April 8, 2026

246 - Fire Fundamentals pt. 20 - Fire Resistance Criteria with Piotr Turkowski

246 - Fire Fundamentals pt. 20 - Fire Resistance Criteria with Piotr Turkowski
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246 - Fire Fundamentals pt. 20 - Fire Resistance Criteria with Piotr Turkowski
246 - Fire Fundamentals pt. 20 - Fire Resistance Criteria with Piotr Turkowski
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In this episode of fire fundamentals with the ITB fire resistance expert Piotr Turkowski we break down what a fire resistance rating criteria, and what the letters behind ratings like “REI 60” exactly stand for. We use lab experience to explain where the standards are clear, where they are oddly traditional, and where comparisons between products can mislead.

• ISO definition of fire resistance as an ability over time
• What R E I W and M mean in fire resistance classification
• Load bearing capacity as deformation and collapse criteria
• How test loads are applied and why load choice matters
• Integrity E as flames and openings rather than smoke tightness
• Cotton pad test and why it blurs integrity versus insulation
• Insulation I temperature rise limits and prescribed thermocouple points
• Radiation W as a heat flux limit and when it matters
• Mechanical impact M and the wrecking ball style verification
• Why fire resistance time does not add up across layers
• Furnace minutes, strict thresholds, and unknown test uncertainty

If you liked this podcast episode, you will definietely enjoy:


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The Fire Science Show is produced by the Fire Science Media in collaboration with OFR Consultants. Thank you to the podcast sponsor for their continuous support towards our mission.

00:00 - Why Fire Resistance Still Confuses

04:40 - A Working Definition Of Fire Resistance

07:40 - R Criteria And Deformation Limits

16:10 - How Test Loads Get Chosen

25:00 - Integrity E Flames Cracks Cotton

30:53 - Insulation I Temperatures And Thermocouples

40:50 - Radiation W And What It Adds

44:58 - Mechanical Impact M Wrecking Ball Test

50:45 - Why Ratings Do Not Add Up

55:30 - The Clock Rules And Uncertainty

58:37 - Key Takeaways And What Comes Next

WEBVTT

00:00:06.080 --> 00:00:06.290
​Hello everybody.

00:00:06.290 --> 00:00:07.549
Welcome to the Fire Science Show.

00:00:07.549 --> 00:00:11.448
Last week we had a little laugh, uh, with the April Fools.

00:00:11.448 --> 00:00:21.483
it appears that when you have a podcast on Wednesdays, it's that easy to target April Fools Day with it, and the next is probably more than 10 years away.

00:00:21.483 --> 00:00:24.347
So I had to squeeze something out of it.

00:00:24.347 --> 00:00:30.077
This week we're back to good old fire science, and in this episode we will be discussing.

00:00:30.077 --> 00:00:33.627
Fire resistance with my good colleague from the office.

00:00:33.627 --> 00:00:34.045
Piotr Turkowski.

00:00:34.045 --> 00:00:42.127
Fire resistance is something that if you are a fire you will work with it, period.

00:00:42.127 --> 00:00:43.746
There is no escape.

00:00:43.746 --> 00:00:47.133
There is no chance you will not be exposed to it.

00:00:47.133 --> 00:00:49.773
Uh, at some point of doing your design.

00:00:49.773 --> 00:00:55.097
Probably doing it literally all the time because work.

00:00:55.097 --> 00:01:04.697
This is something that is just, uh, being used to assess the structural fire engineering, or this is something as a proxy of structural fire engineering.

00:01:04.697 --> 00:01:07.308
Perhaps that's the better way to, to put it.

00:01:07.308 --> 00:01:08.171
And, um.

00:01:08.171 --> 00:01:15.596
For fire resistance, there are multiple components that you have to take into account to understand what it fully means.

00:01:15.596 --> 00:01:19.197
One would be the element and how the element is designed.

00:01:19.197 --> 00:01:25.706
What materials are being used, what are the properties of the material, different elements, different uh, kinds of.

00:01:25.706 --> 00:01:30.453
Specimens will go through a slightly different variations of the fire resistance test.

00:01:30.453 --> 00:01:31.805
We're not talking about that today.

00:01:31.805 --> 00:01:34.287
The second aspect is thermal exposure.

00:01:34.287 --> 00:01:36.628
What type of curve you are using.

00:01:36.628 --> 00:01:39.837
We're also not talking about that today that much.

00:01:39.837 --> 00:01:41.474
The third one would be the furnace.

00:01:41.474 --> 00:01:44.055
What kind of furnace are you using?

00:01:44.055 --> 00:01:49.518
And and there are actually nuanced differences between furnaces in the world.

00:01:49.518 --> 00:02:00.768
However, a lot of effort was put into mitigating those, so, the far resistance on different furnaces in different is somewhat comparable.

00:02:00.768 --> 00:02:03.283
And we're also talking about that today.

00:02:03.283 --> 00:02:19.393
The thing that we're talking about today are the criteria the assessment, the criteria of the fire resistance So what actually is being assessed when a specimen is given a rating when your specimen gets REI 60?

00:02:19.393 --> 00:02:22.883
What does that exactly mean?

00:02:22.883 --> 00:02:27.771
And you could imagine, you could say, uh, yeah, R is load is integrity.

00:02:27.771 --> 00:02:28.973
I is installation.

00:02:28.973 --> 00:02:29.842
That's it.

00:02:29.842 --> 00:02:35.673
But as everything in the world of fire science or fire when you go deep.

00:02:35.673 --> 00:02:43.736
It gets complicated and messy and you find a hundred years stuff that probably should not be there today.

00:02:43.736 --> 00:03:00.358
And yeah, it's, it, it, it's fun and, uh, such as the world fire resistance, uh, criteria, which we are delving into So yeah, please join me in OT in this Fire Fundamentals Let's spin the intro and jump into the episode.

00:03:00.358 --> 00:03:28.323
The Fire Science Show podcast is brought to you in with OFR Consultants.

00:03:28.323 --> 00:03:38.174
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00:03:38.174 --> 00:03:47.353
we've been on this journey together for three years so far, and here it begins the fourth year of collaboration between the Science Show and the OFR.

00:03:47.353 --> 00:04:04.929
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00:04:04.929 --> 00:04:11.739
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00:04:11.739 --> 00:04:35.357
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00:04:35.357 --> 00:04:39.826
Check their website@orconsultants.com And now to the episode.

00:04:40.737 --> 00:04:40.978
Hello everybody.

00:04:40.978 --> 00:04:44.968
I am joined today by my very good colleague, Piotr

00:04:45.730 --> 00:04:45.730
Hi.

00:04:45.730 --> 00:04:46.870
Hello, everyone.

00:04:47.317 --> 00:04:48.403
good to have you back in the show.

00:04:48.403 --> 00:04:54.072
The man Born in the furnace and furnaces is what we will about today.

00:04:54.072 --> 00:04:54.612
Are you ready?

00:04:55.170 --> 00:04:55.170
Ready?

00:04:55.966 --> 00:05:02.663
so, pi uh, fire resistance, as a paradigm, of the, of the fire safety.

00:05:02.663 --> 00:05:08.050
I, I, have a strong feeling that it's something that we with the furnaces in the lab.

00:05:08.050 --> 00:05:09.889
We perhaps have, a little different.

00:05:09.889 --> 00:05:16.149
View on what it is and how it works than the rest of the fire protection engineering, community.

00:05:16.149 --> 00:05:21.512
And the further you go from the lab, the more differently understand it.

00:05:21.512 --> 00:05:29.223
Let's start with what's your opinion on the topic, and then will go into how to understand it as the court says.

00:05:29.887 --> 00:05:34.610
so after 15 years and after the last interview, came

00:05:37.531 --> 00:05:37.531
Okay.

00:05:37.997 --> 00:05:38.117
the topic.

00:05:38.117 --> 00:05:53.278
many as, uh, we are developing our course on fire I digged through it, and found out there's an actual, definition given in ISO standard, the 13, 943 standard.

00:05:54.139 --> 00:05:54.139
Yeah.

00:05:55.194 --> 00:06:11.942
Uh, I really like the definition because even though very simple and at, at the first glance, it get, it some terms that you might find, assessment method or methods being excluded from, but they are not.

00:06:11.942 --> 00:06:19.365
The definition is in a simple term, it's just an of an item subjected to assessment.

00:06:19.365 --> 00:06:27.766
It's not necessarily a test specimen in a It's just the item that you are assessing to extend or to give protection from it.

00:06:27.766 --> 00:06:30.170
For certain period of time.

00:06:30.170 --> 00:06:31.341
And that's it.

00:06:31.341 --> 00:06:42.951
That that's, and, and probably we all understand it way, just that over the past 100 years, we've built some tools and some criteria around it.

00:06:42.951 --> 00:06:51.889
Uh, sometimes we only needed to one try on this and they are now stuck with us for over 50 years or

00:06:52.713 --> 00:06:52.713
Hmm.

00:06:53.156 --> 00:06:55.737
but it's more or less the same as we all understand

00:06:59.040 --> 00:07:05.449
Just the ability to withstand Well, that's actually helpful though when you go deeper into, uh, assessments.

