Transcript
Transcript for In The Woods Episode 59 – Mass Timber: Lessons and Innovations
- 00:00 Introduction to In the Woods Podcast
- 00:40 Meet Dr. Mariapaola Riggio
- 01:13 Sustainability in Timber Buildings
- 03:06 Journey to OSU
- 04:51 Historic Restoration Projects
- 07:36 Research at Peavy Forest Science Center
- 08:46 Monitoring Mass Timber Buildings
- 10:46 Key Lessons and Advice
- 11:41 Engaging with the Research
- 12:32 Lightning Round with Dr. Riggio
- 13:47 Conclusion and Resources
- 15:03 Credits and Acknowledgements
- Top of the Document
Introduction to In the Woods Podcast
[00:00:00] Lauren Grand: From the Oregon State University's Extension Service, you are listening to In the Woods with the Forestry and Natural Resources Program. This podcast brings the forest to listeners by sharing the stories and voices of forest scientists, land managers, and enthusiastic members of the public. Each episode, we will bring you research and science based information that aims to offer some insight into what we know and are still learning about forest science and management.
Stick around to discover a new topic related to forests on each episode.
[00:00:32] Scott Leavengood: Welcome back to the In the Woods Podcast, presented by the Forestry and Natural Resources Extension Program at Oregon State University.
Meet Dr. Mariapaola Riggio
[00:00:40] Scott Leavengood: I'm Scott Leavengood, extension specialist in wood products, and I have the pleasure of talking with Dr. Mariapaola Riggio, one of my colleagues at OSU. Let's start with a quick introduction.
Mariapaola, your official job title on our College of Forestry website is Associate Professor of Wood Design and Architecture, and Richardson Chair in Wood Sciences and Forest Products in the College of Forestry at Oregon State. But what do you tell people outside of the workplace when they ask you, what do you do?
[00:01:12] Dr. Mariapaola Riggio: Hmm.
Sustainability in Timber Buildings
[00:01:13] Dr. Mariapaola Riggio: Well, outside and inside of my workplace, I tell them that I research methods to enhance the sustainability of the built environment by addressing environmental impacts across different stages of a building lifecycle. This includes optimizing material sourcing and use such as exploring the efficient application of the utilized with species in construction, as well as investigating end of life strategies that.
Go beyond disposal and end fielding, for instance, reusing building components. But the central part of my work is focused on extending the service life of timber buildings as longevity reduces the need for frequent new construction and also minimizes construction waste. Additionally, by maintaining timber infrastructures for extended periods we delayed the release of sequestered carbon and so we further contribute to climate mitigation efforts.
In my research on mass timber construction really falls under this broader framework. For those who don't know, mass timber consists of large scale engineered products used for structural components such as floors and walls, and they offer lower carbon alternative to materials such as steel and concrete.
And so, you know, the benefits of mass timber stems both from the fact that they're renewable, from renewable sources, and they can be produced with lower carbon manufacturing processes, but also from their capacity to store carbon. If, if we can store this carbon for a longer period of time, then we can, you know, better realize the environmental advantages of these products.
[00:03:05] Scott Leavengood: Great. Yeah. Thank you.
Journey to OSU
[00:03:06] Scott Leavengood: And since you and I have worked together for a number of years now, I know you received your degrees in, in architecture and structural engineering in your home country of Italy. What, what brought you to OSU to work in the wood science department here?
[00:03:20] Dr. Mariapaola Riggio: Yeah, so as I said I.
Quite interest in extending a building's lifespan, and this passion stems from my early fascination with cultural heritage preservation. I will always been captivated by how centuries old buildings have with withstood the test of time and understanding the principles behind their longevity has been a driving force in my work.
And this fascination began during my time as an architecture student in Florence. Which is home to one of the worst, most renowned restoration schools. I was fortunate to work on my master thesis under the guidance of one of the leading experts in, uh, timber building restoration. And he had both an engineering and architecture background, so I could really appreciate, uh, how this inter twin skills shaped this approach to restoration.
So after seven years as a practitioner, I decided to return to school to pursue a PA PhD in structural engineering, and I joined the Timber Engineering Research group at the University of Trent. Which is one of the leader in Europe. And this provided a unique opportunity to deepen my expertise in the field.
And then as a PhD postdoc at the University of Trenton, later as a researcher at the National Research Center of Italy, I had the opportunity to explore wood as a material and, uh, collaborate with numerous wood scientists. So when I learned about the job position at OSU, I saw it as the most natural next step in my career.
Historic Restoration Projects
[00:04:51] Scott Leavengood: You mentioned that you know, working on some of these centuries old structures, and I've heard you talk about some of those what was one of the most interesting projects that, with which you've been involved?
[00:05:03] Dr. Mariapaola Riggio: Well, it's one of those. So before, before moving to the US I was involved in a large scale effort on, um, top spell tower in Florence.
