At York University, our fire research team studies heritage materials and their response to fire. Our focus has been to consider timber and masonry. Doing these studies we are in the midst of preparing revised international guidance for these important structures. More recently the events in Paris have emphasized why this is such a serious topic of research to consider. For the last two years we have focused our efforts to really understanding timber performance, and we have done this by procuring real materials (columns, beams etc) from structures undergoing renovation (adaptive re-use) or sadly demolition. The importance of this study is now even more profound given this weeks events.
Our Timber research was recently published in a conference paper presented at ASFE. The paper that describes our team’s work before 2016 can be downloaded here.
Since that above paper, and last year, our research team have undertaken four new and novel Timber based projects to expand knowledge in this research area as we relocate to York University.
Very exciting to announce that effective this year I am joining John Wiley’s journal, Fire and Materials as an Associate Editor. In this role I will be considering mainly the structural materials papers. Fire and Materials is one of the more older peer reviewed journals for our research community beginning in 1976. The journal is led by Steven Grayson. More information is to come on this initiative. For now be sure to check out my own Fire and Materials paper on the Creep of Prestressing steel which can be downloaded here .
On April 22nd, as part of a break from school at the end of the term, I took in the 911 Memorial Museum in New York. Not the most uplifting story to hear on a vacation, but a place I have been meaning to visit for years. I felt the museum to be very tasteful and a very important learning piece for those to learn what exactly happened that day (but ill argue understanding is different word to use here and a word I do not think we ever will be able to associate to that day). I feel it so important that people do be aware, today’s students that i teach, were far to young to know a world pre 911, they grew up in a different world. And from that the observations that you can learn visiting are just so much more important. The museum allows you to see quite a bit in terms of artifacts (fire trucks, and even the original foundations of the the tower). But it does educate what happened.
The Salesforce Tower will soon be completed and overtake the Pyramid as San Francisco’s newest and tallest building. I had a great oppertuinity to take a stroll through the construction area early this month and decided to highlight a few aspects of what i learnt and saw.
To me when i see cities like this, i am filled with creative inspiration. Its very easy to predict what the future skyline of San Francisco will look like. Where the tall buildings will appear (note that for now special planning approval must be given in San Fran), where the heritage will be conserved etc.
Its been about 15 years since the events of September 11th. I remember the day very clearly still. Reflecting on how much has changed since that day in society and our built environment is staggering. While visiting NIST this summer I had the opportunity to do some of this reflection. Largely a lot of the structural work being done there is to aim to improve the safety of our buildings. Outside their new fire lab they have preserved steel pieces from that day in a memorial. If you want to read more about the structural and human behavioral analysis of the events from that day the journal Fire Technology has a really comprehensive issue from 2013 which is a very enlightening read.
The MGM Grand Fire occurred on November 21st 1980. It represents a significant case study in the study of Human Behavior in fire as well as for smoke dynamics. About 87 people were killed in this fire. Recently I had a chance to visit and talk to certain staff members at the current building over 35 years later. There are many rumors associated to the fire today but I thought a visual representation is quite telling when you compare the building to other hotels on the strip in Las Vegas. Most people are completely unaware that the building is still standing today.
Ive included some more recent photos herein. To many who visit the current building there is not much remembrance to the fire that is obvious to the casual pedestrian walking by. If you search really hard there really isn’t a plaque talking about the fire that is visible. However there are many reminders present if you look carefully as the included imagery resonates. The patrons are oblivious to what happened for the most part., although some online do contend the buildings haunting and unusual activities – though i dont advise talking about these stories within the building or near by as many are sensitive to these types of stories. Images posted for reflection to those keen on our disciplines history.
Ill talk more on this at a later date.
The research team recently traveled to the United Kingdom. Students (three of them + one former) presented 4 papers with me. Their work was on aging populations, engineered timber, concrete structures after fire, and advancing our knowledge in fibre reinforced polymer constructions at the Interflam conference. All the papers were well received. Our human behavior in fire paper can be downloaded off research gate here. Beyond this conference the students joining (three of them) had the opportunity to visit Arup’s London office for two days and the University of Edinburgh for a day.
This trip has become a staple on my research team. We also did this trip in 2015. Reflecting on the last experience, I felt that the trip was too short and did not have enough exposure to contemporary design. In that sense this years trip (with the thanks to the good folks at Arup in London and Edinburgh Uni) expanded on this experiential learning trip. The theme of the trip is the interaction between research and consultancy design practice. The trip’s itinerary to the United Kingdom included the following: Interflam Conference from July 4th through 6th; on the 7th a visit to Arup London (where three design projects were reviewed with the students as well as a nice presentation given by myself to the Arup structural skills team); On the 8th the students traveled to Edinburgh University to tour the fire facilities and meet their research team. Afterwards on the 9th, the students had an opportunity to take in the number of heritage structures in Edinburgh as well as visit the Edinburgh Fire Muesuem (see previous post – the museum may be permanetly closing soon). On the 11th of July, the students visited the iconic structures of London. We started with the Grade I heritage LLoyd’s building (yes it is heritage…..) to vsiting the Shard (pictured). The Carbuncle Cup winner the FryScraper was also visited (we also saw the Razor 2010’s winner also called the Strata). On the 12th, the students
visited Arup once again for a day on Human Behaviour in Fire (also to consider many heritage structures). This included two project reviews and a site tour of the Tate Modern. The students gave a presentation on their Human Behaviour in Fire and Engineered Timber work. This was a great experience for them as they got to present to engineers from offices in China, Uk and North America via a conference. On the 13th the students returned home. It was awesome the amount of time provided to the students at Arup and Edinburgh – thank you to those awesome people!