00:07:05.449 --> 00:07:16.459
I know we, we sometimes have, different opinions of what uh, fire resistance, especially as, as you venture into complicated materials like compostible materials.

00:07:16.459 --> 00:07:18.439
But that's a subject for another talk today.

00:07:18.439 --> 00:07:22.999
Let's, let's discuss of, of on fire resistance, on, on, on it is.

00:07:22.999 --> 00:07:27.581
So, uh, perhaps a good place to start would be the criteria fire resistance.

00:07:27.581 --> 00:07:39.281
So the, so the magical letters that appear in front of you know, significant specimen that RE eyes, uh, et Maybe let's try to clarify those.

00:07:40.875 --> 00:07:40.875
Yeah.

00:07:40.875 --> 00:07:55.533
So a very helpful note to that definition says that, have some criteria, as you said, uh, it, it also, uh, the note also says that it's all being used in a fire test.

00:07:56.346 --> 00:07:56.346
Hmm.

00:07:57.333 --> 00:07:57.723
fire test.

00:07:57.723 --> 00:08:08.798
And there we have, the three most important criteria, which is the integrity e and the thermal I, we also have uh, more letters nowadays.

00:08:08.798 --> 00:08:17.750
We have the radiation performance with the W, we the mechanical impact with letter M, C, small s.

00:08:17.750 --> 00:08:30.887
And even more to that, we have some, prefixes, or some other inserts, saying about the exposure Maybe this is the, this is the external fire condition.

00:08:30.887 --> 00:08:33.076
Maybe this is the semi-natural fire.

00:08:33.076 --> 00:08:50.720
it's a constant temperature attack on a, on the then with the classification of more complex, uh, linear joint seals, we get a whole bunch of set of letters describing the orientation of the joint.

00:08:50.720 --> 00:08:59.053
It's weight, its possible, uh, movement, and for types of elements we'll find sets of such letters.

00:08:59.053 --> 00:09:04.327
So starting with the load bearing capacity, r the fundamental one.

00:09:04.327 --> 00:09:25.471
this is just the ability of the test specimen in a that would be a slap or a beam or a column extent that is imposed on that element during fire, either in test or in a real fire, to extent that, uh, that load and to resist the collapse.

00:09:26.701 --> 00:09:26.701
Hmm.

00:09:26.971 --> 00:09:28.110
very, very core definition.

00:09:28.110 --> 00:09:42.384
We have some criteria for it on how to assess it for some elements, uh, well, a total co collapse of the element, may not necessarily be the, the point that want to declare the loss of, uh, load bearing capacity.

00:09:42.384 --> 00:09:45.086
For, for some, it is like a raised floor.

00:09:45.086 --> 00:09:49.418
The only criteria is that you have to observe that, element collapsed.

00:09:49.994 --> 00:09:51.464
so collapse is, collapse is obvious.

00:09:52.163 --> 00:09:53.033
Yes, collapses collapse.

00:09:53.033 --> 00:09:54.144
That, that is obvious.

00:09:54.144 --> 00:09:59.793
but for other elements, this is mainly being with the, the deformation of the element.

00:10:00.557 --> 00:10:00.557
Okay.

00:10:01.144 --> 00:10:05.195
for horizontal elements, that will be the the rate of the deflection.

00:10:05.195 --> 00:10:14.398
for vertical elements, that will be the So a column cannot contract more than 100 of its, height.

00:10:14.398 --> 00:10:20.129
and funny thing, these criteria almost 100 years old.

00:10:20.129 --> 00:10:31.067
I mean, that they've evolved a little over time, very core, experiments and, and calculations on how to develop these values.

00:10:31.067 --> 00:10:34.427
They are, they're coming from 1918, I believe.

00:10:34.427 --> 00:10:35.003
so.

00:10:35.003 --> 00:10:46.187
It is quite a long time ago when somebody, was thinking on how to assess it, and they did it for steel and concrete, uh, later developed in 1950s.

00:10:46.187 --> 00:10:52.230
And that deformation criteria doesn't care that is being assessed.

00:10:52.230 --> 00:11:03.897
it's universal throughout all types of elements, of the material it's made from, whether it's steel, timber, it's, uh, glazing or whatever.

00:11:03.897 --> 00:11:05.547
It doesn't, doesn't, doesn't matter.

00:11:05.547 --> 00:11:12.759
We all know that all of these material materials will behave differently, that all of them can withstand level of deflection.

00:11:12.759 --> 00:11:14.368
It doesn't matter.

00:11:14.368 --> 00:11:16.918
The only thing that matters is the deformation.

00:11:16.918 --> 00:11:21.440
And the deformation is being calculated only based on two factors, one.

00:11:21.440 --> 00:11:30.075
Is the size of the element being the, the length, the span length, OO of a beam or a floor or, or the height of a column or a wall.

00:11:30.075 --> 00:11:31.047
That's it.

00:11:31.047 --> 00:11:53.407
and the other one being the distance from the extreme fiber of the cold design compression zone of that to the extreme fiber of the called design tension So very often in, uh, simple terms, that is the height of the element for a steel beam that will be the height of it for a timber element.

00:11:53.407 --> 00:12:01.269
That would be also the height for a concrete element, not necessarily the concrete intention is not exactly the best material.

00:12:01.269 --> 00:12:21.316
So a designer, that is designing a concrete beam will not actually take into account, the tension of it'll use the concrete strength in the compression So, uh, very often for a simple span, load bearing, that is the area above the, the, the upper part of beam.

00:12:21.316 --> 00:12:41.855
And in the lower part, he will only, or she will only use the reinforcement to calculate the for a concrete beam, that wouldn't be the entire That would be something that is called the D but half a diameter of the reinforcement, or, know, it, uh, very, very detailed.

00:12:45.235 --> 00:12:48.802
I was wondering if we need a Fire Fundamentals episode on, of fire resistance.

00:12:48.802 --> 00:12:53.032
I, I wondered if we will talk about REI for like an hour.

00:12:53.032 --> 00:12:54.322
Is it even possible?

00:12:54.322 --> 00:13:07.880
And now I see we absolutely need a fire fundamental on those criteria because even the simplest things, uh, get, uh, a little bit obscured and, and messy if you improve them for a hundred years.

00:13:09.125 --> 00:13:11.749
And the value of the deflection, it changed over

00:13:12.413 --> 00:13:12.413
Yeah.

00:13:13.067 --> 00:13:22.339
it was being proposed to be, I will call the, the that we use today an X because it, it doesn't really what it is, but let's imagine that it's an x.

00:13:22.339 --> 00:13:28.490
It's, it's a quite large deflection a reinforced slab of 12 centimeters in thickness.

00:13:28.490 --> 00:13:31.533
a span of around 4.5 meters.

00:13:31.533 --> 00:13:38.254
The deflection is approximately something like 40 to centimeters, not millimeters, 50 centimeters.

00:13:39.368 --> 00:13:40.748
On, on a four and a half meter beam.

00:13:41.344 --> 00:13:41.344
Exactly.

00:13:42.216 --> 00:13:42.576
Oh, okay.

00:13:43.144 --> 00:13:43.474
it's a lot.

00:13:43.474 --> 00:13:44.315
it's a lot.

00:13:44.315 --> 00:13:45.725
So let, let's call that value x.

00:13:46.389 --> 00:13:46.389
Yeah.

00:13:46.894 --> 00:13:52.677
value has been changed, something like six years uh, when it was increased by 50%.

00:13:52.677 --> 00:14:02.159
If you ask anybody about the foundations on why it was increased by 50%, I believe no one will be able to tell you why is it?

00:14:02.159 --> 00:14:11.639
So, I remember at San a meeting, there was even a from ISO that wanted to adjust its standard to, to standard and asked why was it this way?

00:14:11.639 --> 00:14:20.278
I think that the answer was basically like, uh, well, it's a con, it's a conclusion of our discussion that we needed to increase the value of 50%.

00:14:20.278 --> 00:14:27.142
So if we have the X that we have now, six years ago it was a bit less, 33.

00:14:28.250 --> 00:14:28.250
Yeah.

00:14:28.250 --> 00:14:33.403
then in 1959 it was half that value.

00:14:35.696 --> 00:14:35.936
one, six.

00:14:36.292 --> 00:14:44.144
see that, uh, in terms of our tolerance of that on when do we declare the the, the collapse of the

00:14:45.144 --> 00:14:45.144
Hmm.

00:14:45.436 --> 00:14:48.225
we are moving towards higher and higher values.

00:14:48.225 --> 00:14:51.740
it's a good thing, I can tell you, I can only tell you that.

00:14:51.740 --> 00:14:57.274
now, nowadays, many elements, collapse into the furnace before they reach such gigantic deflection.

00:14:57.274 --> 00:14:59.345
that is our load bearing capacity.

00:14:59.345 --> 00:15:09.274
Currently, the deflection only the temperature which are very often associated with the fire'cause we say the critical temperature of steel is 500 C degrees.

00:15:09.274 --> 00:15:09.634
Yes.

00:15:09.634 --> 00:15:12.562
One could say sub sentence this doesn't really matter.

00:15:12.562 --> 00:15:16.672
In a test, we can record even higher temperatures and we don't care.

00:15:16.672 --> 00:15:20.129
It's an information, it's a foot for fault.

