Progress 03/01/18 to 02/28/23
Outputs
Target Audience:The main target audience comprises of mass timber manufacturers, engineers, and designers. Academia, industry, and code officials were reached through various dissemination and tenchnology transfer activities. The work performed will inform the target audience about the effects of moisture and fungal degradation on CLT connection systems ovr time. Additionally, drying protocols were established for dehumidifying CLT buildings after construction so that there is minimal impact on connection attributes. The findings of the work performed on non0destructive evaluationwill inform the target audiences of the applications and limitations of non-destructive testing (NDT) techniques for the in-situ in-service detection of features within a mass timber member such as steel anchors, air voids, rot, and wet regions, contained in mass timber products with a focus on cross-laminated timber (CLT) panels. Changes/Problems:The changes were forced upon us due to COVID related restrictions and lockdown where access to laboratory and other critical facilities were significalty limited between March 2022- August 2021. Consequently, biological degradation study for the CLT connections were significanlty delayed and had to be restarted. As a result, the full-scale wal tests has been significantly delayed and are being conducted after the project time period has ended. These tests are on-going (Summer of 2023) and will be reported and disseminated as results come in. What opportunities for training and professional development has the project provided?The project supported 2 graduate students (one MS, one PhD) at Oregon State University. Along with the gradaute students several undergradaute student for underrepresented communities (one African American, one first generation college, 2 high scholl interns, one returning veteran).The project partially supported one undergraduate student (female) and two graduate students (one male, one female) to aid in the project. The involvement in the project gave the students an opportunity to perform research under the guidance of the PI at PSU and disseminate their findings in publications. Graduate and undergraduate students participated in the following conferences and symposia: International Mass TImber Conference 2022, 2023 SWST International Convention - 2021, 2022, 2023 Forest Products Society International Convention - 2021, 2023 TallWood Research Symposium - 2019, 2020, 2022 How have the results been disseminated to communities of interest?Dissemination efforts to the Communities of Interests has been through presentations, peer-reviewed articles, student thesis and dissertation (publically available), Mass Timber meet up, seminars at University and other research settings. Compiled data set and engineering models are available through a repository for anyone to use. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
The specific goals of the projects were fully accomplished. Moisture intrusion was monitored on samples and qualitatively documented. Drying regimes were evaluated and the regimes with minial effects to visual and structural properties of CLT and its connections were identified. This drying regime is mild and can be used in the industry with confidence by architects and contractors. Using a set of destructive and non-destructive techniques connection properties were characterized within the CLT elements.A comprehensive literature review was performed to study which non-destructive testing (NDT) techniques could be useful in detecting certain features within mass timber members and connections. Based on the review, ground penetrating radar (GPR) and ultrasonic echo array (UEA) testing were found to be the most promising techniques that can be applied in-situ in-service and that do not necessitate special precautions such as the ones required for X-Ray testing. Applying imaging algorithms to the GPR and UEA measurements was found to be the most promising data analysis technique and algorithms were developed based on the synthetic aperture focusing technique (SAFT) and referred to as extended total focusing method (XTFM). The same algorithm can create 2D images corresponding to a cross-sectional view from both techniques. The algorithms were applied in the laboratory on both solid wood and mass timber samples and evaluated. Different scenarios were studied to evaluate each techniques' ability to detect and quantify features within the panels such as sample thickness, air voids, rot, wet regions, and steel anchors. Using destructive testing program, a temporal degradation of strenght in presence of moisture and degrading fungi was established. Using regression analysis as well as established engineering models such as Seismic analysis of shear walls (SAWS) and trilinear model within ASCE 41, predictive models were developed and calibrated for connection degradation of CLT. THese models were thenvalidated using independent datasets. The degradation was studied for the four major species groups that CLT manufacturer uses accross the world - Douglas-Fir, Spruce-Pine-Fir, Southern Pine, and Norway Spruce. Effect of species on connection properties along with its interactions with moisture intrusion and fungal degradation provides complexity ot the models. Through this project a one of its kind, comprehensive data set was generated for four major species of CLT and how they react under extruniating moisture and biological conditions. This data and subsequent models are valuable to the engineering, design, and forensic communities as they can guide decisions regarding buiding component rehabilitation and replacement. ore over the data can be an input for the material model to capture moisture and biological degradation in the connection system.