070 - Fire resistance is whatever you want it to be with Piotr Turkowski

Wojciech: 0:00

Hello everybody. Welcome to the Fire Science Show. Today we're touching the subject of fire resistance or resistance to fire. Well, we're actually gonna set that up and later in the episode it's something that, uh, we do here at the itb at our fire testing laboratory. And I'm, many times I have told you that we find professionals, especially ones that work with fire resistance as a concept of work with fire resistance tests. We understand that thing a little bit different than most of fire professionals because we. Know some insider stuff that dictates how materials behave, how they pass the test, what's happening, uh, within the test. So for today, I thought that it may be a great lesson for the fire engineers to learn something about how fire resistance is actually done in the fire laboratory. And for that purpose, I didn't have to look far for the guest. It's, it's my great colleague Dr Piotr Turkowski uh, who I had the privilege to sit across the desk. And I've learned so much about fire resistance from that time. I'm sure, uh, now having him on this on this podcast will, uh, allow us to, to learn a lot about it together even more. So, yeah, Piotr is already here. Hello p. Great to have you here.

Piotr Turkowski: 1:19

vj. Nice to see you. to be

Wojciech: 1:21

Long time to see . Great to have you in the podcast. Finally, Piotr, you are very involved. Like can you give a brief introduction, to yourself to, to the listeners? Uh, I mean, you are representative of ITB and CEN committees for fire resistance testing. You're our man in EGOLF you are doing, lectures on how to perform fire tests properly. But yeah, give us a few words about yourself,

Piotr Turkowski: 1:45

that was actually a very nice introduction. Thank you. Uh, so yeah, I work at ITB for over 11 years right now, actually almost 12. So I did, hundreds of tests witnessed double the amount. I, do participate in CEN committees, CEN TC 127 particular, and CEN 250, so the one for new, for euro codes and the one for, fire reasons testing. I also do, give some of my opinions, uh, on EGOLF Forum. I also participate in those meetings in fire sector group. Basically, for the past few years I've been sent to any fire group. There that has, something to do with, with our work in the laboratory I, did my PhD on, carbon fire polymers, fire protection of, of, of such for reinforced concrete structures. yeah, say that is, brief summary of my person

Wojciech: 2:41

thank you very much. You can also name emotions in, in musical tracks, which I find amazing. And you also somehow know Euro codes by heart, which I find disturbing . So let's jump into the, the subject fire resistance. So if a person on the street, if you pick a random person on the street and, tell them if, I have a wall which have one hour fire resistance, what does that mean? I, my guess would be they will tell you, Oh, it will resist fire for one hour. But, that's not very precise answer to the question because the question, Well, as I know working, uh, with you at itb, fire resistance is a very precise thing. So, first of all, let, let's try to define it like what exactly is a fire resistance rating and fire resistance on its own?

Piotr Turkowski: 3:30

I think this is a very good topic to start with because it's a very misunderstood concept of what fire resistance is. if we go into testing, we would, define fire resistance in classes and a fire resistance class is something else. Then fire resistance instance itself, because fire class includes a test method, which you have used to demine this parameter, and it also includes the criteria you have applied to it. So for example, if I say a fire instance class uh, of a concrete beam R 60, and that I will say that I have achieved that class during a test. It'll mean something completely different if I say the same thing, but I would define the fire resistance class for example, a Euro code does, or other person could actually define his own parameters because the Euro code will use the temperatures inside the steel reinforcement. It would actually use, uh, bending momentum criteria or she resistance and stuff like that, whether in fire resistance testing. The only criterion for load bearing capacities is actually deflection of the element. can be of any temperature whatsoever up to certain point of deflection, which is quite insane. we, we would say that it has the fire resistance, for example, this exact parameter has changed two years ago. Before we had, one value of that deflection, I will not bother you with the equation, right now have multiplied the deflection by one and a half. So we actually allow 50% more deflection. And I think this approach is actually still better than the one that was, also because what people proposed at CEN was that. Only the failure, the breaking of the test specimen, its collapse, can be considered as loss of load bearing capacity, fire resistance. And we actually can observe the quite thing. For example, roofs tends to have a breaking point after something like 10 minutes where they suddenly increase their deflection by 20 centimeters very rapidly, and then they stop. And sometimes it's enough to lose load bearing cap and sometimes it is not, but there is no failure. That roof can withstand another 20 or 30 minutes of fire. So fire resistance is basically what you want it to be. if you define your You present them to the reader, then obviously he will, he will know what you mean. But if you go and say to someone, Yeah, I have a wall of one hour five resistance, that actually means nothing. It, it means absolutely nothing. So, yeah, the thing we do in the laboratory and the thing we do in our, opinions most of the time, because we also act, according to the, uh, legislature, asks us for fire resistance classes. And it asks us for certain parameters in accordance with certain that E 13 5 0 1 part two or Euro codes. So we have to follow them up whether we like it or not. Whether we agree with, with those criteria or not, we just follow them because that's basically the way that has been adopted, that allos. to be compared.