00:15:20.129 --> 00:15:20.940
Let's say.

00:15:20.940 --> 00:15:27.373
Maybe we can do some extra assessment later on, but doesn't really matter what temperature we'll record an element.

00:15:27.373 --> 00:15:29.591
It only matters what deflection we record.

00:15:30.139 --> 00:15:35.427
But, for some specific tests like tunnels, we do measure right at the rebar and or not really.

00:15:36.071 --> 00:15:36.250
We do.

00:15:36.250 --> 00:15:41.101
And that is the tricky part because the tunnel test

00:15:43.792 --> 00:15:43.792
Okay.

00:15:43.792 --> 00:15:44.086
Okay.

00:15:44.527 --> 00:15:44.527
Okay.

00:15:44.942 --> 00:15:45.753
the elements of it.

00:15:45.753 --> 00:15:46.831
We can record the temperature.

00:15:46.831 --> 00:15:51.033
We have, we use similar equipment, but it's more spalling test.

00:15:51.033 --> 00:15:55.955
'cause we care about whether the sping occurs or insulation test.

00:15:55.955 --> 00:16:00.076
It's not necessarily an entire where we have

00:16:01.942 --> 00:16:01.942
hmm.

00:16:02.418 --> 00:16:05.538
as it is in practice and we declare it's When it collapsed.

00:16:05.538 --> 00:16:08.090
We have more severe criteria there.

00:16:10.346 --> 00:16:10.916
sistance test.

00:16:11.250 --> 00:16:11.639
Cool, cool, cool.

00:16:11.639 --> 00:16:12.451
and, uh, okay.

00:16:12.451 --> 00:16:13.831
It's load bearing capacity.

00:16:13.831 --> 00:16:21.349
so the load part of that, what it bears, how, how does the look in, in the test and, and, and how it is defined.

00:16:22.245 --> 00:16:29.288
That is a very good question and that is actually quite a debate that one could have when start to, to have a test.

00:16:29.288 --> 00:16:32.585
The load, uh, very often is a vertical load.

00:16:32.585 --> 00:16:41.945
So on a wall will have, will have only compression of, for the wall and for horizontal elements, we will likely get only bending or sheer forces.

00:16:42.864 --> 00:16:42.864
Hmm.

00:16:43.144 --> 00:16:53.024
no normal forces, no, no compression for horizontal Although new test methods like the one for tunnels, they do foresee that that could happen.

00:16:53.024 --> 00:16:59.274
Or maybe there is a new test method for members' when we would have tension, in a horizontal element.

00:16:59.274 --> 00:17:08.228
But this is, let's say something new and the, the value of the load, that is something that is quite a because.

00:17:08.228 --> 00:17:15.104
There are at least three approaches that I could say valid, but they're very different in the outcome.

00:17:15.104 --> 00:17:21.345
One could say that a designer designing a building, use so-called design values.

00:17:21.345 --> 00:17:26.894
So he will take into account that the material is exactly perfect.

00:17:26.894 --> 00:17:34.515
So he will take a nominal value of the steel strength, for example, and not the actual yield strength of it.

00:17:34.515 --> 00:17:39.384
And he will not know exactly what loads will be in building.

00:17:39.384 --> 00:17:44.903
So he will take some value and multiply it by a factor of maybe one, 1.5.

00:17:46.001 --> 00:17:46.001
hmm.

00:17:46.252 --> 00:17:52.886
will increase that load he will, in the end, he will the design load bearing capacity of that element.

00:17:52.886 --> 00:18:00.511
So using the lower value of the material properties the design loads in the building, that will be higher values.

00:18:01.113 --> 00:18:01.535
Double conservatism.

00:18:01.535 --> 00:18:02.250
Okay.

00:18:02.746 --> 00:18:02.746
Yes.

00:18:02.746 --> 00:18:03.404
Yeah.

00:18:03.404 --> 00:18:05.891
And in the end, this is all Euro code zero.

00:18:05.891 --> 00:18:07.721
It's a very nice standard.

00:18:07.721 --> 00:18:18.012
It has the, the entire background, explained there, And, uh, that method, is actually the best one we right now in a fire test.

00:18:18.012 --> 00:18:24.104
However, when we do the test, we kind of know exactly what the load is.

00:18:24.104 --> 00:18:27.252
'cause we imply exactly the value that we want.

00:18:27.252 --> 00:18:31.354
it's not that suddenly our hydraulic jack will put

00:18:32.481 --> 00:18:33.096
So, so, so sorry.

00:18:33.096 --> 00:18:35.376
How do you, how do you apply that load?

00:18:35.798 --> 00:18:38.103
We do that with, mostly hydraulic jacks.

00:18:38.103 --> 00:18:46.653
so, uh, it's a hydraulic jack acting on a steel something else that will, put that load, transfer that

00:18:47.567 --> 00:18:47.567
Hmm.

00:18:47.823 --> 00:18:47.823
specimen.

00:18:47.823 --> 00:18:50.209
That, that is one way and second option.

00:18:50.209 --> 00:19:02.029
Also very common one, especially for roofs when the, the load is not so high, we used, weights, uh, could be concrete blocks, that could be cast iron blocks or

00:19:02.740 --> 00:19:03.430
So like a dead load?

00:19:04.241 --> 00:19:04.241
exactly.

00:19:05.192 --> 00:19:05.192
Yeah.

00:19:05.192 --> 00:19:05.432
Okay.

00:19:05.432 --> 00:19:05.642
Cool.

00:19:06.281 --> 00:19:10.813
and this allows us to spread the load more evenly o the entire surface.

00:19:10.813 --> 00:19:14.201
Something that is, uh, sometimes required by the

00:19:15.602 --> 00:19:15.602
Okay.

00:19:16.903 --> 00:19:18.761
applied and not just a point load.

00:19:19.471 --> 00:19:19.471
hmm.

00:19:19.471 --> 00:19:19.862
Okay.

00:19:19.862 --> 00:19:24.362
You are, you were talking about the, the what's happening with load further in the test.

00:19:24.362 --> 00:19:24.602
Yeah.

00:19:25.303 --> 00:19:30.553
So in a test, we know exactly how much we'll, uh, and we also can measure material properties.

00:19:30.553 --> 00:19:33.853
We know exactly what yield strength that steel has.

00:19:33.853 --> 00:19:42.166
so an argument is made even in the standard itself maybe you shouldn't use the design values because they will not be conservative.

00:19:42.166 --> 00:19:48.765
They do, it'll not be the most onerous scenario for it, that maybe you should use the actual material in a test.

00:19:48.765 --> 00:20:08.607
And to go even further, maybe you should build two specimen and simply with one, do a load bearing capacity test without heating and to to see exactly how it can carry, and then apply a portion of the load you expect to occur in fire.

00:20:08.607 --> 00:20:11.222
During a fire resistance test.

00:20:11.222 --> 00:20:13.577
so there are many approaches to it.

00:20:13.577 --> 00:20:14.593
They are not standardized.

00:20:14.593 --> 00:20:27.743
And unfortunately in many test reports or in many papers, you will not find exactly how the load was calculated, makes, uh, replicability of some very difficult.

00:20:27.743 --> 00:20:30.833
'cause the load influences everything.

00:20:30.833 --> 00:20:50.048
It, it'll dramatically change the outcome of since tests, especially for masonry, for steel for concrete, maybe not so much, but still, but many are very sensible to, to load, especially at a very load ratio because.

00:20:50.048 --> 00:21:05.833
may start appearing the initial deformation will be causing the element to behave differently, in a virus test to the one if the load was lower or if, or, or, or if the element was unloaded completely.

00:21:06.834 --> 00:21:10.010
This is very interesting because of course, uh, you will buy fire protection.

00:21:10.010 --> 00:21:12.800
It'll have a value of R 60 or 120.

00:21:12.800 --> 00:21:25.265
You, you'll, uh, have a, a wall of specific rating, but to have understanding of how that load was applied or what critical were there in the test.

00:21:25.265 --> 00:21:28.835
Can the, can the fire safety engineer even get that somehow?

00:21:28.835 --> 00:21:35.261
Or, or it's like irrelevant if you're doing like fire material on top of steel, let's say.

00:21:35.865 --> 00:21:48.223
For, for fire protection systems, for steel we are in a very lucky positions because these it's an en N 13 381 standards.

00:21:48.223 --> 00:21:55.528
The way they were developed, they give an exact on how to calculate load and how much to, to apply it.

00:21:55.528 --> 00:22:12.166
And for some standards like steel protection, it said that if you apply the load, when you apply the during fire test and that load is insufficient to the collapse of a, in a predicted of temperatures of element.

00:22:13.076 --> 00:22:13.076
Hmm.

00:22:13.382 --> 00:22:27.632
Then you shall increase that load and make it because we want, we want to see during that test, high deflection of that steel element, we want to see how fire protection system will respond to that high

00:22:28.691 --> 00:22:28.691
Hmm.

00:22:30.780 --> 00:22:30.780
Okay.

00:22:31.501 --> 00:22:39.717
in this test, but for others tests like test for roofs or for walls without any fire protection systems, but just the elements themselves.