I, I don't know, maybe, maybe many have the, you know, this view of the, one of the monumental complex in Florence, uh, with the. Bell tower with colorful marbles close to the cathedral. It's, uh, one of the prime examples of the, of 14th century gothic architecture. I. And my role focused on conducting a structural, a assessment of the timber roof.
So the roof is visited by hundreds of tourists daily, even if it's not part of the typical postcard. But you know, after climbing more than 400 steps, they are rewarded with a breath, a breathtaking panoramic view of the city from the rooftop terrace, and one of the roof rafters had failed, and it was crucial to assess the severity of the damage.
So the talent, one of the challenges was that the flow of tourists couldn't be interrupted. So I had to work with visitors all around me, and I was using all my specialized instruments and sensors to collect various data to assess the extent of biodegradation and other forms of damage. But even more important than, you know, any specialized instrument, I was performing a very careful visual inspection, which was.
Key to reveal the cause of damage. So now think at the, so the roof is a wooden structure that converges at the center where it supports a huge flagpole. It's a 50 feet high red cypress tree. I. Witha golden ball containing relics and a cross. So over time, the tilting of the ball and its pressure on one side of the roof caused a series of displacement within the structure and the roofings system.
This led to discontinuities in the waterproof barrier, allowing motional ingress and resulting in the decay of some of the timber members. So it was clear that previous interventions tried to fix the symptoms. Without effectively addressing the cause of the damage.
[00:07:20] Scott Leavengood: Yeah. Okay. That does sound, sounds fas and, and the fascinating, but also the challenges of working with Yeah.
With, with the crowd. And you became a tourist attraction it sounds like.
[00:07:30] Dr. Mariapaola Riggio: Yeah.
[00:07:32] Scott Leavengood: Yeah. A bit less so here in the college, but you do have some work here that's pretty visible as well.
Research at Peavy Forest Science Center
[00:07:36] Scott Leavengood: So let's talk a bit about your, your ongoing research in the new PV Forest Science Center in osu College of Forestry. What is, what does the project involve and, and how do you, how do you see it relates to your previous experiences with assessment of historical buildings?
[00:07:54] Dr. Mariapaola Riggio: The monitoring project in the PB four Science Center is a large scale initiative focused on, uh, collecting and analyzing data towards various parameters to assess the building performance over the building service life. So, while in my previous experience with historical buildings, I was called in when the passion was already ill.
To diagnose the severity and cause of the issue, imagine that in the case of pv, I'm monitoring the condition of a young, healthy subject, ensuring it remains in the, in optimal condition and performs as intended.
[00:08:34] Scott Leavengood: How much better to start before there's problems. Right. Exactly. Know what to monitor before it's, it's already a structural problem.
So what, what sort of things are you monitoring in PV and how
Monitoring Mass Timber Buildings
[00:08:46] Dr. Mariapaola Riggio: So we are deploying over 350 sensors. To measure moisture content, relative humidity, temperature, displacement forces, and accelerations in, uh, critical areas of the building. This includes, selected roof locations representing vulnerable details.
we are, measuring deflections of the CLT concrete composite floors. we are, , monitoring the post tension, the rocking sheer walls. , so tension losses, but also other parameters that are related to tension losses in this unique, , seismic system featured in the building.
[00:09:26] Scott Leavengood: Right.
Why is that work important? Or maybe another way of asking the question is, are there unique considerations for mass timber buildings?
[00:09:34] Dr. Mariapaola Riggio: Well, I think this data is vital for both industry and academia. it provides insight into, the actual behavior of this new mass timber system used in the building for a.
Um, a long period of time. So it validates design assumptions and also enables proactive interventions if deviations occur. Uh, additionally, the data is used to validate engineering models, helping to develop more accurate predictive tools. So for instance, the seismic performance of the post tension rocking sheer walls, it depends on the ability of these walls to absorb earthquake energy, return to the original upright position.
And this behavior lies on the tension in force and the steel tendons embedded within the COT wall panels. So if this force decreases too much over time, it may, you know, basically impair this behavior and then can cause residual rotation in the walls, maybe damage both structure and non-structural components compromising the resilience of the building that is one of the fundamental features of its design.
[00:10:41] Scott Leavengood: Hmm mm-hmm. And what have you learned about Peavy so far?
Key Lessons and Advice
[00:10:46] Scott Leavengood: What advice would you give to architects and engineers that are designing similar mass timber structures?
[00:10:52] Dr. Mariapaola Riggio: Yeah, , some key lessons include designing for durability across the various stages of a project.