Wojciech: 6:54

It's a little disturbing. Fire resistance can be whatever you want it to be. I mean, it seems like the answer is 42 to that question in that case. Um, anyway, you've mentioned it being multiple things at the same time. On one way it is like, a cooking. for the test, you know, add this amount of, of heat or temperature to the furnace. Measure this parameter. If it goes beyond this, it's failure. If not, it's okay. Measure the time with a specific uncertainties. Measure everything around. And this is, like the outcome of the test is, is truly the fire resistance as tested for. The common man. It could be how long my building will withstand the fire without defining what the fire is for firefighter, it could be, uh, or for the legislator, it could be a very convenient way to parametize fire safety in the building code. Well, you just need one number, like R 60 or REI 120. You're good if you, if your thing does the, this test in this way, you're good. And, and then for the manufacturers, it would, it would be another thing as you said, it's a tool for comparison. It's like a measure in which they can compare the, properties of their products measured in, let's say, all in the same way. Because they did every, every product would have their own stunt. And I think this is also important. We measure fire resistance. building elements, like you measure a wall, you measure a column, you measure a ceiling, but we don't really measure the, the whole systems together. We don't measure the viruses of a building. Right. like how, how tricky it is to convert, for example, a slab from a building into the fire test. I mean, it'll act completely different in, in the furnace than in the building. Right. You're a structural engineer. Enlighten me.

Piotr Turkowski: 8:43

that's exactly the case. And obviously, every lab, so are we, We are limited by our furnaces by the furnace size. There is a way to build a big furnace. We, we do have two such furnaces. One of them, that we called Chime can, can be extended to 12 meters span of elements. But at the same time, if you take a 12 meter span element, like, a concrete beam or maybe pretre floor, you calculated deflection when, then you start to wonder, hmm, is the 3.7 meter depth of our furnace enough to accommodate for the deflection? Because the ter goes insane. The criterias are, are written as for a standard, uh, size of test like three by three meters is four walls and four by three for, for floors. And then maybe they work, but otherwise, We start to see some insane, uh, deflections allowed or insane, uh, rate of deflections where the test specimen could bent toward our furnace to half of its depth and have, I dunno, burners above the actual test And it wouldn't still be as a failure. So, so obviously there is a great limitation, of what we can test and then how it applies to actual building There are two ways to deal with that. We can build bigger furnaces, and so did we. We built a Phoenix furnace, which is seven meters stolen, 10 meters wide, and very, soon, witnessed test that, uh, made our previous understanding of of test specimen irrelevant because suddenly completely different failure modes occurred. example, for, lightweight partitions made of gypsum boards. The whole world three by three meters walls, but the actual need was for much bigger walls, like maybe in a cinema or in theater, or in other spaces where you had to have like eight meter tall wall, maybe even 12 meters. So what, what can you do if you only have a three by three, furnace? You can start to calculate Uh, but what happened when we've tested such wall? Well, the, the unexpected happen because the, the wall didn't fail because of the deflection. It didn't fail because of the tempera. It failed because the actual length of the arc of the wall, once it deflected, made it disconnect from the top It basically unfixed itself from the, from the lintel. So , so, it failed in a way that no one has ever thought of thought before. what the producers do right now, they create that kind of telescope, a special device at the top of the wall to make it, move downwards and upwards, uh, throughout the entire test or maybe throughout the fire in, in your building. Cause we only can say what we saw in, a test, and that was unexpected. The same thing with, hollow core concrete slabs. Well the first thought of everybody was, Well, what's difficult about It's just You calculate bending momentum, you calculate temperature of the reinforcement, and you have everything. And then people started testing those and. didn't fail because of bending they failed because of sheer failure. And then they failed because the anchorage was not enough, in, the Anchorage zone. And it's very funny to observe how that knowledge spreads to standards. Because if you go for a standard for holo the Eem 1168, you read its first from 2000 something, it's bending failure is enough. Then you go have plus A1. Well, bending failure is not enough. You have to consider sheer. Then you have plus A2 know what actually include Anchorage as well. And then there's plus three addition. You know what the sheer and Anchorage is actually way more severe. And if you go with the same slab between these four additions of the standard, go from r e i 180 to r e i 60, something like that for the same product. And throughout the years, people, were doing that. And it's incredible because the standard was issued in something like 2005, and I okay, I don't because I wasn't at ITB at that time, but I know that we have done such tests in 2002 at ITB together with DBI from Denmark. we've done such tests and we've shown this, this problem. And it took, CEN only 10 years to incorporate that into the standard,

Wojciech: 13:19

which for is actually not that slow

Piotr Turkowski: 13:22

Forsen is actually not slow unfortunately. But 10 years later, yesterday I had an opportunity to review a paper submitted to a journal, last three months, something like that. And it was about hollow core and hollow sphere, concrete slabs and all that. Knowledge is not present. People only care about bending. They still forget about shear. They still forget about the anchorage, and they don't include that in their calculations.