00:22:39.717 --> 00:22:49.000
This is the gray area on how exactly the load being, and what value of it is being applied.

00:22:49.519 --> 00:23:04.050
How, how translatable is that load to the real world Because it's not just, you know, the, the, the force is one but also how the item is fixed, how it forms a part of the at large.

00:23:04.050 --> 00:23:09.192
This is also critical for the load paths, load-bearing to, appear.

00:23:09.192 --> 00:23:12.413
So how translatable is this to real world situation?

00:23:13.073 --> 00:23:24.421
For fire protection systems, the way, uh, the load is calculated, it's supposed to cover the most honorable scenarios where the load utilization level is even at a hundred percent.

00:23:24.960 --> 00:23:24.960
Okay.

00:23:25.471 --> 00:23:30.260
it is very often 60 to 70% of the load, that can happen, in normal situations.

00:23:30.260 --> 00:23:31.760
So in fire, this is.

00:23:37.968 --> 00:23:37.968
Hmm.

00:23:38.423 --> 00:23:41.939
a, a glimpse into the future on maybe if we'll talk Eurocodes as well.

00:23:41.939 --> 00:23:47.230
uh, for other elements, it is not required to entire load, especially for roofs.

00:23:47.230 --> 00:24:04.481
This doesn't really make, uh, makes much sense 'cause you can imagine easily a scenario where, we have a like last year, so there's actually snow, Maybe the normal operation, the, the roof we have above our uh, must withstand that entire snow load.

00:24:04.481 --> 00:24:08.353
But during fire, it'll not necessarily be that much.

00:24:08.353 --> 00:24:18.489
So again, using Euro codes, we can see that the snow in a fire situation is usually being, decreased to only 20% of its value.

00:24:18.489 --> 00:24:28.627
So in fire, roofs are almost never loaded to their load bearing capacity because it doesn't make It's more or more like 20 to 40%.

00:24:28.627 --> 00:24:32.583
it's enough because when you then calculate all the

00:24:34.767 --> 00:24:34.767
Hmm.

00:24:35.018 --> 00:24:43.144
the dead weight of it, and you also, Take into account that you use design values, that load will get reduced.

00:24:43.144 --> 00:24:51.786
So in a fire scenario, it'll be simply less and only that no need to overkill it with even more load.

00:24:52.357 --> 00:24:52.357
Fantastic.

00:24:52.357 --> 00:25:00.173
And anything more to add for the basics of load bearing next?

00:25:00.173 --> 00:25:00.624
E.

00:25:01.233 --> 00:25:04.535
at this point I, I, I think we should move to the E.

00:25:04.929 --> 00:25:04.929
Yep.

00:25:04.929 --> 00:25:05.739
Let's keep integrity.

00:25:05.739 --> 00:25:08.381
What's, tell me, tell me all about integrity.

00:25:08.381 --> 00:25:11.192
what does it represent and, and how do you measure it?

00:25:11.748 --> 00:25:18.203
The integrity E is one of the three parameters, uh, we use to describe.

00:25:18.203 --> 00:25:34.217
Elements that has a separating function in case of fire separating, meaning you can use it to enclose a fire in a compartment and not have it spread all over the this is one of, uh, of the tree.

00:25:34.217 --> 00:25:38.567
'cause we have the integrity E, the I and the

00:25:40.016 --> 00:25:40.016
Hmm.

00:25:41.655 --> 00:25:41.865
is the.

00:25:41.865 --> 00:25:58.769
Most important one of them, I'd say, this is the one kept, when, when we say that the element has integrity, E we're saying that is blocking the spread of fire direct, flaming through that element.

00:25:59.790 --> 00:25:59.790
Hmm.

00:26:00.067 --> 00:26:11.230
are blocking spread of fire by flames coming out of the element or maybe some cracks that can appear in that or some joints of, specified size.

00:26:11.230 --> 00:26:19.108
We have that also quantified or, simply by hot gases could pass through even smaller cracks.

00:26:19.108 --> 00:26:26.278
But that could ignite something that is adjacent to wall or floor on the unexposed, uh, side.

00:26:26.278 --> 00:26:29.351
So this is the integrity that,.

00:26:29.351 --> 00:26:33.713
that criteria Is possible to be, to be assessed only a test.

00:26:33.713 --> 00:26:43.723
There is no, virtual cotton pad or, flame in a numerical analysis that you could do to, to it.

00:26:43.723 --> 00:26:49.365
So, the very reliable way to assess it is almost through a test.

00:26:50.087 --> 00:26:50.449
how it's done.

00:26:51.019 --> 00:26:54.412
so we have three, uh, three ways to, to assess it.

00:26:54.412 --> 00:26:56.662
Although one of them is a bit tricky.

00:26:56.662 --> 00:27:00.105
Um, maybe we shouldn't go that deep, but I think

00:27:03.641 --> 00:27:03.819
I'm curious.

00:27:03.819 --> 00:27:07.948
I'm very, very curious, especially when it comes to, you pitfalls so far.

00:27:07.948 --> 00:27:08.508
Safety, engineering.

00:27:08.508 --> 00:27:09.626
So yeah, go there.

00:27:10.194 --> 00:27:10.194
Yeah.

00:27:10.194 --> 00:27:15.019
So the, the first non non-controversial one is a su sustained, flaming.

00:27:15.826 --> 00:27:15.826
Okay.

00:27:16.219 --> 00:27:22.397
if you can observe with your own eyes, and it's very that you do it with your own eyes because a camera very

00:27:25.688 --> 00:27:25.688
Hmm.

00:27:25.847 --> 00:27:26.147
just disappears.

00:27:26.147 --> 00:27:29.420
It has to be continuous for a period of 10

00:27:30.384 --> 00:27:30.384
Okay.

00:27:30.769 --> 00:27:31.220
it, if it breaks.

00:27:31.220 --> 00:27:34.308
During that period, you start the countdown again.

00:27:34.308 --> 00:27:45.266
It has to be 10 seconds of continuous flaming on the side, and at the end of the measurement of this 10 you declare, okay, integrity is gone.

00:27:46.118 --> 00:27:46.118
Okay.

00:27:46.704 --> 00:27:48.718
on the unexposed side, integrity is gone.

00:27:48.718 --> 00:27:50.692
The second one are gaps.

00:27:50.692 --> 00:27:52.343
And there are two types of gaps.

00:27:52.343 --> 00:28:05.798
you have a single opening in the element, simple gap, crack, whatever that goes through the entire Through its entire thickness and it's more than 25

00:28:07.836 --> 00:28:07.836
Hmm.

00:28:08.377 --> 00:28:09.097
you've just lost integrity.

00:28:09.798 --> 00:28:09.798
Mm-hmm.

00:28:10.239 --> 00:28:21.546
The other type of gaps are the ones that are only six millimeters in size, but they are length of So in a test, you basically have two rods.

00:28:21.546 --> 00:28:24.651
One is 25 millimeter in a diameter and the six.

00:28:24.651 --> 00:28:36.134
If you can put them through the entire element into the furnace chamber without excessive force, without anything on its way, then the integrity is gone.

00:28:36.452 --> 00:28:36.692
No hammer.

00:28:37.528 --> 00:28:37.740
No hammer.

00:28:37.740 --> 00:28:38.308
No hammer.

00:28:38.308 --> 00:28:49.423
And uh, for for many elements, you will find that have some, uh, fixings every, let's say a hundred And if you, uh, if you start putting that rod and it

00:28:51.601 --> 00:28:51.601
Okay.

00:28:52.392 --> 00:28:54.342
damage the element by, by pushing.

00:28:54.342 --> 00:29:04.116
So for, for some elements, uh, they're not being For example, for linear joint seals, we don't use, gauges because they would simply destroy the very

00:29:04.971 --> 00:29:04.971
Mm.

00:29:06.020 --> 00:29:06.020
Mm-hmm.

00:29:07.063 --> 00:29:22.419
The third one, that's the tricky one because in a and everywhere you'll see that the cotton pad the, to the annex post surface, is something that is, uh, criterion of integrity.

00:29:22.419 --> 00:29:24.519
So the cotton pad is.

00:29:24.519 --> 00:29:40.663
As far as I remember, three to four grams of steel wire cage uh, that has some extensions so that not exactly touching the element, the, the, the surface, but it's something like 10 millimeters away it.

00:29:40.663 --> 00:29:44.595
that if you apply to any crack to, to any part of the surface.

00:29:44.595 --> 00:29:49.545
But yeah, in reality, it's, it's being applied to or to hot areas.

00:29:49.545 --> 00:29:52.509
It cannot ignite, when applied for 30 seconds.

00:29:52.509 --> 00:30:01.795
Yes, but it is clearly transfer of fire from one to another through that flaming or through hot gases.

00:30:01.795 --> 00:30:11.298
But at the same time, if the insulation performance not being assessed, so the eye criterion is not being assessed, use cotton pads.

00:30:11.298 --> 00:30:21.243
Because Cotton Pad, even though it's an integrity it's something that in reality, in a fire instance, test causes you to lose the insulation.

00:30:21.243 --> 00:30:32.980
there is a proposition, because the, the, the the EN 1363 dash one standard, is now, uh, starting get, a work item in sense.

00:30:32.980 --> 00:30:34.506
So it'll go through a revision.

