We have an exciting two weeks ahead. The research team will be visiting 4 conferences in the coming weeks to present 6 presentations. In addition we will have a 7th presented at ASFE and this will be announced at a later date. The below are brief descriptions of each. Open access versions will appear at a later date.
CSCE Symposium in Vancouver (May 31st to June 3rd)
Mass Heritage Timber Performance in Fire presented by Arlin Otto. The paper looks at a comparison of timber performance in fire of three unique types of timbers. The paper will also discuss adhesive bleeding seen in LVL panels .
Our research team received four NSERC USRA scholarships this summer (up from two last summer). The students (Natalie, Ben, Chloe and Seth) with these scholarships will study a variety of projects from Modelling pedestrian flow, timber design, to studying travelling fires with our international and national collaborators. These national awards at Carleton are given to undergraduate students who are excelling academically and have an interest to pursue further graduate studies.
Our graduate students Hailey Q won an Ontario Graduate Student Award, and so too did Matthew Smith as he recently won the SFPE National Capital Region Chapter Scholarship for Fire Safety Engineering for his thesis and these results are currently being distributed through the Canadian Institute of Steel Construction. In addition Arlin won Provost Scholar. In total the research team received about 36k in scholarships this past month.
Research team member, Matthew Smith, and Engineer at global consulting firm, Entuitive, successfully defended his masters thesis: Towards a Performance-Based Fire Design Framework for Composite Steel Deck Construction in Canada . His thesis and defense were of the highest quality that there were no corrections necessary. Matt was subsequently nominated for the university’s senate medal (he has also just been awarded the SFPE National Capital Region Chapter Scholarship in Fire Safety Engineering in Canada for his work. A big thank you to his examiners whom I would say have a combined experience of over 60 years practicing steel construction. Also a big thank you to project sponsors: CISC and Entuitive, as well as to reps from FM Global and the National Research Council, NIST for their previous feedback and contributions.
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.
We visited NIST last week to discuss human behavior in fire and structural testing on steel structures (ill post later on those stories…). The agenda was quite simple arrive August 16th in the evening, attend a one day visit and return August 18th.
On August 17th at approximately 2 am I was awoken by loud banging on my door. I heard a man yelling ‘you have to get out’. I did not react to this immediately because based on my stay at various hotels in the past ive heard this often by many people banging on doors. Then, the man yelled, that a fire was located in the building (later it was discovered this was actually a gas leak next door). At this point i started to react though very slowly. The alarm sounded. A T-three signal with audio que to leave. Then I really started to react to the point where i was trying to grab everything i could in terms of passport, and wallet. It was easy finding the stairs as everything was illuminated, i wonder what i would have done had things not been so illuminated. It took me id say 30 seconds to act once i realized the situation i was in, and about 2 to 3 minutes to get out of the building (I met my research student in the hall, so i did not need to search). Outside of the building I noticed most people did not have possessions with them ( at least large purses, bags or so). However when allowed to re-enter the building I and at least 10 others were cuing to get cards to get back into the building. I chatted with the staff after the event and they informed me that the staff and the local police ran the evacuation. The seriousness of the situation was made because of a fire about a week before by a gas leak apparently. It was interesting upon reflection because normally a verbal que will push one to leave faster. I was merely conditioned to go slower. But the seriousness of the drill, verbal combined with alarm i believe pushed all people to act quickly to leave. Something to think about more combined with standard theory when my grad course People in Fires meets next spring. Of course we did visit NIST to chat about other research which is best saved for another day.
Had an absolute grand time crushing Legos with Hailey Todd and the virtual ventures summer camp at Carleton University this week. Thought Id pass on some of the results we observed. Unlike the previous study conducted for the BBC where only one Lego block type was tested, we really wanted to understand what happens with Lego under a realistic building configurations and loading scenarios. So we took typical Lego blocks of 1×1, 1×2, 1×3 and 1×4 brick sizes and tested them in a loading actuator with compressive displacement control (mm per minute).
What we observed was that as the size increased so too did the ability to carry load (see graph below). Though it was not proportional to the added stud-brick for each block. We did not cap the Legos because we wanted to see the full effect. Basically the failure mechanism is as follows, the test begins with load being applied and the Lego brick ‘stud’ is pushed into the block giving a flat loading surface along the top of the block, there is a small elastic phase and then we begin to crush the Lego block (its peak load). Later we did cap the Lego and saw some interesting differences in peak load and failure pattern (see below).
