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Catalyzing Michigan Mass Timber Manufacture and Demand by Piloting Michigan-Sourced-and-Made Nail-Laminated Timber

https://research.thinkwood.com/en/permalink/catalogue3175
Year of Publication
2022
Topic
Market and Adoption
Material
NLT (Nail-Laminated Timber)
Organization
Michigan State University
Year of Publication
2022
Material
NLT (Nail-Laminated Timber)
Topic
Market and Adoption
Keywords
Local sourced
Local made
Research Status
In Progress
Notes
Forest Service/USDA Wood Innovations Grants Recipient Point of Contact: Sandra Lupien Location: East Lansing, Michigan
Summary
Over the past decade, interest in and demand for mass timber have been increasing steadily across North America for the materials’ ability to support healthy forests and rural economies while creating beautiful, innovative structures that both benefit the people who live, work, and learn in them and improve the carbon footprints of our built environments. The MassTimber@MSU program – supported in large part by funding from the Michigan Department of Natural Resources (DNR) and the Michigan Department of Agriculture and Rural Development (MDARD) – harnesses stakeholder engagement, outreach, communications, research, and education to advance mass timber construction and manufacture in Michigan and the surrounding region. Since the program’s launch two years ago, increased outreach leveraging new mass timber buildings in the region – the Michigan State University (MSU) STEM facility, the Intro project in Cleveland, and the Ascent Tower in Milwaukee – has intensified mass timber buzz in Michigan, where architecture, engineering, and construction (AEC) firms are reporting a steady stream of inquiries from developers studying mass timber for their projects. With this increased interest in mass timber construction come both concerns that demand could soon outstrip supply and significant interest in a secure Michigan-based supply of mass timber. Some Michigan forest products industry entities are investigating the potential of expanding to manufacture mass timber products like cross-laminated timber (CLT) and glue-laminated timber (glulam) but are hesitant to make the capital investment without formal evidence of regional demand for mass timber products generally as well as for such products made in Michigan from Michigan wood specifically. In addition, potential manufacturers need to better understand feedstock supply to determine the best location, scale, and mass timber product lines for Michigan mass timber. That means Michigan CLT and glulam won’t become a reality for at least 2-5 years. At the same time, State agencies are eager to quickly harness the forest health and economic development opportunities associated with using wood sourced from State, Federal, and private Michigan forestlands in Michigan-manufactured mass timber. Nail-laminated timber, a more species-agnostic form of mass timber panels that can be manufactured using nail guns on a project site or in a warehouse nearby, presents a unique “first-generation” mass timber opportunity for Michigan – one that can begin this year – that can help pave the way for larger scale operations in years to come. With this project we propose to demonstrate the use of Michigan-sourced-and-made NLT in two projects –Shophouse Park and the Great Lakes Boat Building School’s new building – in the Upper Peninsula. We will document the processes and outcomes of these projects and share theme – along with best practices – with key manufacturing, AEC industry, community development, and other stakeholders. We expect the project will increase market demand for mass timber, including Michigan-sourced-and-made mass timber, and catalyze Michigan-based manufacture of mass timber from wood sourced from Michigan and the surrounding Great Lakes. Surveying AEC and developer stakeholders at the start and end of the project will both inform our understanding of the project’s impact and provide evidence of demand to prospective manufacturers.
Less detail

Market Opportunities for Prefabricated Construction Using Mass Timber

https://research.thinkwood.com/en/permalink/catalogue2814
Topic
Market and Adoption
Material
CLT (Cross-Laminated Timber)
DLT (Dowel Laminated Timber)
Glulam (Glue-Laminated Timber)
Light Frame (Lumber+Panels)
NLT (Nail-Laminated Timber)
Application
Wood Building Systems
Organization
BlackBox Offsite Solutions
Material
CLT (Cross-Laminated Timber)
DLT (Dowel Laminated Timber)
Glulam (Glue-Laminated Timber)
Light Frame (Lumber+Panels)
NLT (Nail-Laminated Timber)
Application
Wood Building Systems
Topic
Market and Adoption
Keywords
Prefabrication
Mass Timber
Light-frame wood
Canada
Research Status
In Progress
Notes
Project contact is Craig Mitchell at Black Box Offsite Solutions (Canada)
Summary
The study assesses the current state of the prefabrication industry in Canada and identifies key challenges and potential market opportunities in the sector for the increased use of mass timber. This analysis of the current state of the industry examines all forms of prefabrication, with a focus on wood (light wood frame and mass timber) where possible. A more detailed analysis focuses on future mass timber market opportunities in Canada and globally, including prefabricated timber building elements (i.e. structural components, retrofit components, etc.) and building typologies. Recommendations will inform policy decisions and other efforts required to support the further development and adoption of prefabricated timber buildings in Canada.
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Development of a Clear Intumescent Coating for Mass Timber Construction: Fire Protection and Interior Application