00:30:34.506 --> 00:30:41.343
there's a proposition for many years to that cotton path from integrity to insulation.

00:30:41.343 --> 00:30:43.152
I will develop it.

00:30:43.152 --> 00:30:45.132
Maybe I, I will get back to it.

00:30:45.132 --> 00:30:50.471
Uh, when talking about the insulation, I, and you start to see why it makes sense.

00:30:50.471 --> 00:30:52.122
So I'll do it right now.

00:30:52.871 --> 00:30:52.871
Yeah.

00:30:53.260 --> 00:30:57.550
ins, the insulation eye is another separating function criterion.

00:30:57.550 --> 00:31:03.356
but this one, uh, is not about the passage of fire one side to another.

00:31:03.356 --> 00:31:08.269
With flaming it's with only the temperature of the Yeah.

00:31:08.269 --> 00:31:20.990
So the temperature of the surface cannot get hot enough so that something that is adjacent to that surface ignite just because of the contact with the element of, with, with high temperature.

00:31:21.548 --> 00:31:24.940
Oh, of the unexposed surface, of course, outside of the Okay.

00:31:25.759 --> 00:31:29.391
So that could be, I dunno, a poster, glued to, to the surface.

00:31:32.035 --> 00:31:32.035
Mm-hmm.

00:31:32.661 --> 00:31:33.351
some, something like that.

00:31:33.351 --> 00:31:35.761
The, the, the values are very low.

00:31:35.761 --> 00:31:36.810
are two values.

00:31:36.810 --> 00:31:42.510
There's the average temperature rise of 140 kelvins the initial temperature.

00:31:42.510 --> 00:31:44.642
So let's say the initial one was 20.

00:31:44.642 --> 00:31:55.442
So the temp, the average temperature of this surface cannot exceed 160 degrees Celsius, and the temperature rise is 180 VINs.

00:31:55.442 --> 00:32:00.902
So with the same initial temperature, it's not more 200, uh, degrees Celsius.

00:32:00.902 --> 00:32:05.288
the base for these values are also very old.

00:32:05.288 --> 00:32:09.366
They're, they were criticized over many years.

00:32:09.366 --> 00:32:19.605
Very famously, they were criticized by, by the outer of the two best papers, uh, that I recommend for the of fire resistance testing.

00:32:19.605 --> 00:32:20.430
professor.

00:32:20.430 --> 00:32:28.355
So Professor Barca, is, uh, criticizing these values as being very, very low, very conservative.

00:32:28.355 --> 00:32:37.117
in a paper from something like 10 years ago in a safety journal, he proposed that value to be at least 300 CES or even more.

00:32:37.117 --> 00:32:41.644
And, to, to be honest, I do think that these values are quite low.

00:32:41.644 --> 00:32:53.471
and sometimes they're so low we make an exemption for door sets, these values, for the frame are not but they are 360.

00:32:53.471 --> 00:33:01.067
They're increased because for steel doors, are impossible to, to maintain, uh, below that threshold.

00:33:01.067 --> 00:33:10.284
so now when you, when you think about it, the, the, cotton pot, why would it ignite on the unexposed there is no flame.

00:33:10.284 --> 00:33:15.624
'cause if there's flame, obviously it would ignite and you would observe sustained, flaming.

00:33:15.624 --> 00:33:17.874
So this is the criteria E.

00:33:17.874 --> 00:33:29.752
So you, you see that the, the, the mechanism, of igniting the cotton pad is very much the, the but at the same time.

00:33:29.752 --> 00:33:45.432
If you lose the installation performance, if you care about the temperature anymore because it's you are, you are no longer classifying your elements for for E only, then the cotton pad is excessive because

00:33:48.509 --> 00:33:48.509
Hmm.

00:33:49.211 --> 00:33:57.843
with flame, it would only, it could only also the heat is passing through the element and integrity is not about hot gases so much.

00:33:57.843 --> 00:34:05.476
It's about the direct, direct flaming, direct fire, over the, the entire, fire separating element.

00:34:06.275 --> 00:34:10.295
Yeah, I, I, I have some follow up questions about those, criteria, both e and I.

00:34:10.295 --> 00:34:24.487
So for integrity, perhaps it's just a polish thing because in Polish, the, the poor world we word, which you're very of, the word that we use for integrity would translate more like, tightness in English.

00:34:24.487 --> 00:34:31.657
And people hearing about the integrity, they would expect there is literally no smoke passing through.

00:34:31.657 --> 00:34:39.847
Like, I often see that when we host some tours in the lab, people are surprised, oh my God, there's so smart, so much coming through the element.

00:34:39.847 --> 00:34:41.018
Did it fail?

00:34:41.018 --> 00:34:41.708
Well, no.

00:34:41.708 --> 00:34:43.237
Well, it doesn't ignite the pad.

00:34:43.237 --> 00:34:44.018
So it doesn't fail.

00:34:44.018 --> 00:34:52.538
So, so if you could comment on how much can pass through wall, like literally until it, until it, uh, ignites the pad, you're good.

00:34:52.538 --> 00:34:52.748
Right?

00:34:53.429 --> 00:34:53.429
Exactly.

00:34:53.429 --> 00:35:01.110
We have a really nice video footage of one of the that, uh, Pavo and Jaggers were testing.

00:35:01.110 --> 00:35:03.340
can't see the test specimen.

00:35:03.340 --> 00:35:09.731
The, the, the entire unexposed surface is full of dense yellow smoke.

00:35:09.731 --> 00:35:12.820
You can't see nothing, absolutely nothing.

00:35:12.820 --> 00:35:21.161
It's smoking, uh, that after five minutes, the, the of our facility is full of that smoke.

00:35:21.161 --> 00:35:22.331
Doesn't matter.

00:35:23.920 --> 00:35:24.550
whatever it wants.

00:35:25.155 --> 00:35:25.530
still met it.

00:35:27.023 --> 00:35:27.023
Yes.

00:35:27.023 --> 00:35:30.293
If you apply, if there's no sustain flaming, if there

00:35:31.992 --> 00:35:32.202
or gaps.

00:35:32.722 --> 00:35:33.893
that 60 millimeters yes.

00:35:33.893 --> 00:35:36.893
Or the cotton pad doesn't ignite, doesn't matter.

00:35:36.893 --> 00:35:41.259
can be, uh, whatever amount of smoke is.

00:35:41.827 --> 00:36:00.556
Yeah, I, I, I always like find this something very, very And, uh, for installation, it's, I also found it quite funny that, you are not very free to measure it where, where you it, it's like specific locations at which you are supposed measure.

00:36:00.556 --> 00:36:09.617
And when you say like, average on the surface, it, it's average of the points that are being pointed and measured.

00:36:09.617 --> 00:36:09.978
Right.

00:36:09.978 --> 00:36:24.099
I, I always try to, to convince our colleagues, uh, or you take that much convincing to, to put a thermal camera in front of, of the furnace, but that's not how this, this field of, of, of fire safety engineering works.

00:36:24.099 --> 00:36:25.358
We're very traditional.

00:36:26.197 --> 00:36:26.197
Yes.

00:36:26.197 --> 00:36:34.530
Uh, the standard, to be honest, the standard doesn't anything about the, terminal camera or whatever that you could use during the test.

00:36:34.530 --> 00:36:38.505
for some reason, everybody thinks you, you, you can't do it.

00:36:38.505 --> 00:36:39.525
You have to measure the temperature.

00:36:39.525 --> 00:36:46.574
So for the average rise, you have five prescribed Sometimes it's six, sometimes it's more.

00:36:46.574 --> 00:36:56.481
But in, in a very general way, there are five points from any discontinuity, away from any, places be, let's say, difficult.

00:36:57.626 --> 00:36:57.626
Hmm.

00:36:58.072 --> 00:37:03.981
And then for the maximum temperature rise, you have a set of, uh, set of points that are being considered.

00:37:03.981 --> 00:37:12.771
Weak points, like the very top of the element or maybe the fixed edge, maybe near the joint, maybe near the joints.

00:37:12.771 --> 00:37:22.226
you, you, you could apply the thermocouple wherever you want, wherever you feel that, the temperature could be worse, but you cannot put them everywhere.

00:37:23.056 --> 00:37:23.056
Yeah.

00:37:23.396 --> 00:37:30.056
cannot cover the entire specimen with thermocouples say, well now, now I'm really measuring every week's spot.

00:37:30.056 --> 00:37:45.507
But in case during the test, a weak spot, uh, develops, like, I dunno, you start to see that maybe there was a severe concrete spawning in one place, or maybe was, uh, maybe only one board of fire protection fell.

00:37:45.507 --> 00:37:53.217
And there is, uh, you, you, you can see the, the start to getting brown like charring on the unexposed area.

00:37:53.217 --> 00:37:58.954
You can always take a roving thermocouple and apply it to that location and measure the temperature.

00:37:58.954 --> 00:38:02.014
Uh, whatever, whatever you want during the test.

00:38:02.014 --> 00:38:09.882
But there is a, a small yet quite important In Europe, we use thermocouples with pads.

00:38:09.882 --> 00:38:25.760
So we have a thermocouple attached to a copper that copper disc is covered with, uh, a tiny bit of material, so that it doesn't radiate so much of, uh, o of the heat away.