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Bora, S., Sinha, A., and Barbosa, A.R. (2022). Effect of Short-Term Simulated Rain Exposure on the Performance of Cross-Laminated Timber Angle Bracket Connections. Journal of Architectural Engineering, 28 (4). 04022025.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2023
Citation:
Udele, K. (2023). Biological Durability of Cross Laminated Timber Connections. PhD Dissertation, Oregon State University.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2024
Citation:
Udele, K., Morrell, J.J. and Sinha, A. Effect of drying regime on CLT connection performance. Journal of Building Engineering.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2024
Citation:
Pahnabi, Narges; Schumacher, Thomas; Sinha, Arijit. Imaging of Structural and Mass Timber based on in-situ Radar and Ultrasonic Wave Measurements: A Review of the State-of-the-Art. submitted to Sensors.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2024
Citation:
Udele, K., Morrell, J.J., Sinha, A. Effect of fungal degradation on CLT angle bracket connections. Journal of Materials in Civil Engineering.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Bora, S., Sinha, A. and Barbosa, A. (2019). Effect of moisture on CLT connection properties. Presentation in SWST International Convention, October, 2019, California.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Cappellazzi J, Konkler MJ, Sinha A, Morrell JJ (2020) Potential for decay in mass timber elements: A review of the risks and identifying possible solutions. Wood Mater Sci Eng, 15(6): 351-360.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Sinha, A., Udele, K.E., Cappellazzi, J. and Morrell, J.J. (2020).A method to Characterize Biological Degradation of Mass Timber Connections. Wood and Fiber Science. 52(4), 419-430.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Udele, K.E., Morrell, J.J. and Sinha, A. (2021). Biological Durability of Cross-Laminated Timber - The State of Things. Forest Products Journal. 71(2), 124-132
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2020
Citation:
Bora, S.S. (2020). Effects of Moisture Intrusion on the Performance of a Cross-Laminated Timber (CLT) Angle Bracket Connection. MS Thesis. Oregon State University, Corvallis, OR. USA.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Bora, S., Sinha, A., and Barbosa, A.R. (2021). Effect of Wetting and Redrying on Performance of Cross-Laminated Timber Angle Bracket Connection. Journal of Structural Engineering. 147 (9). 04021121.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Udele, K., Morrell, J.J. and Sinha, A. (2021). Connection Performance in Decayed Cross Laminated Timber Members. SWST International Convention, Flagstaff, AZ, USA. August 1-6, 2021
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Udele, K., Morrell, J.J. and Sinha, A. (2022). Decayed Cross Laminated Timber Connection Systems. SWST International Convention, Kingscliff, Australia.
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Progress 03/01/21 to 02/28/22
Outputs
Target Audience:Academia, industry, and code officials were reached through various dissemination and tenchnology transfer activities. Changes/Problems:The changes were forced upon us due to COVID related restrictions and lockdown where access to laboratory and other critical facilities were significalty limited. Consequently, biological degradation study for the CLT connections were significanlty delayed and had to be restarted. Similarly, the large-scale tests were plaaned for the last year of the project has been delayed as they are dependent on the results from smaller-scale testing. Collaboration with Portland State University was also on hold as lab access at both places were highly restrictive. The collaboration for validation of the algorithm has resumed and will be completed when large-scale tests are performed.The project objectives and approach remains the same as they are vital to the success of the project. However, the project in general, is substantially delayed due to loss of experiments, which had to be restarted. What opportunities for training and professional development has the project provided?One gradaute student participated in Society of Wood Science International Convention held in Flagstaff, Arizona. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?The biological study is underway and results will be available from biological degradation study on CLT connections for the four species studied. A comprehensive data set will be generated that wil be the basis of several per-reviewed publications. Additionally, we plan to evaluate larger walls and structural components. This will also provide us an opportunity to continueevaluating the developed algorithms on small- and large-scale mass timber panels and systems with known geometries.