https://research.thinkwood.com/en/permalink/catalogue2815
Topic
Fire
Application
Ceilings
Walls
Columns
Organization
National Research Council of Canada
Application
Ceilings
Walls
Columns
Topic
Fire
Keywords
Intumescent Coating
Mass Timber
Encapsulated Mass Timber Construction
Encapsulation
Fire Resistance Rating
Research Status
In Progress
Notes
Project contact is Rokib Hassan at the National Research Council of Canada
Summary
Phase two of a four-phased research project, with the overarching goal of developing transparent intumescent coating (TIC) for mass timber construction, which would be technology certified, IP protected and licensed out. The use of TIC would ensure that fire resistance rating requirements are met while reducing the need for encapsulation, resulting in increased overall aesthetics provided by timber. Phase two focuses on demonstrating a proof-of-concept on a small scale and optimizing the TIC formula and coating thickness based on the testing results. Small scale tests will be conducted to measure fire resistance, weatherability and fire toxicity.
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Mechanical Behavior of GFRP Dowel Connections to Cross Laminated Timber-CLT Panels

https://research.thinkwood.com/en/permalink/catalogue2957
Year of Publication
2022
Topic
Connections
Material
CLT (Cross-Laminated Timber)
Application
Floors
Walls
Author
Almeida, Amanda
Moura, Jorge
Organization
Maringá State University
Londrina State University
Editor
Knapic, Sofia
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Floors
Walls
Topic
Connections
Keywords
GFRP
Dowel-Type Connections
Panel-to-Panel
Design Methodology
Push-Out Tests
Research Status
Complete
Series
Forests
Summary
Sustainability issues are driving the civil construction industry to adopt and study more environmentally friendly technologies as an alternative to traditional masonry/concrete construction. In this context, plantation wood especially stands out as a constituent of the cross-laminated timber (CLT) system, laminated wood glued in perpendicular layers forming a solid-wood structural panel. CLT panels are commonly connected by screws or nails, and several authors have investigated the behavior of these connections. Glass-fiber-reinforced polymer (GFRP) dowels have been used to connect wooden structures, and have presented excellent performance results; however, they have not yet been tested in CLT. Therefore, the objective of this study is to analyze the glass-fiber-reinforced polymer (GFRP)-doweled connections between CLT panels. The specimens were submitted to monotonic shear loading, following the test protocol described in EN 26891-1991. Two configurations of adjacent five-layer panels were tested: flat-butt connections with 45° dowels (x, y, and z axes), and half-lap connections with 90° dowels. The results were evaluated according to the mechanical connection properties of strength, stiffness, and ductility ratio. The results showed higher stiffness for butt-end connections. In terms of strength, the half-lap connections were stronger than the butt-end connections.
Online Access
Free
Resource Link
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Contemporary and Novel Hold-Down Solutions for Mass Timber Shear Walls

https://research.thinkwood.com/en/permalink/catalogue2941
Year of Publication
2022
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Author
Tannert, Thomas
Loss, Cristiano
Organization
University of Northern British Columbia
University of British Columbia
Editor
Tullini, Nerio
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Topic
Mechanical Properties
Keywords
Self-Tapping Screws
Internal-Perforated Steel Plates
Hyperelastic Bearing Pads
Proprietary Connections
Research Status
Complete
Series
Buildings
Summary
‘Mass timber’ engineered wood products in general, and cross-laminated timber in particular, are gaining popularity in residential, non-residential, as well as mid- and high-rise structural applications. These applications include lateral force-resisting systems, such as shear walls. The prospect of building larger and taller timber buildings creates structural design challenges; one of them being that lateral forces from wind and earthquakes are larger and create higher demands on the ‘hold-downs’ in shear wall buildings. These demands are multiple: strength to resist loads, lateral stiffness to minimize deflections and damage, as well as deformation compatibility to accommodate the desired system rocking behaviour during an earthquake. In this paper, contemporary and novel hold-down solutions for mass timber shear walls are presented and discussed, including recent research on internal-perforated steel plates fastened with self-drilling dowels, hyperelastic rubber pads with steel rods, and high-strength hold-downs with self-tapping screws.
Online Access
Free
Resource Link
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A State of the Art of the Overall Energy Efficiency of Wood Buildings—An Overview and Future Possibilities