00:38:25.760 --> 00:38:31.221
In, in us they use also cotton pot, but they, cotton

00:38:34.518 --> 00:38:34.518
American.

00:38:34.940 --> 00:38:36.440
pots Amer Yeah, they are, they are American.

00:38:36.440 --> 00:38:40.599
They are big and they insulate these thermocouples more.

00:38:40.599 --> 00:38:42.856
And the roving thermocouple doesn't have any.

00:38:43.675 --> 00:38:43.675
Okay.

00:38:44.532 --> 00:39:09.356
if you measure, say 200 cent degrees with a roving You can be sure that a thermocouple that would have attached to that location prior to the test and was that point, uh, all along it would have, uh, got the earlier, maybe three minutes, maybe five minutes, maybe even 10 minutes for some elements.

00:39:09.356 --> 00:39:14.771
the temperature on the unexposed surface is rising ever so slowly.

00:39:14.771 --> 00:39:19.871
That without these paths that could, that they would

00:39:22.179 --> 00:39:22.179
Hmm.

00:39:22.601 --> 00:39:27.190
obviously the unexposed area is always radiating part of that heat.

00:39:27.190 --> 00:39:30.672
So if it's hitting too slow, it'll not get to it.

00:39:30.672 --> 00:39:41.862
And I remember a few tests where, going from like 150 cent degrees to around 200 cent degrees

00:39:45.942 --> 00:39:45.942
Hmm.

00:39:46.152 --> 00:39:56.387
even a technician walking in front of the furnace and causing some air, air movement make a sudden drop of 0.50 cent degrees on the thermocouple.

00:39:56.387 --> 00:40:00.931
So, there are some quirks about that measurement as

00:40:01.820 --> 00:40:06.818
Well, in the end, like, uh, would that make the, the more dangerous?

00:40:06.818 --> 00:40:20.623
I, if it, uh, takes hour to, to heat up by a few degrees, kind of a game always, uh, like, uh, you know, to get a, to get the rank ranking, to get a, a certificate, to put a product the market for fair.

00:40:20.623 --> 00:40:23.172
This is the point of, of doing, uh, of doing this.

00:40:23.172 --> 00:40:38.010
But while there are things that I believe highly translated to real safety, sometimes those things, uh, are, you know, uh, just kind of a game, but an, anyway, um, we, we still have a few more to go, more exotic ones.

00:40:38.010 --> 00:40:49.739
You've mentioned radiation, you've mentioned Let's start mechanical impact maybe, or no, let's start You said that's three, uh, criterion related to far spread insulation, and radiation.

00:40:50.371 --> 00:40:51.001
Let's cover radiation.

00:40:51.001 --> 00:40:51.570
Why?

00:40:51.570 --> 00:40:55.590
It's WW why there's, like RR was taken.

00:40:55.590 --> 00:40:57.420
I get it, but yeah.

00:40:58.443 --> 00:41:01.353
Uh, yeah, that's a, that's a good question.

00:41:01.353 --> 00:41:06.603
So, uh, you know, uh, the standards are being uh, on a European level.

00:41:06.603 --> 00:41:09.483
So this one is from a, uh, German word.

00:41:09.483 --> 00:41:12.813
let me butcher the pronunciation for you.

00:41:12.813 --> 00:41:13.952
Uh, it's, uh.

00:41:13.952 --> 00:41:16.068
Very strong.

00:41:16.068 --> 00:41:21.632
so, so, that would be that, you didn't ask why the

00:41:24.465 --> 00:41:24.465
Okay.

00:41:24.465 --> 00:41:26.239
Yeah, that's, that's a fair question.

00:41:26.764 --> 00:41:30.719
this one is from French, so, uh, let me butcher it as well for you.

00:41:30.719 --> 00:41:32.860
That would be the Aton.

00:41:35.039 --> 00:41:35.784
Well, Mr.

00:41:35.784 --> 00:41:40.885
Worldwide Good, uh, too many common letters for those Okay.

00:41:40.885 --> 00:41:43.045
Let's, let's talk, what was it?

00:41:43.045 --> 00:41:43.643
Warm telling?

00:41:43.643 --> 00:41:45.235
Uh, let's talk ling.

00:41:45.235 --> 00:41:48.565
What, why, what does the, the Rhodesian criteria represent and

00:41:52.704 --> 00:41:53.518
In, in, in, in a way.

00:41:53.518 --> 00:42:02.998
I, I would call it the weakest one, but it's the most severe integrity criteria, let's say, because this doesn't allow for, for, for much.

00:42:02.998 --> 00:42:09.605
So the radiation performance, is a third way of the, fire separating function.

00:42:09.605 --> 00:42:20.494
this time we don't care about the passage of flames, we don't care about the temperature of the surface, we about radiation of the surface.

00:42:20.494 --> 00:42:24.844
So it's not about the elements that are adjacent to wall.

00:42:24.844 --> 00:42:36.617
Thi this is about the elements that are on the other wherever they are, if they can receive that radiation and uh, and ignite themself from it, this is what we assessing.

00:42:36.617 --> 00:42:38.063
uh.

00:42:38.063 --> 00:42:39.793
There is no temperature measurement.

00:42:39.793 --> 00:42:42.643
Obviously there is no, uh, observation.

00:42:42.643 --> 00:42:51.492
There is the radiation measurement happening, and criterion is 15 kilowatts per square meter.

00:42:52.036 --> 00:42:53.387
If you think it was per, okay.

00:42:53.387 --> 00:42:56.956
It's obviously applied only to transparent elements.

00:42:57.735 --> 00:42:57.914
Not necessarily.

00:42:58.764 --> 00:42:58.764
Okay.

00:42:59.085 --> 00:43:24.851
could, uh, you, you can imagine, um, a kind of, blanket or other type of material that is also being used to, uh, to divide space into smaller compartments, maybe a rolled up Uh, it, it doesn't have to be transparent, but when it's very thin, it can still get very hot and thus it can radiate enough heat.

00:43:24.851 --> 00:43:29.052
It is being mostly used for glazed elements, but not,

00:43:30.621 --> 00:43:30.621
Okay.

00:43:30.621 --> 00:43:37.427
but, but do, do you ever have an element that would be just by the W or it's always in combination with something?

00:43:38.503 --> 00:43:43.304
So the combination of classes are usually the, the e be on its own.

00:43:43.304 --> 00:43:49.193
So we can have E 30, say, I always has to go, has to

00:43:51.867 --> 00:43:51.867
Okay.

00:43:52.373 --> 00:43:52.554
as well.

00:43:52.554 --> 00:43:55.014
So it's EWEI or E.

00:43:55.708 --> 00:43:57.898
And all of them with, with the load bearing, so REI.

00:43:59.213 --> 00:43:59.213
Exactly.

00:43:59.213 --> 00:44:01.902
the, the insulation performance.

00:44:01.902 --> 00:44:05.427
The thermal insulation, I, uh, when, when it's

00:44:10.289 --> 00:44:10.588
Makes sense.

00:44:11.244 --> 00:44:18.143
if the temperature is below the, the threshold, you get the the W And if you lose the integrity, if you e.

00:44:18.143 --> 00:44:22.163
are losing all, everything else, you are losing the, insulation.

00:44:22.163 --> 00:44:23.813
I you are losing the radiation.

00:44:23.813 --> 00:44:29.902
W if you're losing load bearing capacity, then you are truly losing everything.

00:44:29.902 --> 00:44:37.583
'cause when there is collapse of the element, we, we, we, we can't assess it anymore for, for the fire function.

00:44:38.541 --> 00:44:47.186
It makes sense that with I, you keep the w because it'll take you more than 500 degrees to, to, to, uh, to radiate 15 per square meter.

00:44:47.186 --> 00:44:52.496
And that's at like perfect back body, so probably close to 600 for real items.

00:44:52.496 --> 00:44:53.936
So, so, so, makes sense.

00:44:53.936 --> 00:44:57.297
What about, uh, class M mechanical impact?

00:44:58.492 --> 00:44:59.047
mechanical impact.

00:44:59.047 --> 00:45:06.713
It's probably the DM and mechanical is probably not because it's, um, another German invention.

00:45:06.713 --> 00:45:11.213
So probably there's a, there's another word for it.

00:45:11.213 --> 00:45:12.262
Um, mechanical impact.

00:45:12.262 --> 00:45:12.862
Uh.

00:45:12.862 --> 00:45:15.713
Is being used mostly in Germany.

00:45:15.713 --> 00:45:38.525
And, uh, This is a verification of, uh, of firewalls uh, for unforeseen impact, not only from the from the vertical load, the, the compression, the, the axial force that we applied to that wall, but maybe, a piece of the roof, uh, falls off and hits that and we need to see the response.

00:45:38.525 --> 00:45:47.195
And the me mechanical impact is not exactly the response of the element to that, to that impact.

00:45:47.195 --> 00:45:54.947
it is verifying that the other criteria are still So, during a test, say after 120 minutes.

00:45:54.947 --> 00:46:17.074
You decide to not have only REI one 20 for your but you want to have even more, you want to have REI 20 dash m so you can say that my wall can, can mechanical impact from whatever is falling from the or is applying some horizontal load to my wall during fire.