Wojciech: 13:51

So you, you, you said that the way, to understand bigger elements, to understand the effects of scale, which at this point we were relying purely on, on calculation methods or our predictions or our expectations on how bigger elements would behave. Now, now we can build , bigger furnaces to convey bigger elements to observe these effects of scale. My issue with that, It's in a way critique of my own laboratory. but it is what it is. My issue with that is that the furnace was never a great representation of a real fire. even, you know, the three by three meter furnace, if we, even if you assumed that it's, fully flash over fire, it, it's not a perfect representation. well, it's not a representation at all. It's, it's just a, a furnace condition. However, as you build bigger furnaces, the further away you go from real fires, like the big furnace we have is stand by seven meter tall. Like the hell. What, what kind of fire does that represent? I mean, it is gigantic. I, I really struggle to imagine a fire that would have uniform conditions because that, that's also a point the furnace is, is meant to provide you in uniform conditions over the sample. I struggle to see a fire that would provide uniform conditions over, over sample. So maybe we're, you know, these telescopes, these, these, uh, solutions that are invented to pass the test. are they going further away for fire from, from near fire? Are they serving the safety or just serving the class? That, that, that's like a, that's something I struggle with

Piotr Turkowski: 15:23

a really good point, which I was trying to get to. But it's a really good point showing that, the first way we, can deal with bigger elements with real buildings is bigger furnaces is actually not the way because they do not represent real fires. These fires would have to be insane to be so long, so over the entire volume, the entire space that is in fire. we do get away from what the actual fire is. the other option is actually not better because the other option is calculations. And that's the way that our so-called EXAPs, the extended application, uh, of test results. are they go with calculations, but the way they do it they cut so much science out of them to basically incorporate only that apply that, that include addition, maybe some multiplication, maybe one more factor or something like that. And sometimes even not, not even that, they are just wishes. if we keep the lightweight partitions, in, in place, you can do 12 meter wall with that up, but. The way you do it? they say, Okay, the way you can have a higher wall, you just have to have an overtime. You know, if your wall was 60 minutes and you get 66 minutes, that's good enough, know, and then you, and you can start building higher walls. This is absolutely not a scientific and I don't want to be mean to anybody who wrote that. I know how hard it is to work such standards And that's basically the reason why New EXAP standards have to have their background to see to, for people to see how people came with such solutions. But what they do is, is that there is no science in that for masonry walls. this, it's almost the same. If you have managed to get your wall for 60 minutes and the deflection of the wall towards the furnace wasn't bigger than half of its thickness, which is almost never the case. then you can raise the wall up to eight meters because of reasons basically.

Wojciech: 17:33

Okay. , it's important to, to say that to, to people who are not involved in writing the standards. in this part of fire engineering, the people involved in, in this committees are usually two types of people. Either there are people representing the laboratories, which, I'm sorry, they haven't, their interests, like there are certain sizes of elements written in the standards for a reason because it's, it's the furnaces that exist. You don't want to write a standard for furnaces that do not exist because then people have an issue. And the other group is, manufac. Producers, uh, in a way love this, you know, that, that represent the, their own particular interests of, putting products on the market. And I essentially, there is nothing wrong with, that as long as we understand it is like that, it's not a group scientists who would start thinking, what is the ultimate measure of safety of a masonry wall? And let's define it, how to build the safest wall in the world. No, it's not that. It's, it's about how can we put the product on the market with the standardized test that everyone on the table agrees to, right.

Piotr Turkowski: 18:39

Yes. That, that, that's exactly the, the group of people, uh, we meet at CEN

Wojciech: 18:44

they're great people. They're smart people, They're nice people. it's in their agenda. They come to the meeting, which is related to where they work, who they work for, and what, how, how they earn their living. It. It's not about the people, it's about the system.

Piotr Turkowski: 18:56

Yeah,

Wojciech: 18:58

I I had to say that. I like these people

Piotr Turkowski: 19:00

I, like people very much. each one of them, it's really nice to meet them, uh, even though it's only on teams, uh, right now, but, I like to see myself a person that, uh, acts on the benefit of a user that I, I don't want to write a standard or in writing a standard that, increases the amount of testing that needs to be done, if it's unnecessary, if if it misrepresent the science we have. And one example of this can be, uh, seen in Euro code versus the fire testing fire protection of concrete elements. Because in Euro code, in the new the up to a very high class of concrete, C 70 immune to sping. But in fire testing, every is, is susceptible to spawning and you have to test a range of concrete classes to actually give that. And I am finding very hard to change that, to reduce the, the amount of testing that needs to be done. But otherwise you can see some insane. actions from the manufacturers, especially glazed partitions. In glazed doors where they do have very complex elements. Glazed door is made of 60 to 80 components and each one of them have some influence over the fire You have a lock, you have the closing

Wojciech: 20:17

Gasket shield. Nope. Everything has an

Piotr Turkowski: 20:20

the gel, the glass, the aluminum class, everything. So, there's a lot of parameters. So obviously they don't, they do not want to make a hundred tests because it's, it, it costs, it's basically a cost. And in the end, who will pay that? It's not them, will be the users, the product will be simply more expensive. So I'm, I'm trying to balance, this, but it's a really hard topic to balance, especially because of the way we perceive certain criteria and the way we measure them. Some of them are very the temperature. temperature is, is quite obvious, but it's also a point of discussion. And, we do, do stick with the 140 and 180 Temperature rise over the unexposed surface most of the time. there are voices, that comes from important people like Babrauskas who says, No, it's, it's too low. You can rise it up to 300, maybe even four, 400 cent degrees. And that would change the whole market because suddenly so many other products could be seen as fire, resistance,

Wojciech: 21:25

Sorry, but, but the challenge. do we even know where these values came from? This 140, 180? Like or are these are the words written in the code forever and no one even dares to, to touch the origin of them. Because it is also very interesting as a concept. It's, it has, the fire resistance as a concept has a buildup of a hundred years for now. So do we, do we know that?