https://research.thinkwood.com/en/permalink/catalogue2943
Year of Publication
2021
Topic
Energy Performance
Application
Wood Building Systems
Author
Cabral, Matheus
Blanchet, Pierre
Organization
Université Laval
Editor
Koenders, Eddie
Publisher
MDPI
Year of Publication
2021
Format
Journal Article
Application
Wood Building Systems
Topic
Energy Performance
Keywords
Construction
Energy Efficiency
Embodied Energy
Mass Timber
Phase-Changing Materials
Post-and-Beam
Wood Composites
Wood-Frame
Research Status
Complete
Series
Materials
Summary
The main goal of this study was to review current studies on the state of the art of wood constructions with a particular focus on energy efficiency, which could serve as a valuable source of information for both industry and scholars. This review begins with an overview of the role of materials in wood buildings to improve energy performance, covering structural and insulation materials that have already been successfully used in the market for general applications over the years. Subsequently, studies of different wood building systems (i.e., wood-frame, post-and-beam, mass timber and hybrid constructions) and energy efficiency are discussed. This is followed by a brief introduction to strategies to increase the energy efficiency of constructions. Finally, remarks and future research opportunities for wood buildings are highlighted. Some general recommendations for developing more energy-efficient wood buildings are identified in the literature and discussed. There is a lack of emerging construction concepts for wood-frame and post-and-beam buildings and a lack of design codes and specifications for mass timber and hybrid buildings. From the perspective of the potential environmental benefits of these systems as a whole, and their effects on energy efficiency and embodied energy in constructions, there are barriers that need to be considered in the future.
Online Access
Free
Resource Link
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Finite Element Modeling on Shear Performance of Grouted Stud Connectors for Steel–Timber Composite Beams

https://research.thinkwood.com/en/permalink/catalogue2944
Year of Publication
2022
Topic
Mechanical Properties
Material
Steel-Timber Composite
Application
Beams
Author
Zhang, Henan
Ling, Zhibin
Organization
Suzhou University of Science and Technology
Editor
Lopes, Sérgio
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Material
Steel-Timber Composite
Application
Beams
Topic
Mechanical Properties
Keywords
Shear Connection
Finite Element Modeling
Grouted Stud Connections
Research Status
Complete
Series
Materials
Summary
Steel–timber composite (STC) systems are considered as an environmentally friendly alternative to steel–concrete composite (SCC) structures due to its advantages including high strength-to-weight ratio, lower carbon footprint, and fully dry construction. Bolts and screws are the most commonly used connectors in STC system; however, they probably make great demands on the accuracy of construction because of the predrilling in both the timber slabs and steel girder fangles. To address this issue, the STC connections with grouted stud connectors (GSC) were proposed in this paper. In addition, stud connectors can also provide outstanding stiffness and load-bearing capacity. The mechanical characteristic of the GSC connections was exploratorily investigated by finite element (FE) modeling. The designed parameters for the FE models include stud diameter, stud strength, angle of outer layer of cross-laminated timber (CLT) panel, tapered groove configurations, and thickness of CLT panel. The numerical results indicated that the shear capacity and stiffness of the GSC connections were mainly influenced by stud diameter, stud strength, angle of outer layer of CLT panel, and the angle of the tapered grooves. Moreover, the FE simulated shear capacity of the GSC connections were compared with the results predicted by the available calculation formulas in design codes and literatures. Finally, the group effect of the GSC connections with multiple rows of studs was discussed based on the numerical results and parametric analyses. An effective row number of studs was proposed to characterize the group effect of the GSC connections.
Online Access
Free
Resource Link
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Rolling Shear Properties of Cross-Laminated Timber Made from Australian Plantation Eucalyptus nitens under Planar Shear Test