00:46:17.074 --> 00:46:25.045
The way you will do it is that just after reaching this 120 minutes threshold, apply.

00:46:25.045 --> 00:46:35.284
That mechanical impact via, a bag filled with, lead that weighs approximately, uh, 200 kilograms.

00:46:35.284 --> 00:46:39.393
uh, it's on an arm of 1.5 meters.

00:46:39.393 --> 00:46:48.385
So you have that uh, sack of lead balls hitting the center of the wall three times.

00:46:49.260 --> 00:46:50.750
Like a, like a wrecking ball.

00:46:51.266 --> 00:46:51.896
like a wrecking ball.

00:46:51.896 --> 00:46:52.226
Exactly.

00:46:52.226 --> 00:46:57.835
And the first two impacts, are happening when the wall is still being bloated.

00:47:01.199 --> 00:47:01.199
Mm-hmm.

00:47:01.643 --> 00:47:06.835
'cause you can easily imagine situation where the is holding the element in place.

00:47:06.835 --> 00:47:10.855
And maybe when you remove that load, then it's a truly wrecking ball.

00:47:10.855 --> 00:47:17.184
So there are two hits while the element is still And the third hit when it's unloaded.

00:47:18.543 --> 00:47:18.543
Mm.

00:47:19.400 --> 00:47:20.849
And, the element still stands.

00:47:20.849 --> 00:47:32.581
then have minutes to further assess the load bearing So did the contraction of that element increase the, the criterion?

00:47:32.581 --> 00:47:34.715
You assess again, the integrity.

00:47:34.715 --> 00:47:43.967
Did the, did this wrecking ball cause any more, cracks or openings or whatever that I can, uh, say that lost integrity?

00:47:43.967 --> 00:48:02.280
Or did they cause this element to deform in such way that thermal installation is not being kept if during two minutes, after all these three hits, criteria are, are maintained, you can add to your dash m.

00:48:04.110 --> 00:48:04.110
impact.

00:48:04.458 --> 00:48:20.449
w when I saw that for the first time, you had this really nice video of, of the ball going like straight through a wall it really gives you, you know, I'm, I'm pretty sure that when promoting this episode, you will happily link the video once again on LinkedIn for anyone interested.

00:48:20.449 --> 00:48:37.005
But, uh, it, it like gives you another dimension that you While something can be still standing and, and, and be the function, because it just exists, it sometimes doesn't take much to, to have this damaged element to lose it.

00:48:37.005 --> 00:48:46.139
And, and this is often a, a difference between a building, building, not surviving, firefighters being safe, being unsafe.

00:48:46.139 --> 00:48:46.989
Yeah.

00:48:47.835 --> 00:48:48.181
Even more.

00:48:48.181 --> 00:48:58.811
I, I, I'd like to notice that, in our Polish national regulations, somebody, uh, thought that, know, 20 dash m.

00:48:58.811 --> 00:49:02.974
is one class, but the mechanical impact test is not

00:49:04.072 --> 00:49:04.072
Okay.

00:49:04.773 --> 00:49:07.773
So maybe not many manufacturers have that ification.

00:49:07.773 --> 00:49:23.768
So in one of the regulations, for waste manage sites, uh, there's a requirement that firewall must be of REI one 20 dash m class, or, and this is being an equivalent, 240.

00:49:23.768 --> 00:49:31.027
So they switch the mechanical impact for double the and it doesn't work that way.

00:49:31.027 --> 00:49:39.969
For reinforced concrete, maybe that would be reinforced concrete can withstand that mechanical impact easily, but for many walls.

00:49:39.969 --> 00:49:56.666
Reaching four hours of, fire resistance for REI 240 that difficult as to withstand three times a wrecking And exactly the video that you are referring to is a that has just passed four hours.

00:49:56.666 --> 00:50:03.882
So it's REI 240, but it collapses under the first So it's not the same.

00:50:03.882 --> 00:50:15.434
It's, there are two very different classifications, but we have our, our, uh, law bringers lawmakers, uh, not yet very familiar with the topic.

00:50:16.262 --> 00:50:31.623
I mean, there's not very many people familiar with the topic, if I'm honest with you, because, uh, we are, uh, having fun this as insiders who are doing this for living, you know, uh, unfortunately, what happens in Vegas stays in Vegas.

00:50:31.623 --> 00:50:39.971
So what happens in fire lab stays in far lab, and that, unfortunate reality of, of, of, of the world of fire safety, engineering and, episodes like this are, are.

00:50:39.971 --> 00:50:42.791
My way to perhaps change this a little bit.

00:50:42.791 --> 00:50:44.746
Um, you brought me to the time aspect.

00:50:45.137 --> 00:50:51.947
If we still have some time, I would love to talk about I know there are many other criteria which would be more specific.

00:50:51.947 --> 00:50:56.896
Uh, I think we covered the main, uh, important ones and I want to talk about time.

00:50:56.896 --> 00:51:02.306
So Piot, a 30 minute wall plus 30 minute wall is a 60 minute wall, right?

00:51:03.998 --> 00:51:08.460
Yeah, obviously has to be, I mean, it could.

00:51:09.179 --> 00:51:09.179
It.

00:51:12.775 --> 00:51:13.284
But it could not.

00:51:13.284 --> 00:51:27.922
you know, the, the more I work with this, the more I to say I don't know, because after so many years dozens of tests, I can say I, I, I've seen some stuff that I would never think of, that that would happen.

00:51:27.922 --> 00:51:35.003
And I've lost my arms and legs and my head and my already so many times when I was betting that, that could never happen.

00:51:35.003 --> 00:51:35.992
And it happened anyway.

00:51:35.992 --> 00:51:37.043
yeah.

00:51:37.043 --> 00:51:38.784
Maybe for, for reinforced concrete.

00:51:38.784 --> 00:51:39.204
Absolutely.

00:51:39.204 --> 00:51:44.152
Because going from 30 minutes to 60 minutes is, it's an increase of 20 millimeters of concrete.

00:51:44.152 --> 00:51:46.164
So obviously you'll, you'll, you'll get that.

00:51:46.768 --> 00:51:46.768
Yeah.

00:51:47.364 --> 00:51:54.652
But, uh, for a lightweight partition, if you put them one next to another, uh, no, I wouldn't be so because.

00:51:54.652 --> 00:52:02.958
the, the second one is getting way bigger, uh, heat after the first one collapses than the first initial 30 minutes.

00:52:02.958 --> 00:52:03.228
Yes.

00:52:03.228 --> 00:52:11.347
It's, it's like with charing of timber, you can have protection on timber, and then you calculate the grade, uh, very differently.

00:52:11.347 --> 00:52:17.197
So without any fire protection, you get this magic let's say oh 0.7 millimeters per minute.

00:52:17.197 --> 00:52:21.068
And it's a steady value, constant value of charring, timber.

00:52:21.068 --> 00:52:24.083
if you get fire protection, is not like that.

00:52:24.083 --> 00:52:39.920
After, let's say 30 minutes when the fire protection off, uh, the timber starts to char at oh 0.7 No, it's, the charring is very rapid and it's back to the value it want to always be, when there was no fire protection.

00:52:39.920 --> 00:52:41.510
So it doesn't work this way.

00:52:41.510 --> 00:52:45.853
And we, we also say it for concrete, for, uh, for fire protection of concrete until.

00:52:45.853 --> 00:52:48.820
The, the fire protection stays in place.

00:52:48.820 --> 00:52:58.179
We can, can see its influence on the fire performance, but one, once it's gone, the temperature in concrete is also rising very rapidly.

00:52:58.179 --> 00:53:01.081
the, the countdown doesn't begin at zero.

00:53:01.081 --> 00:53:16.478
The temperature that, uh, the, the second leaf of wall or that element is, starts to be exposed to, 0 cent degrees rising to 608, 800 after 30 minutes, are starting at 834 cent degrees.

00:53:16.478 --> 00:53:16.867
Yes.

00:53:16.867 --> 00:53:19.208
So it's already a huge impact on that element.

00:53:19.907 --> 00:53:19.907
Mm.

00:53:20.137 --> 00:53:20.347
It can.

00:53:20.347 --> 00:53:48.893
Even just the, the temperature gradient, the sudden of the very cold element to not 20, not a hundred, not 600 centimeters, but to a heat from furnace, of very uniform radiation inside, to 900 This can cause even, col collapse than it would if was heated from the beginning.

00:53:48.893 --> 00:53:52.338
Another two examples, uh, quick ones is, is the

00:53:53.273 --> 00:53:53.273
Yeah.

00:53:53.958 --> 00:54:02.960
sping is very often way more severe when you expose the concrete to greater gradient of temperature between the heated zone and unheated zone.

00:54:02.960 --> 00:54:12.797
if you have fire protection and it's gone after some concrete, uh, and, and the concrete was, uh, cold, very likely explode.

00:54:12.797 --> 00:54:15.496
We, we, we've seen it many times.

00:54:15.496 --> 00:54:17.717
It, it literally explodes.

00:54:17.717 --> 00:54:26.047
uh, and second example, o of that is why we assess, some elements with, more severe fire curves.