We opted to use Lego as a teaching example as its a relatable building material to youths. I think its a gate way to show them just how strong materials are when you can relate them to the day to day lives, obviously we get them hooked there, and progress to crushing concrete and breaking steel much after.
We traveled to Halifax to take part in the Canadian Engineering Education Conference. At the conference we presented a study titled Fire Safety Engineering Education using Experiential Learning by myself and student authors Lauren Folk and Claudia Gaudreault. The presentation described successes of the re-launch of our human behavior in Fires course at Carleton University last Spring. Of emphasis is a high rise evacuation drill the students partook in. The conference was quite eye-opening in that it dealt with how design is to incorporated into the undergraduate curriculum, alot of focus was given to how we can improve enrolements of women in STEM. overall the conference touched on a number of subjects. There were two talks about fire engineering, and a number of discussions which broke out to the state of fire engineering in Canada. The highlights though included the perfect choice of venue, and the number of activities that Halifax had to offer. i was very impressed by the students i met, and hope them the best as they progress through their studies.
Most of the research team will be travelling next to Interflam to present four papers. We will then be visiting Edinburgh, and London. More to come!!!!
Spent the greater part of last weekend attending the CISC (steel construction) Educators forum. Many similarities to the Steel in Fire forum which was back in Europe. It was quite interesting and a really good chance for open dialogue with many industry organisations. Particularly seeing a number of very interesting constructions being made was also fascinating (from bridges, to tall buildings, to even heritage and conservation of buildings). At the meet up I gave a progress presentation regarding efforts in Canada to advance Performance Based Fire Design frameworks focus being on steel construction. The presentation I gave was more for viewing as education and a state of the art of fire engineering for the steel community in Canada. Basically where we are in Canada versus where other countries are with respect to advancements and their research, it was received well though id say with a touch of controversial flare.
Tall Buildings Under Construction
Below is a short photo montage of a composite steel structure as its being built from floors under construction to finished – i think from an educational stand point that is important for students to see the construction, not just write about it or read about it. The pictures first illustrate the construction of the floor from the placement of the beams (trusses in this case), to the placement of the corrugated steel deck; to the placement of the smoothed steel mesh; to the poring of the concrete, before applying fire protection to after; and finally a nearly finished floor:
When finished the structure should be over 50 stories tall. I also included a short rather lengthy video of the forty story freight climb…..
Heritage and Conservation Construction
What I enjoy alot of about teaching at Carleton is learning the programme, its similarities to Europe its differences. One of the biggest challenges for me was to wrap my head around conservation of heritage structures. In Calgary I’d say this was a hot topic. We had a very good example of the integration of a brick joisted 5 story building with a contemporary music centre. One of the unique challenges with that was the occurrence of a flood during preservation of the brick bilding. My favourite part was during the preservation of the facade they uncovered ‘ghost’ signs and preserved these on the face of the building. The contemporary music hall uses a terracotta facade. Construction of this centre is nearly complete.
My fourth year design group is undertaking a prestressed concrete bridge design for havey traffic, the latter part of the trip involved seeing two unique pedestrian bridges which were constructed at a price tag of about 25 million each.
And there you go, a unique engineering trip with lots to show and interesting new meet ups. If only the weather was warmer.
Our new paper, Creep of Prestressing Steels in fire, is now in press in the journal Fire and Materials (you can access it here; an open access version is to come). It is a great piece about prestressing steels used in Post-tensioned structures. We show how high- temperature creep is effected by the chemical composition of the steel. While it may seem obvious to some, the effect this can have for prestressing steel in high temperatures seen in real fires is astounding.
Consider several different prestressing steels, all behaving the same in ambient service temperatures, but when stressed and heated (700 MPa and 427C) as if they were in a fire, one fails after 5 hours, were the others fail below 1.5 hours. All likely due to the chemical composition from the production process of the steel (see the above figure). These tests are described in the paper (that and about 80 others). The same trends shows the same effect in simple strength tests at high temperature.
The paper also describes the use of digital image correlation to measure the strain at high high temperature. An innovated technique, but leading to important insights about true areas and strains as the steel fails in high temperature. A compiled video of a creep test is provided below which illustrates how quickly tertiary (third stage) creep takes effect before failure.
The above video shows the prestressing steel coated in a black and white speckle texture pattern. Image correlation is a powerful technique for measuring high temperature strains. Its a very simple process described below