Piotr Turkowski: 21:48

I know just a little, and I don't know if it's big, big Uh, I, yes, maybe just some rumors and I don't know if it's because, such knowledge doesn't exist or maybe I just didn't have time or skill to dig up to it. But, as for the temperature it's supposed to represent the element that could be on the other side that could ignite from the temperature itself. And Babrauskas argues that, that this is, if that's the case, that the temperature needed is not that, it's not way more than that. So why do we stick with such low temperatures?

Wojciech: 22:24

if I had to place a bet, I would bet that someone just a hundred years ago, they just did the test. Okay, that looks okay. Let's stick with that. and , if I had to bet money, my money on that, I, I would put it on on that. And if any one of you listeners know the origins of that, I'm very interested in learning that because, uh, oh boy. as a fire safety community, we have totally lost our ability to understand where the magic numbers came from. And, yeah, that's one of my goals in the podcast, you start talking about,

Piotr Turkowski: 22:54

Yeah, I, I'll go. I just want to give one more story about the

Wojciech: 22:57

Yeah. Yeah.

Piotr Turkowski: 22:59

we, do stick with the let's say Calvins as a temperature rise. Yes. But sometimes not so convenient. Sometimes the market actually can influence the way we perceive fire resistance. So for example, in Great Britain, they have a ton of, uh, wooden door. Yeah. They like them and they can keep this they can maintain the temperature, rise below the value. But if you have steel door with steel frame, there is absolutely no way this is, this is just too much of insulation you are asking. So what we did, Well, if you cannot keep the I1 let's go with I2. That allows you to have a temperature rise of 360 kelvins in certain areas. So, you know, if it's not convenient, can change that. But otherwise, let's keep the criteria as for thec. Well, that's a story of, many aspects on how to gain the fire testing on how to gain the product being good for the test. But you have absolutely no idea how it'll behave in a real fire or maybe you have very limited amount of knowledge. I, I don't want to be and want to speak in such absolute, So why is that? ENT paint works because it swells, because it produces that foam in air or gases inside of it. those gases. Are basically the insulation, but the activation of the products inside intumescent paint doesn't happen just like that. It happens because a certain heat flux acts on it. a standard testing, first of all, the temperature always rises. Second of all, the temperature rises in very particular way. You have a pre described fire curve, and then if that heat acts on paint, some first products will start to swell at 200 cent degrees, then maybe at 250, 300 and so on, up to a point where you have a really nice foam that start to insulate your temperature rise still gets much, much lower. And then you can keep, the temperature below a certain temperature of, let's say 500 cent degrees for maybe 30 or 60 minutes, maybe even 90. But what would happen if that fire wasn't like that? What could happen if your fire very small at the beginning? Maybe it's only 200 cent degrees, but then suddenly you have the flash over and then it goes like standard temperature. Well, people thought of that and they introduce the smoldering curve, and some countries require that. Some, some do not. And you check whether your paint would behave in a same manner. Whether whether it'll still

Wojciech: 25:46

In a, in a much lower temperature, in a much slower curve

Piotr Turkowski: 25:51

in, a much lower curve at the beginning and then when it goes, to the regular curve. But there are two curves they've tested and that's it. would happen if you had the opposite? What would happen if you have, ENT paint on an element that could be subjected to very rapid and very high temperature fire at the beginning, and then it gets lower. So, for example, a hydrocarbon fire, that would be completely different behavior and it, it will, it was observed. I mean, we do it all the time. We can see that the ratio of the paint is not exactly the same for the, for one curve or another. And when I said about gaming, the, the fire testing, well fire testing the first. Five to 10 minutes is basically chaos. It's mayhem. Anything can happen in the furnace. it, almost doesn't matter what your temperature is because your criteria start to kick in around the 10th minute. It almost doesn't matter what the pressure is because also it, the disc, this criteria kicks in, uh, after five minutes. So you have a period of, when, you can do in test something that will influence your test result, but something that will never be seen by anyone who only reads, uh, the classification in the end. So we had, such who knows that who know what to do to game. And they've asked us, for example, to increase the pressure the furnace in the first minutes. Because it doesn't matter, because it will help to activate the product, the so it swells better that that's one way. The other way to game it is that standards are not perfect. They tend to give some, some what your test specimen should be, but then you choose such test specimen. And I'm speaking particularly about paint and sprayed mortars or, board fire protection systems, the one which in accordance to E 13 381, part four and part eight, where you can take such load bearing beam your failure occur at such point that you will get always the best, correction factor. don't want to go into much detail on, on on what that is. I think that if people know these products and know what correction factor is, they will know how much it influence the, the results. So people are gaming that and, we change standards because of this, but know only as little as we have fought ourselves or what the customers told, told us. But they some ACEs up their sleeves,