00:54:26.047 --> 00:54:34.963
We, we didn't say it, but the standard fire uh, standard fire curve, but we have hydrocarbon fire, have RWS and they are very steep.

00:54:34.963 --> 00:54:36.702
They're in three minutes.

00:54:36.702 --> 00:54:41.322
We are, we are supposed to reach 1,100 C degrees or 1200 C degrees.

00:54:41.322 --> 00:54:49.414
Just this small change that the element is suddenly exposed to these extreme temperatures, causes to it behave differently.

00:54:49.414 --> 00:54:53.940
So a 30 minute wall plus 30 minute wall is unknown.

00:54:54.978 --> 00:54:54.978
Yeah.

00:54:55.500 --> 00:54:55.650
is unknown.

00:54:56.358 --> 00:54:59.650
and, and also like the hours are not even to each other.

00:54:59.650 --> 00:55:07.931
So, uh, the, the, like the fourth hour of fire resistance test is a very different heat load than the first hour of fire test.

00:55:07.931 --> 00:55:11.831
So it's not like it's just 60 minutes or 30 minutes more.

00:55:11.831 --> 00:55:16.922
Fire resistance, It, it's like a different product overall with a different resistance.

00:55:18.114 --> 00:55:18.114
Absolutely.

00:55:18.425 --> 00:55:19.291
That, that's how I understand.

00:55:19.291 --> 00:55:25.411
And, and how, when, when you measure that in, in the furnace, do you like, sit with a stopwatch and like 60 minutes pass win?

00:55:25.411 --> 00:55:27.239
Or, when do you assess it?

00:55:27.239 --> 00:55:28.793
It has passed a 60 minutes.

00:55:28.793 --> 00:55:29.094
Is it?

00:55:29.094 --> 00:55:29.902
Exactly 60 minutes.

00:55:30.532 --> 00:55:31.217
NN yeah.

00:55:31.217 --> 00:55:37.456
The, there's, the short answer is if you get 60 on the clock, it's 60 minutes.

00:55:37.456 --> 00:55:46.050
I mean, I don't want to get anyone nervous about, stating that the, uh, REI rating is the same as 60 of fire or whatever.

00:55:46.050 --> 00:55:48.090
We're talking about the furnace minutes.

00:55:48.090 --> 00:55:50.820
If you get 60 minutes, you get REI 60.

00:55:50.820 --> 00:56:01.974
The uncertainty of the entire test method is unknown, and we get a beautiful note in our testing says exactly that.

00:56:01.974 --> 00:56:03.353
The uncertainty is unknown.

00:56:03.353 --> 00:56:05.693
We cannot assess it in any way.

00:56:05.693 --> 00:56:11.956
Maybe we could quantify a bit the temperature the time measurement, and so on, but the this is unknown.

00:56:11.956 --> 00:56:15.347
So there is no, safety rule below.

00:56:15.347 --> 00:56:24.927
Safety above, or whatever there Uh, there is only one rule, and that rule is what you read exactly on the is exactly the rating you're getting.

00:56:24.927 --> 00:56:26.217
And the same goes for temperatures.

00:56:26.217 --> 00:56:31.407
We know that the thermocouples, are for the uh, surface temperature.

00:56:31.407 --> 00:56:33.266
They are plus minus four Kelvins.

00:56:33.266 --> 00:56:35.817
This is the requirement from the standard.

00:56:35.817 --> 00:56:45.440
know that our thermocouples are more like plus one and a half Kelvin, but it doesn't matter if you 180 Kelvins.

00:56:45.440 --> 00:56:54.539
It's gone if the measurement is above that okay, you, you, you could go through the documents of that exact thermocouple that you used and see.

00:56:54.539 --> 00:57:01.599
Oh, but that this thermocouple, makes the temperature, uh, recording, one Kelvin higher than it should be.

00:57:01.599 --> 00:57:01.898
Yeah.

00:57:01.898 --> 00:57:03.219
So maybe I have one more Kelvin.

00:57:03.219 --> 00:57:05.588
Maybe I have this 30 seconds more or something.

00:57:05.588 --> 00:57:07.088
No, doesn't matter.

00:57:07.088 --> 00:57:12.494
if it's within limit the thermo couple, the reading That's it.

00:57:12.494 --> 00:57:13.125
That's your criteria.

00:57:13.125 --> 00:57:14.085
And the clock.

00:57:14.085 --> 00:57:15.014
60 minutes.

00:57:15.014 --> 00:57:15.494
Oh.

00:57:15.494 --> 00:57:15.675
Oh.

00:57:15.675 --> 00:57:17.175
You got REI 60.

00:57:21.362 --> 00:57:22.592
to say in French for our French.

00:57:23.451 --> 00:57:24.050
you get a Class D?

00:57:24.050 --> 00:57:40.233
Well, I mean, it's, it's, it's, uh, I ask this obviously uh, I've seen some conversations and, uh, it's that, that, that they failed like seconds to, to, to the And, uh, yeah, that, that, that's probably very, very for the clients.

00:57:40.233 --> 00:57:41.043
But, uh.

00:57:41.670 --> 00:57:43.829
Uh, it is what it is.

00:57:43.829 --> 00:57:46.710
A, a as, as you said earlier, sometimes it's a game.

00:57:46.710 --> 00:57:48.809
Some manufacturers treat it as a game.

00:57:48.809 --> 00:57:59.804
They, when they, when they are designing a product seconds more and not more, because that more Cost money.

00:57:59.804 --> 00:58:04.844
So they want to get the product for exactly the rating they want to sell it for and not more.

00:58:05.538 --> 00:58:06.018
yeah, yeah.

00:58:06.018 --> 00:58:11.251
Another, another aspect, uh, of the industry that, many would not be aware.

00:58:11.251 --> 00:58:11.670
Pi.

00:58:11.670 --> 00:58:22.891
I had like a long list of things on fire resistance to but I think we've done a good job covering the criteria of resistance and I hope our listeners enjoyed that.

00:58:22.891 --> 00:58:30.568
And I would welcome you once again, uh, to the podcast to the beautiful world of, uh, fire resistance, uh, once again.

00:58:30.568 --> 00:58:32.757
And thank you very much for today.

00:58:33.268 --> 00:58:34.018
For your anytime.

00:58:34.018 --> 00:58:35.759
Thank you, for having me.

00:58:35.759 --> 00:58:36.869
Thank you very much.

00:58:37.387 --> 00:58:37.838
And that's it.

00:58:37.838 --> 00:58:44.027
I promised you it's complex and not easy, and I hope, satisfied with this discussion.

00:58:44.027 --> 00:58:55.097
I am very much satisfied with this discussion because Piot uh, very good at what he's doing and is been doing far tests for as long as I remember in my professional career.

00:58:55.097 --> 00:59:01.518
Uh, it's a man who's seen hundreds of those, so I take his uh, very strongly.

00:59:01.518 --> 00:59:26.083
In this episode, we try to show you some of the insiders because I often feel very, hmm, how to say it, disturbed by the fact that, uh, fire resistance is being treated like an comparison between the elements, especially when, when talk like putting something like a timber structure or you want change.

00:59:26.083 --> 00:59:40.143
Completely the type of the structure, let's say from concrete to annex exposed steel or to protected steel, or maybe even as simple as comparison between two fire protection Should I use spray paint?

00:59:40.143 --> 00:59:41.884
Should I use mortars?

00:59:41.884 --> 00:59:43.954
Should I use fire protection bolts?

00:59:43.954 --> 00:59:48.858
They all have the same rating, and while to extend, it's interchangeable.

00:59:48.858 --> 00:59:54.407
I need to recognize that this fire resistance is.

00:59:54.407 --> 01:00:08.862
Performance of a individual element or individual and, and while the minutes are the same, while the furnace is the same, the different criteria make comparison between groups of those elements.

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Impossible.

01:00:09.802 --> 01:00:17.842
Like if you compare a column for resistance to, for of a ceiling slab, it's obvious it's two different values.

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'cause one is a column, it's a vertical, and slab is and completely different load, completely different criteria for deflection, contraction, et cetera.

01:00:27.356 --> 01:00:43.059
I think at that case it's, it's quite easy to to understand the comparison is not there, not the direct one, but, uh, you talk about different, like say fire protections of beams or, or some, something that would be perhaps similar in the use, uh.

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You need to understand the nuances that, that go into it.

01:00:46.641 --> 01:00:51.141
And then I hope we, we brought some nuances of that, uh, to today.

01:00:51.141 --> 01:00:55.311
And, uh, I hope we will be able to talk with Otra a little bit more.

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Uh, we'll do a calculation methods episode as well.

01:00:58.610 --> 01:01:06.726
So, so that would come complete the, this, uh, perhaps take on fire resistance and, uh, I really hope it's gonna be.

01:01:06.726 --> 01:01:08.460
A good one as well.

01:01:08.460 --> 01:01:21.630
And uh, for now, I would like to thank you for being here me on this beautiful day, and I hope to see you here again Wednesday for another episode of the Fire Science Show.

01:01:21.630 --> 01:01:22.891
Thanks for being here with me.

01:01:22.891 --> 01:01:23.280
Cheers.

01:01:23.280 --> 01:01:23.880
Bye.