https://research.thinkwood.com/en/permalink/catalogue2945
Year of Publication
2022
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Author
Ettelaei, Azin
Taoum, Assaad
Shanks, Jon
Nolan, Gregory
Organization
University of Tasmania
Editor
Oliveira, Diego
Publisher
MDPI
Year of Publication
2022
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Wood Building Systems
Topic
Mechanical Properties
Keywords
Rolling Shear
Hardwood Plantation
Planar Shear Tests
Structural Properties
Research Status
Complete
Series
Forests
Summary
With the increasing availability of fast-growing Eucalyptus plantation logs in Australia in recent years, the timber manufacturing sector has become interested in discovering the opportunities of producing value-added timber products from this resource. Cross-laminated timber (CLT) could be a potential sustainable product recovered from this resource and supply material for commercial buildings. Shear of the inner cross-laminates, known as rolling shear, is one of the governing factors in serviceability and limit state design for this product under out-of-plane loading. This study evaluated the rolling shear (RS) properties of CLT with heterogonous layup configurations using different structural grade Eucalyptus nitens (E. nitens) timber under the planar shear test. Based on the results, Gr and tr values were shown to be significantly correlated with the density of the CLT panel. There was also a positive correlation between the RS modulus and MOR of the CLT panel. The specimens with high MOE in the top and bottom layers indicated the highest tr and Fmax values. This indicated that using high-grade boards in the top and bottom lamellae plays an important role in increasing the RS strength, whereas using them in the cross-layer has a positive contribution in increasing shear modulus. The maximum observed RS strength and modulus ranged from 2.8–3.4 MPa and 54.3–67.9 MPa, respectively, exceeding the RS characteristic values of the resource. The results obtained in this study were comparable to those recommended in European standards for softwood CLT, demonstrating the potential use for eucalypt timber boards in CLT production. This paper provides an important insight into supporting the potential engineering applications of CLT panel products fabricated with eucalypt plantation.
Online Access
Free
Resource Link
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Load-carrying capacity of self-tapping lag screws for glulam-lightweight concrete composite beams

https://research.thinkwood.com/en/permalink/catalogue3392
Year of Publication
2019
Topic
Mechanical Properties
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Author
Du, Hao
Hu, Xiamin
Jiang, Yuchen
Wei, Chenyu
Hong, Wan
Organization
Nanjing Tech University
Year of Publication
2019
Format
Journal Article
Material
Glulam (Glue-Laminated Timber)
Application
Beams
Topic
Mechanical Properties
Keywords
Push-out Test
Load-Carrying Capacity
Analytical Model
Research Status
Complete
Series
BioResources
Summary
When a lag screw with a large diameter is used as the shear connector in timer-concrete composite beams, the procedure of pre-drilling is required during the construction process. In this paper, a new type of lag screw was proposed to omit the pre-drilling step. To investigate the shear behavior of the self-tapping lag screws for glulam-lightweight concrete composite beams, a total of 18 push-out tests were conducted. Based on the push-out test results, the influences of concrete type, screw diameter, and penetration length of screw into timber on the load-carrying capacity were analyzed in detail. The push-out test results showed that the concrete type had no remarkable effect on the load-carrying capacity. The load-carrying capacity was improved with increased screw diameter and penetration length. In addition, an analytical model for load-carrying capacity of lag screw connectors was proposed based on the push-out test results. By comparisons, it was found that the timber-timber and steel-timber models proposed in Eurocode 5 made very conservative predictions on the load-carrying capacity of lag screws. The results of the analytical method presented in this paper showed a better agreement with the experimental results.
Online Access
Free
Resource Link
Less detail

Study on energy conservation and carbon emission reduction design of timber structure building

https://research.thinkwood.com/en/permalink/catalogue3393
Year of Publication
2019
Topic
Environmental Impact
Author
Yue, Miao
Li, Wenxian
Cheng, Xinling
Chen, Yujie
Xu, Liu
Shi, Yanshuai
Organization
Xiaoshan Higher Education Park
Year of Publication
2019
Format
Journal Article
Topic
Environmental Impact
Keywords
Life Cycle Analysis
Series
The Journal of Engineering
Summary
Replacing traditional building materials with renewable and sustainable materials such as timber can control environmental pollution such as energy consumption and carbon emission in the whole life cycle of a building, which is conducive to energy conservation and environmental protection. How to design timber structure building better is the focus of this study. This study takes timber structure building as the research object, evaluates the building energy consumption and CO2 emission with the whole life cycle concept. The comparative ecological advantages of timber structure building are obtained by comparing and analysing the brick-concrete structure building with equivalent thermal performance. Then by analysing the different spaces of timber structure building design, the design suggestions of energy saving and carbon reduction such as reducing the platform area appropriately and increasing the number of building floors are proposed when designing timber structure buildings.
Online Access
Free
Resource Link
Less detail

Fire Safety of Mass timber Buildings with CLT in USA

https://research.thinkwood.com/en/permalink/catalogue3325
Year of Publication
2018
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Author
Barber, David
Organization
ARUP
Year of Publication
2018
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Mass Timber
Cross Laminated Timber
Fire Safety
Fire Testing
Performance Based Design
Research Status
Complete
Series
Wood and Fiber Science
Summary
Multistory buildings using mass timber and cross-laminated timber (CLT) as the primary structural elements are being planned and constructed globally, with interest starting to gather momentum in the United States. Model building codes in the United States limit timber construction to a building height of 85 ft (25.9 m) because of concerns over fire safety and structural performance. Up to 85 ft, the mass timber can be exposed. Architects and developers in the United States are pushing boundaries, requesting mass timber structures are constructed as high-rises and that load-bearing mass timber such as CLT be exposed and not fully protected. This provides an opportunity for the application of recent fire research and fire testing on exposed CLT to be applied, and existing methods of analyzing the impact of fire on engineered timber structures to be developed further. Fire testing has shown that exposing large areas of CLT significantly impacts the heat release rate and fire duration. This article provides an overview of the code requirements for timber construction in the United States, provides methods for building approval for a high-rise timber structure, and summarizes recent CLT compartment fire testing that is informing the fire engineering process. Methods for solutions are also discussed.
Online Access
Free
Resource Link
Less detail