So, for example, developing details that prevent moisture traps, not only during the building series left, but also during construction. Or creating details that allow easy access to parts that require maintenance repair. So basically designing also for maintenance. and this approach has been systematically implemented in, uh, exemplary timber structures of the past, for instance, by incorporating sacrificial elements that protect more critical structural components that can be more easily replaced. This concept is especially important for mass timber buildings as they consist of this large integrated structural systems.
Engaging with the Research
[00:11:41] Scott Leavengood: many of the things you've talked about here are incredibly visually interesting as well.
Is there a way that listeners of in the woods can see these sensors and learn about the project firsthand?
[00:11:52] Dr. Mariapaola Riggio: Well, first off, you can come and visit us on campus. We have, left exposed all the sensors in the east stairwell to demonstrate the application on one of the sheer walls.
And in collaboration with science communication experts and the college communication team, we have developed an educational display. Additionally, we are curating the collected data and publishing it in open access repository. So if you're interested in the data we have already all the, the data from the construction phase that is available to the public.
And we are in the process of releasing data collected over the past five years.
[00:12:30] Scott Leavengood: Five years, right. Fantastic. All right.
Lightning Round with Dr. Riggio
[00:12:32] Scott Leavengood: Well, before we wrap up this episode, I have a few more questions for you in what we call the lightning round that accompanies every episode.
And the first question is always, what is your favorite tree species?
[00:12:50] Dr. Mariapaola Riggio: Hmm. So, uh, not only the trees, but in general, the Mediterranean scrub reminds me of my childhood. Mm-hmm. So I guess if I have to choose a tree, olive trees,
[00:13:04] Scott Leavengood: , olive tree. Okay. And then what's a unique tool that you use that helps you with your work?
[00:13:12] Dr. Mariapaola Riggio: Okay, let's see if you can guess. It has two prongs and is used to find moisture, but it's not a divinous rod, so.
[00:13:21] Scott Leavengood: Right, right. Yeah. I think any of us that are wood scientists spend a lot of time with a moisture sensor. Uh,
[00:13:28] Dr. Mariapaola Riggio: yeah. Uh,
[00:13:29] Scott Leavengood: like that. So, and as you say, . Critical tool for assessing structures, whether new or ancient. So a moisture meter. Right?
[00:13:38] Dr. Mariapaola Riggio: Exactly. So yeah, I don't want to go into a full lesson in the relationship between wood and water.
[00:13:43] Scott Leavengood: Right. That'll be the next episode.
Conclusion and Resources
[00:13:47] Scott Leavengood: Maybe, , finally here, what other resources can you share for a listener that would like to learn more about your research? I think you talked about it already. There'll be some open access availability for the data, but yeah.
[00:13:59] Dr. Mariapaola Riggio: So during the spring 2020 term, , so amid the Covid Pandemic, the College of Forestry hosted a stay at home lecture series and professors, students and researchers shared their work and a variety of topics and issues.
And the lectures were open to the public and are all still available online on the college website. So if you're interested in learning more about our project at Peavy, I invite you to watch the recorded talk. The title is A Living Lab at Peavy Hall, lessons for the Mass Timber Construction Industry.
[00:14:32] Scott Leavengood: Okay.
Well, I'll make sure that when we get this posted on the, the website that those links are provided along with the picture of your moisture meter there. Yeah. And an olive tree. Well, Dr. Riggio, thank you so much for spending some time with me today and for sharing your knowledge with our listeners.
[00:14:48] Dr. Mariapaola Riggio: Yeah.
Thank you for having me.
[00:14:50] Scott Leavengood: Yeah, it's been a pleasure. Well, this concludes another episode of OSU Forestry and Natural Resource Extensions in the Woods Podcast series. Thanks for listening, and don't forget to subscribe.
[00:15:01] Dr. Mariapaola Riggio: Bye
Credits and Acknowledgements
[00:15:03] Lauren Grand: The In the Woods podcast is produced by Lauren Grand, Jacob Putney, and Scott Levengood, who are all members of the Oregon State University Forestry and Natural Resources Extension team. Other members of the team who've been involved in the podcast include Carrie Berger, Jason O'Brien, and Stephen Fitzgerald.
Episodes are edited and produced by Carrie Cantrell. Music for In the Woods was composed by Jeffrey Hino, and graphic design was created by Christina Fryhoff. Funding for In the Woods. is provided by Oregon State University Forestry and Natural Resources Extension, the Oregon Forest Resources Institute, and the USDA Renewable Resources Extension Act funding.
We hope you enjoyed the episode and we can't wait to talk to you again next month. Until then, what's in your woods?
This episode features Scott Leavengood interviewing Dr. Mariapaola Riggio, an expert in wood design and architecture. Dr. Riggio discusses her work on enhancing the sustainability of mass timber construction and the benefits of extending the service life of timber buildings, sharing insights from her research on optimizing material use and end-of-life strategies, as well as her past projects in Italy, including the structural assessment of the timber roof of the bell tower in Florence.