So often in research students tackle ‘pie in the sky research projects’ which are dissociated to growing our immediate capabilities to better design our existing and planned infrastructure. The dis-association between research and consultancy is severe in some cases and a communication barrier is often present. We need to get students out there to see whats being built, meet people who are building, see what these engineers need. We need not just motivate students – we need to inspire them that they can make an impact.
A new book will be published by Springer titled; Structural Fire Performance of Contemporary Post-tensioned Concrete Construction. The book is available now. You can now order or download it here . The book features:
- A follow up to my highly cited Fire Safety Journal 2011 literary review paper – doubling the amount of tests analyzed;
- New insights on bonded post-tensioned concrete construction;
- Concise account of three large scale multi span post-tensioned concrete floor high temperature tests;
- Updated five phased deflection theory on post-tensioned concrete continuous members in fire; and
- New evidence regarding the origins of the standard fire test and discussion regarding that test’s relevancy to unbonded post-tensioned concrete construction.
The book aims to provide raw and valuable test data (restraint, tendon stress, slab temperatures, deflection etc.) from the three large scale tests fire tests on post-tensioned concrete. This information will be useful for structural design firms and researchers interested in understanding concrete structural systems in fire.
Developed based on my internationally recognized doctoral thesis (improving and expanding on portions from: chapter 2 – literary review and chapter 5- large scale testing of concrete slabs), the book represents a balanced and essential overview of the subject. Other chapters and portions of that thesis are being developed for publication elsewhere (future post to come).
The book was copy-edited by a communications intern on my research team and co-authored by the University of Edinburgh’s Luke Bisby. Our goal was to create a highly accessible book for entry undergrad students to senior engineers.
Every year candle fires can be attributed to over 100 civilian deaths, as well as nearly 900 fire fighter injuries. They represent nearly 4% of civilian home fire deaths (NFPA stats). Candles are by far a serious and not to be misunderstood beast. On the days after where many observed Earth Hour, thousands would have lit these beasts, and many just might not understand the complexity behind them.
The complexity of a lit candle is profound when you think about it, and its natural to understand why they can cause so much damage when you understand what the science is behind a lit candle. I find that they are useful teaching aids to illustrate the complexity of a flame. So this entry today explores this science in a really basic way (but more so that you the reader do not explore this on your own and become part of the above statistic).
Lets consider an ordinary candle. The candle includes a simple wick at the center surrounded by (parraffin) wax. When the candle is lit by a match, it sets off a complex number of reactions which produce a visible ‘fire’ that appears ‘clinging’ to the top of the wick.
Candles have been studied for centuries, and profoundly by individuals such as Michael Faraday (see my recent paper which discusses him). I love the quote provided by Crookes to the start of Faraday’s six lecture Chemical History of a Candle book;
“…Surely, among the millions of fire-worshippers and fire-users who have passed away in earlier ages, some have pondered over the mystery of fire; perhaps some clear minds have guessed shrewdly near the truth. Think of the time people have lived in hopeless ignorance: think that only during a period which might be spanned by the life of one, has the truth been known “
I think its profound when you apply it to even our fire engineering practice today and the amount of knowledge generated in the last 60 or 70 years of fire dynamics. Even though it was intended to be apply to the Victorian mind. But Faraday was onto describing (rather teaching in an effective way) science behind fire.
For instance if you were to estimate the temperatures of the visible flame with the candle, what would you think the temperatures are? If you crudely use a thermocouple to measure temperature, you see well over 1000C near the candle’s perimeter. If you are careful, you may also observe a temperature dip near the center of the ‘flame’. More strikingly (if your eyes do not blind from the brightness – like mine do when studying flames), you can see distinct regions in of different ‘colors’ or rather ‘luminescence’ of the flame. Maybe above the candle you may see some ‘smoke’. And if you lit it for a festive occasion (upon which house fires caused by candles are most predominate) you may question what is causing all of these ‘behaviors’.
When one ‘lights’ a candle you melt the wax on the surface of the wick and also near the base of the wick. The wax becomes a liquid and eventually gets hot enough that it becomes a gas. The gas emitted mixes with the surrounding oxygen. Your heat source ‘ignites’ this gas. While this is on going, the wick, through a ‘straw like’ capillary action, draws up more molten wax, which turns to vapor and continues the combustion process. Fueled by an abundant amount of oxygen at the base of the flame and perimeter, you typically see a blue hue, or very dark black hue. Its an efficient combustion there. The wax is mostly breaking down into carbon dioxide and water. But above that dark hue of a flame, is a bright yellow redish zone. That flame is a sign that soot is being created, emitting visible light. On the outside of the flame you get a very efficient combustion process as you have a good amount of oxygen, but as you move into the visible flame, there is less oxygen available and the reaction is limited by the amount of oxygen that can diffuse into the flame. Even more so, the wick as these processes continue – bends – rather curls. As the wick bends its tip emerges to the outside of the flame where it now receives abundant amounts of oxygen. It too begins to degrade and the wick length becomes controlled (self regulating) in the flame.
Of course my above remarks are so “watered down” to the complexity of just what science and chemistry is going on here in a candle and one could argue my observations are so simplified that they don’t even come close to describing the science which is going on in the candle as it burns off its waxy fuel.
I think one of the interesting observations of a candle is to actually blow it out and then heat the smoke that emerges above (dont try this at home). The result is the ‘smoke’ is none other that the fuel (gas wax) mixed with oxygen, which when conditions are just right with an introduction to flame, can re-ignite the wick of the candle (see my above video – so you do not need to try this). As Faraday began his lectures most appropriately:
“There is no more open door by which you can enter into the study of natural philosophy than by considering the physical phenomenon of a candle”.
And I believe that to be true.
Of course I also believe, that if one cannot understand or rather acknowledge the complexities associated with a simple candle – how can one hope to understand the complexities of a fire in a house or even a building which is infinitesimally more complex?