Wojciech: 28:30

it's everywhere where you as a family because, uh, if you have just as a family of products, it is literally impossible to test them all. So there must be a way to extending the, the individual tests into the performance of whole family. We have the exact same thing in natural smoke ventilators where we assess the discharge coefficient of the ventilator, and the standard basically tells you what types of vents to take for this test based on their, the ratio of their dimensions. And it tells you to take at least four. Sometimes you can take a little more than that and then just find which combination of four between them gives, the most, optimistic, uh, assumption about the performance of the family. And I mean, that's the way how the industry works. I, that's why I wanted to do this podcast as, as well, because, uh, the fire resistance or, or the fire properties, how they are assessed in the laboratory, it is a much, much bigger story than just the index. It's not that you take the same wall, put it in the furnace, in Poland, in France, in uk and expect it to be the exact, same. There are these mini school differences, of course, in our e golf groups, uh, in our CEN commissions. We, we, we, we share this knowledge. We, we try to. Work up the standards. So they're harder to game that are more unbiased. But it, it's a slow process. But you, you've also mentioned that, in scientific papers, you have not observed the, in a particular paper, you have not observed the, growth that you have observed in, in, in the standard. And, and from this talk alone, we already see there's so much knowledge hidden in the laboratory. People. Does this knowledge surface anywhere else than CEN committees? Does your experiences or experiences of our colleagues in other labs actually influence how, how fire safety is delivered in the world? Or is it a secret knowledge, passed from generation of lab workers to the next generation?

Piotr Turkowski: 30:29

Uh, honestly, I'm starting to doubt it even surfaces in CEN anymore because the way the new standards are, changing, euro code for masonry walls. I don't think that, there is enough, proof for the claims that these standards, uh, wants to introduce. Uh, it the same happens for glaze products. And, for example, we are working currently or beginning to work for fire protection for aluminium products, and we've asked everybody to share their test results. I think for the past 12 months we haven't received any. So maybe laboratories keep them to themself. Maybe don't want, they don't want to publish them. But I think, there's another topic here that is influencing very much how we fire testing. And this is the, uncertainties that are inherent to fire testing. And we see them much, especially in round Robins. I, I've heard you like stories. I will give you the story that will makes you not want to do any fire test anymore. So you've mention, you've mentioned EGOLF EGOLF is a great It's a group of fire laboratories. There are very many of them. We tend to be number one there. So we like them. We like share the logo on our test

Wojciech: 31:49

Unfortunately, the EGOLF is not longer Googleable because of introduction of electrical golf from Volkswagen. I say, Oh yeah,

Piotr Turkowski: 31:57

So I, I will share you, I will share with you this,

Wojciech: 32:00

I need to give you the link. You cannot Google it

Piotr Turkowski: 32:02

there's a link. It's egolf.global. There's no way you could think of global as domain, but it exists. So egolf.global, that's, that is your address. So they do round Robins and Round Robins are great when you think about them. And then they are very you start to compare the test results. So they. Many, round robins in for the past few years, and I want to talk about two of them. which I have, personally participated in and the one that happened recently that caused so much trouble and such ripple in fire testing will hopefully change many ways that we do fire testing. So the first one is about steel beam. Imagine steel beam made without any fire protection material whatsoever. All of the steel beams come from one factory. They do have the same properties or basically the paper They do have all the same properties. The steel beam is HEB 300 It's loaded in a very little way. It's only about 20% of it load bearing capacity. And each lab tests two of such beam. You, you couldn't imagine a more test. only still beam. And if we

Wojciech: 33:25

No, No

Piotr Turkowski: 33:26

no protection whatsoever, only steel, fully exposed to fire on three sides.

Wojciech: 33:31

Hmm.

Piotr Turkowski: 33:32

And we were talking about the criteria, the deflection criteria were made for steel. They weren't made for concrete, they weren't made for timber, for any other product. They weren't made for steel. the, the in itself basically applies to the very test are testing so many labs. think there were over 20 participated in this run. Robin, you imagine what the spread of test results was being

Wojciech: 33:58

20%

Piotr Turkowski: 33:59

would be really nice. the actual spread. I will give you our results. don't want, I don't want to do a commercial of itb, but it'll be a commercial of ITB because we have to tested two such being, the difference in our test results was 15 seconds the failure. It was 29 minutes and 29 minutes and 15 seconds. So basically I'd say, yeah, that this is nice.