Impacts
What was accomplished under these goals?
After recovering from the affects of COVID-19 related shutdown, this reporting period was concentrated mostly on restarting the biological degradation experiments. At the same time, PIs were involved in reviewing biological degradation work around the world and summarizing it in form of a peer-reviewed article. The biological experiments are running again, albeit delayed due to unforeseen circumstances, and will have a comprehensive set of data set from that in the next reporting period. The moisture degradation work on connections has been completed and available to the public at large in form of a student thesis and one peer-reviewed publication. Another journal publication is expected shortly from the moisture related work.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Udele, K., Morrell, J.J. and Sinha, A. (2021). Biological Durability of Cross Laminated Timber - State of Things. Forest Products Journal. 71 (2), 124-132.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Bora, S., Sinha, A., and Barbosa, A.R. (2021). Effect of Wetting and Redrying on Performance of Cross-Laminated Timber Angle Bracket Connection. Journal of Structural Engineering. 147 (9). 04021121.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Udele, K., Morrell, J.J. and Sinha, A. (2021). Connection Performance in Decayed Cross Laminated Timber Members. SWST International Convention, Flagstaff, AZ, USA. August 1-6, 2021
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Progress 03/01/20 to 02/28/21
Outputs
Target Audience:Two peer-reviewed publication and a thesis is available for public-at-large. The target audience are engineers, architects, code officials, and other academics. Changes/Problems:The changes were forced upon us due to COVID related restrictions and lockdown where access to laboratory and other critical facilities were significalty limited. Consequently, biological degradation study for the CLT connections were significanlty delayed. Although they were commenced, they were several weeks delayed. Collaboration with Portland State University was also on hold as lab access at both places were highly restrictive. The collaboration for validation of the algorithm for non-destructive evaluation will be resumed once a semblance of normalcy return. The project objectives and approach remains the same as they are vital to the success of the project. However, the project in general, is substantially delayed. What opportunities for training and professional development has the project provided?One gradaute student participated in Society of Wood Science International COnvention - held virtually this year due to the pandemic. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals? In the next reporting period, we will conclude the moisture study on the large-scale CLT walls of four major species. The biological study is underway and results will be available from biological degradation study on CLT connections for the four species studied.Additionally, we plan to keep on evaluatingthe developed algorithms on small- and large-scale mass timber panels and systems with known geometries and inclusions as well as simulated damage.
Impacts
What was accomplished under these goals?
This reporting period was entirely overshadowed by COVID-19 pandemic related lockdowns and restrictions. Due to limited access to laboratory and other critical facility, progress was halted. The moisture study on small-scale connectors have been concluded and the results are disseminated in form a student thesis and is available through OSU's Scholars Archive. Due to restrictions the bilogical study has been significantly delayed. The study has commenced and the first data set will be generated in the next reporting period. However, the PIs were instrumental in formulating, developing, and communicating a method to evaluate biological degradation for mass timber elements. The intention is for other research group adopt the methodology across the US and the world since there are no such methodology available. Once adopted widely, the results generated using the proposed methods can be compared easily to one another.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Cappellazzi J, Konkler MJ, Sinha A, Morrell JJ (2020) Potential for decay in mass timber elements: A review of the risks and identifying possible solutions. Wood Mater Sci Eng, 15(6): 351-360.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Sinha, A., Udele, K.E., Cappellazzi, J. and Morrell, J.J. (2020).A method to Characterize Biological Degradation of Mass Timber Connections. Wood and Fiber Science. 52(4), 419-430.
