations in recent history, so your fire certainly did the same kind of damage" lacks a certain rigor that should be expected of a practicing engineer.

again debate is meaning less

 

[BN4537]

every home in the cedar fire had failed and had to to be replace. physical inspection
compression strength was destroyed.
I not making thus stuff up.

I believe you.

OP needs hard data to make a judgment.

and if pass or fails at least there is hard data
to make a judgment , correct?

Yes, the concrete should be checked.

 

[phamENG]

he 2003 Cedar Fire, which was the largest and most destructive wildfire in California's history at the time, destroyed 2,232 homes. In total, the fire destroyed 2,820 buildings, including 2,232 homes, 22 commercial buildings, and 566 outbuildings. The Cedar Fire also killed 15 people and burned over 280,000 acres.

Thanks for proving my point?

again debate is meaning less

If only there were a debate; this would be a lot more interesting.

 

[gte447f]

Lol you can lead a horse to water but ?
No however It practical experience.
And it prudent to test it. I am not concrete guy.
Do your own research
AI qoute
AI Overview
View attachment 8965
View attachment 8964
+7

To test concrete foundation strength after a house fire, visual inspection, sound tests, and rebound hammer tests can be used. Additionally, if possible, concrete samples should be extracted and tested in a laboratory for compressive strength.

Detailed Testing Methods:

1. 1. Visual Inspection:
   Look for signs like scorch marks, heat exposure, cracks, color changes (especially pinkish hues indicating chemical changes), surface spalling, and any signs of the foundation leaning or tilting, says JLC Online.
   
   
2. 2. Sound Tests:
   Strike various exposed surfaces with a hammer and listen for the sound. A hollow or brittle sound suggests damage, according to JLC Online.
   
   
3. 3. Rebound Hammer Test:
   This test measures the rebound of a spring-loaded mass after impacting the concrete surface. The rebound index is then used to estimate compressive strength, says ScienceDirect.com.
   
   
4. 4.Concrete Core Drilling:
   Extract concrete cores from the foundation using a drill. These cores can then be tested in a laboratory to determine their compressive strength, notes ConstructioNext.
   
   
5. 5.Laboratory Testing:
   If available, send samples of the concrete and reinforcing steel to a lab for further testing. This can help determine the depth of fire damage and the remaining strength of the materials, says Sandberg.

Important Considerations:

• Concrete that has been exposed to high temperatures can lose a significant amount of its strength, says ConstructioNext.
  
  
• Pinkish discoloration in concrete can indicate chemical changes due to high temperatures, says Home Improvement Stack Exchange.
  
  
• It's crucial to assess the depth of fire damage to determine the extent of the concrete's deterioration, notes ConstructioNext.
  
  
• If the concrete is significantly damaged, it may be necessary to excavate and replace the affected areas, says Remediation Group, Inc..

Well @phamENG is a concrete guy, in that they are a structural engineer who has studied concrete as a building material and probably designed lots of concrete building elements, so you aren't telling them anything they don't already know with this AI BS.

 

[mfgenggear]

Well @phamENG is a concrete guy, in that they are a structural engineer who has studied concrete as a building material and probably designed lots of concrete building elements, so you aren't telling them anything they don't already know with this AI BS.

Well he could have said that instead of attacking me. This was actually observation fron actual homes destroyed in that fire. 100% of those homes failed is a fact. Not some theory.
That was why I made that comment. Actual observed failed concrete. Now I am ready to move on . End of discussion.

 

[ANE91]

I find fire-damaged concrete comparatively more fun to evaluate. I’ve probably done more of that than for steel buildings. I’m sure @TRAK.Structural will report back with any concrete question marks. We can whip ourselves up into a frenzy, then.