Wojciech: 34:22

And the B was designed for 30

Piotr Turkowski: 34:24

beam was designed for 20 minutes, but when you checked the results of every other lab, Well, some of them got 16 minutes, of them got 45. So it's like what mean it's a still beam. I want to say our test results was really nice. We did a paper with colleague Marek Łukomski scheme on that. We our test results with calculation method from Eurocode. We also did a, coupled mechanical analysis, of that beam. And we got same results each time. But some labs got 16 minutes. You wouldn't want to go there obviously. But the ones that got 45, well,

Wojciech: 35:04

fantastic

Piotr Turkowski: 35:05

lab. I mean, I will do all my test there so this is, this was still being a very simple test, the other round Robin was about doors. So that's a way more complex element and it touches two subjects. The first one is that that product hasn't tested before because its classification came exactly from what you've said, from evaluation of a family of products. So they didn't test these doors in particular. They tested some other, and they said, Well, because this and that, this door could be regarded as the same class

Wojciech: 35:42

They look, they look 30 to me

Piotr Turkowski: 35:44

They looked dirty to me, here the spread was insane. It was between few minutes to. 90 or something like that, that, that, virtually makes absolutely no physical sense on how that could happen. even if we exclude a very failed test because of obvious mistakes, you still get a spread of a hundred to 200% of the test results.

Wojciech: 36:13

Yeah. is it 30 plus minus 30?

Piotr Turkowski: 36:15

it's, uh, 30 plus minus 30. Yeah. Something like that, which is what does it say of the product? And the, the, the problem that it also showed much different laboratories read the standard. The standards are maybe 30 pages long, some of them. you can still find, mysteries on how to deal with the pressure, how to deal with the temperature well, to where to put thermos and those mistakes. Maybe, Okay. I don't want to say mistake. Those of what was by some other general interpretation of the standard were so huge that there are courses ongoing right now on there are standards being changed on how to exactly calculate the pressure inside the furnace because it all influences your test results. so at the beginning I said, if you say to me what a fire resistance class is, I will tell you it goes with the test method. But right now you cannot even be sure of that because it also goes with the laboratory behind the test. And this is something that shouldn't happen, but it's something that unfortunately our reality.

Wojciech: 37:25

Oh man, I'm in the head of my listener now who entered this, uh, podcast in expectation to learn what the fire curve is and how much pressure we applied in the furnace. And now we're in the world of, uncertainty in, in experiments that's like a hundred percent scatter. and, and then on the building, the firefighter will tell you, Okay, this is 30 minute door. So they give you exact 30 minutes in, in the fire. and that's what publicity expects. That's what, uh, if there's a major fire, that's what the journalist will be digging into, you know, what was the fire resistance of that door, what classifications they have obtained, and this. I mean, I've expected that, but it's even worse than I thought that, that this, this disjoined of what the test is for us, for manufacturers, for AHJ's and for general public, this is crazy. Uh, you, you maybe remember when we had our paper on fire resistance of, of timber walls in review and, we, we wrote something that the public understanding of the test is, is like this. So we really need to rethink the test to adjust it a little bit. So, so it represents reality better. Their reviewer was like, wouldn't it be easier to just change how people perceive the test? Well, no, that's almost impossible to change the, the perception because we are working here in a very. Small circle of highly specialized people who are literally the only group who understands how it works. And then everyone else from fire engineers to fire scientists have some assumptions or, or presumptions of what we do, what we produce, and, uh, what the behavior of, of the elements is. I think this is a very important, uh, and difficult podcast episode, so thank you. Thank, thank you for sharing all of that.

Piotr Turkowski: 39:17

I, want to look at on, on the bright side of that. don't want to be very difficult.

Wojciech: 39:26

good guys?

Piotr Turkowski: 39:26

Are read the Good Guys. Yeah. Yeah. Sometimes I ask it my myself cause what is the alternative? What is the alternative

Wojciech: 39:34

Yeah. Okay. Yeah. it's chaos. It's chaos. it's even more of what made testing where it is now. It's more of calculations matters more, more of presumptions, more of expectations. What it would look like if it was a different, you know, it's, uh, it's unvalidated modeling. it's reduction of meshes because of computational time. So I achieve my results quicker. It's the desktop studies in the uk that, that's the alternative. So, uh, out of this two worlds, I, I think, uh, highly specialized people, one who understand their craft, because fire testing is a craft, in, in the end. There's a place for fire laboratories for sure. And the, the model worked. Uh, like if you look at the bigger. The model has certainly worked in delivering fire safety to everyone. It's just this few fires that caused massive damage in which fire resistance was misunderstood. Their like the trouble now because overall the model seems to be working fairly well. So maybe, maybe less, uh, negative, view at least for, for once. Yeah.

Piotr Turkowski: 40:37

that, that's definitely the, the, the, the bright side the topic. definitely have way less fires. We definitely have safer buildings. But, it's, but there's a shade on that as well. Well, it comes with a cost. obviously incorporate very, demanding classes from, from many products who incorporate other active, fire prevention systems, uh, sprinklers, fire detection, alarms, stuff like that. Smoke control. So there's a lot. And, and it comes with a cost, obviously it comes with a cost that our do not cost anymore. What they did 50 years ago, they cost way more. Just like with cars, you, we put more and more safety features in them, uh, automation and, and other things that we could live without, but do increase our safety. Maybe. I, I don't know if it's beyond the point we need, maybe there is no value to human life. It's invaluable, basically. It's priceless. Yes. but, but then our car starts to be quite expensive. so our, our buildings and especially tunnels, we, we've discussed many times on how the RWS fire, came to be what it is and how it's now being applied to tunnels which are way taller, you maybe don't have such exposure anymore. But we still do, do act with RWS fire. And think that brings us to, to another topic could be, uh, that we could talk about is what is the standard fire versus the real world fires. Yes.