- Type:
Journal Articles
Status:
Accepted
Year Published:
2021
Citation:
Udele, K.E., Morrell, J.J. and Sinha, A. (2021). Biological Durability of Cross-Laminated Timber - The State of Things. Forest Products Journal.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2020
Citation:
Bora, S.S. (2000). Effects of Moisture Intrusion on the Performance of a Cross-Laminated Timber (CLT) Angle Bracket Connection. MS Thesis. Oregon State University, Corvallis, OR. USA.
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Progress 03/01/19 to 02/29/20
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?At Oregon State University - This grant has provided opportunity for one gradaute student to attend and present at a major professional society convention. At Portland State university - This grant has provided an opportunity for one female undergraduatestudentand one graduate student to perform research under the supervision of the faculty member. Opportunities to attend and present research at local conferences such as the mass timber conference held in Portland will be encouraged. How have the results been disseminated to communities of interest?Some results have been presented at professional society meeting with academic leaders and industrial stakeholders in attendance. What do you plan to do during the next reporting period to accomplish the goals?In the next reporting period, we will conclude the moisture study on the CLT connections of four major species. Results will be analyzed and models to account for moisture effects will be produced.Moreover, we will have initial results from the biological study. We will also set up the full-scale moisture study involving a 10 feet tall wall test under different moisture conditions.Additionally, we plan to evaluate the developed algorithms on small- and large-scale mass timber panels and systems with known geometries and inclusions as well as simulated damage.
Impacts
What was accomplished under these goals?
The work was focussed on evaluating the effects of moisture and biological degradation on cross laminated timber connections. The experiment phase of the moisture study will conclude by the end of this reporting period. Data and results will be available to disseminate towards the end of the next reporting period. The biological study. however, is in its fledgling stages and will have initial results by the next reporting period. Asreported earlier, the species were expanded to include all the four major CLT producing species group (at no added cost to the project). The dataset generated will be one of the most comprehensive one for CLT durability. The main focus of our evlaution work to date has been to create algorithms in both MATLAB and Python that can read in raw data from our ultrasonic echo array (UEA) as well as the ground penetrating radar (GPR) instruments for data analysis and processing. This includes image reconstruction as well as fusion algorithms for the two measurements. Simultaneously, we have been working on creating a database of ultrasonic wave propagation characteristics that will be used as input to these algorithms. The database contains the following information for five different wood species: measured p-wave speed, mass density, incident angle with growth rings, and growth ring thickness.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Bora, S., Sinha, A. and Barbosa, A. (2019). Effect of moisture on CLT connection properties. Presentation in SWST International Convention, October, 2019, California.
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Progress 03/01/18 to 02/28/19
Outputs
Target Audience:
Nothing Reported
Changes/Problems:One major change was included, which doubled the scope of testing. The change was to add two more species type in the test matrix. This was done after much deliberation as with four species type evaluated, the scope of the project will now cover every major species in the world that CLT is made of. This was done at no additional cost to the project. What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?All the material will be here beginning of March 2019 and at that time fabrication of connections will commence. Five different moisture and biological exposures are being planned and they will run in parallel. Three exposures will be fully completed for all four species type and results willb e evaluated and reported. Progress is anticipated on the biological exposures as well as non-destructuve evaluation protocols established.
Impacts
What was accomplished under these goals?
First major step to evaluate the effect of species on durability was to procure cross laminated timber (CLT) manufactured from different species. After much deliberation and no-added cost to the project, four major specieswere decided upon for durability and connection durability evaluation. They cover the entire gamut of CLT production worldwide. THe species are - Douglas-fir, Southern Yellow Pine, European Spruce, and Spruce-Pine-Fir. Most of the material has been procured or ordered places. Hardware for connection has been manufactured. The project team's effort over the reporting period was directed towards recruiting relevant personnel for the project. Some challenges existed along the way. A graduate student and a post-doctoral scholar is on board and working towards setting up the experiment. Project kickoff meeting was conducted to discuss the details and regular update meetings are scheduled.
Publications
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