Wojciech: 42:12

Oh boy. Mm-hmm

Piotr Turkowski: 42:13

indeed. And, how the behavior of material changes because. If the alternative is calculations, and I fully agree with that, and a shift to numerical or AI learning machine learning is,

Wojciech: 42:27

Digital twin is, is an

Piotr Turkowski: 42:29

it will definitely happen.

Wojciech: 42:31

Yeah

Piotr Turkowski: 42:32

how do we predict the behavior of the we use for over century century right now, which is concrete. if you expose concrete to standard fire curve, it will most likely behave like, like you would think it, it would basically though no, nothing will happen or some very superficial sping will occur for the first few minutes of the testing and basically that's it. There will be some moisture the unexposed side and, and, and that's it. But if you put the same slab for hydrocarbon modified fire curve or RWS curve, it can actually explode. I mean, I've seen sping that made the slab jump over the furnace not like few millimeters. It jumped like to the height of my head. I've seen concrete elements exploding and people running away from the furnace because of the falling, because the concrete was pretty stressed. And once the, strand was exposed to heat, it lost it capability to stress the concrete. And suddenly this whole energy released made the, the floor explode, virtually explode. We had that melted our furnace. We had concrete that contained Baum aggregate and we exposed it to RWS Curve. And after the test, we have found out that our new furnace. few months ago, very first test requires, repair that costs, hundreds of thousands of, of euros because the whole lining was covered in melted baled. I thought I will get fired after that, but I didn't. So was way more courageous for, any other test I did in the future because I knew that if that didn't get me fired, nothing is going to.

Wojciech: 44:21

there's still marks on our furnace. If everyone of you is invited to visit a fire testing

Piotr Turkowski: 44:26

10 years later you can still

Wojciech: 44:29

see the marks. They will be there forever.

Piotr Turkowski: 44:33

So yeah, the standard fire curve is a hundred years old. Definitely everything changed since then. our fires are not, Anymore cellulose fire as they're also being We have way more based materials, Plastics. Our, our furniture is plastic. Our clothes plastic, so it, it's a different fire. obviously, the standard curve. I, and I'm telling you that the method comes with it. want to also add one more thing. I want to say that way we measure stuff, In fires and testing on one hand can be so detailed up to a point where it actually doesn't really matter. And on the other hand, we take some things without any with, with that causes the biggest failures of all. So I will, I want to say, give an example for that. On one hand, we do tend to stick with the temperature measurement. We do have huge science for the, the couples, for the plate thermometers on their size, what it's supposed to be. How we neglect the back radiation from the test But at the same time, we actually measure mostly the radiation that go, that goes towards the, the plate roter. But on the other hand, we have this curve and the standard fire curve. Well, you know, way better than me what is its origin and you know how flawed it is in its very core, but we are still using it a hundred years later. So we, we, we do measure the deflection and define the criteria because of that, but at the same time, we measure the integrity by application of cotton path. Yes, that's very scientific mean

Wojciech: 46:27

very scientific cotton path. Yeah.

Piotr Turkowski: 46:29

Well, it's very quality and I, I think that's the part where people are thinking, it's not like, I mean, for sure people are thinking how to improve it, but at the same time, we are stuck at some point.

Wojciech: 46:42

fire testing is necessary. Product ranking is necessary. Product certification is necessary. All these things are necessary, and, I think it would be difficult. To, to, to scratch the concept. I mean, it is, impossible to scratch the concept. We need that. At the same time, what we need is, is a little better understanding that that fire engineering is engineering guys, let's, let's engineer this. Like, I know it's easy when you write a law to stay class. Class goes with the standard that can change five times over the course of a decade. mean, it, it's easy. Maybe it's, maybe it's the way, may, maybe if you think about overall cost of introducing, more sophisticated methods of testing, of validating, maybe actually that's the cheapest and the easiest and the safest way actually may, maybe this, but, but, still, I, I feel an obligation that we try to understand it better. We. Tried to figure out some stuff. And I also feel there is a place for labs like ours in a, in a performance base for engineering world I, I really like, you know, I, I don't like doing tests. I like doing experiments. And I think places like ours is perfect for experimenting, where you don't close yourself in this preconception of what the class is. What are the failure criteria where you can really open your mind and discuss, is this charting on, on this element something dangerous or not? Does this lead to a failure or not? A very recent example where, where, where you can discuss that, think about it and decide whether it is safe or not. I really en enjoy this way of working in the fire lab, however, this is very, very minor part of, of the, the everyday work we do here.

Piotr Turkowski: 48:27

Well said, and I envy you the opportunities you have as a person who doesn't have to deal with these fire recents tests, the standard fire recents test, and you can.

Wojciech: 48:37

Outside of fans. Fans are fans are funny. I could make an episode about fans, which I boy,

Piotr Turkowski: 48:44

Yeah, I accept that. But you have the freedom to experiment, to build any structure you want and to measure you want. And that's what I said at the beginning. The fire resistance is what you think, what you want it to be. You can shape it, you can see you, we will never see on furnaces because of its limitations and because most of our tests are commercial tests, so their basic purpose to place the product on the market. And the manufacturer, sometimes they are, but most of the time they are not, involved in science here. they, they virtually don't care

Wojciech: 49:21

Uh, some of them do. Let, let's give the credit

Piotr Turkowski: 49:23

yes, some of them absolutely do, but generally they don't. Generally they, that their aim is to place the product on the market with parameters, and they're willing to repeat the test. As many times as it's needed to, to achieve it. Sometimes they will some improvements. Sometimes they will just act on. The fact that fire is testing single testing. is no statistics. You do not have to get three samples of the same product, and each one of them has to, achieve a certain, parameters. You, you, you do a single test and there's nothing stopping them from, from exploiting that. sometimes the problems that occur are are very rare and sometimes they are basically mistakes or something that happens once every million years or something like that. I can tell you about the test about, glazed doors where.

Wojciech: 50:13

Okay. Okay, Let, let's finish this depressing episode with a little bit of on, on, on the cost of our clients. But yeah, no names

Piotr Turkowski: 50:22

no names but the, the test was hilarious. there is a test. You, you, you can see yourself seeing, uh, doors with some, uh, site panel and some top panel. They're all made of glass. And the one fact you have to know about glass for it to work is that it has to break in order to expose the gel, which is inside to heat. And then this gel expands and, creates a barrier for, for heat.

Wojciech: 50:50

So for the ones who, uh, are not, in line with, with properties of fire protective glazing is, is literally many layers of glass and there's a gel between them. So once the, some of the glass falls out, gel activates. And this gel is meant to stop the fire, not the glass itself. Yeah

Piotr Turkowski: 51:06

So the glass breaks. The glass breaks and the glass falls. And once in a blue moon, you will see that the glass falls on the handle. we've witnessed such this, the glass fall on the handle. It opened the door and the test was

Wojciech: 51:21

it is, it's a failure. It's

Piotr Turkowski: 51:24

2, 2, 2 minutes into the test. And it's over because, Because first you have a crack, you have a smoke leakage. Well, smoke itself doesn't fail.

Wojciech: 51:33

I mean, you have an open, you have an open door.

Piotr Turkowski: 51:35

you have open doors and whole frame loses is re rigidity. if it wasn't for that, few minutes later, the top panel basically breaks, completely falls off, outside the furnace, and the test is over.

Wojciech: 51:48

I, I I think that's the number one, funniest. We've seen there, there, there were some , like if in furnace testing, it's always exciting when the things break. Uh, the clients have a absolutely opposite point of view. for them is most exciting. What they, things do not break, but, uh, it makes this, this job interesting. Okay. P uh, thank you. Thank you so much for joining me in here. I guess I, uh, I'll be flooded with emails after this episode, uh, with probably some, people very angry at us . However, I think it was important. I, I always thought being open about what we do is the only way how the fire science can move forward. And I really wish we are the good guys trying to do something better. And, if anyone knows how we can do our job better, please tell us. We will very gladly take your advices and, uh, we can also talk so you improve your understanding of our craft and, and what's really happening in the fire lab. That's a perspective that has not been in the podcast yet. And, Piotr thank you so much for, for bringing it

Piotr Turkowski: 52:52

It was a pleasure and I hope, people will, will enjoy this episode.

Wojciech: 52:56

There, there was a lot of doubt in this episode, but in the end it's something that works and we would love to make it work better. And uh, yeah. Com You gave me an idea, you should do the episode long time ago, Compat with Fire versus Standard Curve. Boy, that would be a funny episode. Thanks p and see you around.

Piotr Turkowski: 53:14

you very much and see you all. Thank you. Bye bye.

Wojciech Wegrzynski: 53:18

And as you may have figured it out to him, that's it for today's episode. I hope you enjoyed it. I hope we didn't insult anybody personally. I mean From my own experience, uh, people in, in the fire testing, Industry. I really read people. Good people. We have some systematic challenges to work with. That's for sure. We have. Some competing interests to, to work around. And this brings challenges like the ones that have been discussed in In this episode. I hope the image does not go. Too negative after this. I mean, it's not I just wanted you to understand. Some specific conditions. Some challenges that you may not be exposed to in your everyday work. And that will help you understand better the challenges that we have to go through. And that will let you understand. The meaning behind the indexes a little bit better. And understand the challenges that go with that and understand that. As I said many times fire resistance does not tell you the whole story of fire behavior. It cannot be used. As one soul only proxy of performance of materials, elements in fire. it was never its purpose. Its purpose was. Ranking Classification. Dual something that you can measure and compare against another product. That's, that's the ultimate goal of fire resistance and it should be treated like that. Not as an ultimate proxy of safety. So, yeah. Thank you for staying with us. In this very challenging episode. We had a lot of fun recording this, but trust me, it was a difficult conversation and, uh, yeah, I'm happy. I'm happy. We did And, uh, what, what else I hope to see you here in the next week. Next Wednesday. Another podcast episode, waiting here for Cheers.