Durability of Mass Timber Structures: A Review of the Biological Risks

https://research.thinkwood.com/en/permalink/catalogue3326
Year of Publication
2018
Topic
Serviceability
Material
CLT (Cross-Laminated Timber)
Author
Wang, J. Y.
Stirling, R.
Morris, Paul I.
Taylor, A.
Lloyd, J.
Kirker, G.
Lebow, S.
Mankowski, M.
Barnes, H. M.
Morrell, J. J.
Organization
FPInnovations
University of Tennessee
Nisus Corporation
Forest Products Laboratory
Mississippi State University
Oregon State University
Publisher
PKP Publishing Services Network
Year of Publication
2018
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Serviceability
Keywords
Mass Timber
Durability
Wood Protection
Research Status
Complete
Series
Wood and Fiber Science
Summary
Mass timber structures have the potential to change wooden construction on a global scale. Numerous mass timber high-rise buildings are in planning, under development or already built and their performance will alter how architects and engineers view wood as a material. To date, the discussion of material durability and biodegradation in these structures has been limited. While all materials can be degraded by wetting, the potential for biodegradation of wood in a mass timber building requires special consideration. Identifying and eliminating the conditions that might lead to this degradation will be critical for ensuring proper performance of wood in these structures. This article reviews and contrasts potential sources of biodegradation that exist for traditional wood construction with those in mass timber construction and identifies methods for limiting the degradation risk. Finally, future research needs are outlined.
Online Access
Free
Resource Link
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Fire Safety of CLT Buildings in New Zealand and Australia

https://research.thinkwood.com/en/permalink/catalogue3327
Year of Publication
2018
Topic
Fire
Material
CLT (Cross-Laminated Timber)
Author
Buchanan, Andrew
Dunn, Andrew
O'Neill, James
Pau, Dennis
Organization
PTL Structural Timber Consultants
Timber Development Association (NSW)
Holmes Fire
University of Canterbury
Publisher
PKP Publishing Services Network
Year of Publication
2018
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Topic
Fire
Keywords
Regulations
Codes
Research Status
Complete
Series
Wood and Fiber Science
Summary
This article summarizes the design procedures for ensuring fire safety in cross laminated timber (CLT) buildings in Australia and New Zealand, with reference to the Building Codes in both countries. New Zealand and Australia are located close together geographically and have similarities in some areas of building control, but prescriptive code requirements are often very different. There is a small but growing local CLT industry, but CLT materials for large projects are imported from Europe.
Online Access
Free
Resource Link
Less detail

Costing Analysis for Common Mass-timber Archetypes

https://research.thinkwood.com/en/permalink/catalogue2812
Topic
Cost
Design and Systems
Energy Performance
Material
CLT (Cross-Laminated Timber)
DLT (Dowel Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Hybrid Building Systems
Building Envelope
Organization
Morrison Hershield
Material
CLT (Cross-Laminated Timber)
DLT (Dowel Laminated Timber)
Glulam (Glue-Laminated Timber)
Application
Wood Building Systems
Hybrid Building Systems
Building Envelope
Topic
Cost
Design and Systems
Energy Performance
Keywords
Parametric Design
Cost
Mass Timber
Building Code
BC Energy Step Code
National Energy Code of Canada for Buildings
Research Status
In Progress
Notes
Project contact is Eric Wood at Morrison Hershfield (Canada)
Summary
The project develops building archetypes, cost data and energy modelling to allow users to cost out mass timber buildings from basic, code-compliant buildings to high-performing, energy-efficient, low-emitting buildings. It will help quantity surveyors, designers, and other decisionmakers undertake business-case development by clarifying cost variables associated with mass-timber construction.
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Mass Timber Economics of 7-12 Storey Residential Rental Buildings

https://research.thinkwood.com/en/permalink/catalogue2813
Topic
Cost
Design and Systems
Material
CLT (Cross-Laminated Timber)
DLT (Dowel Laminated Timber)
Glulam (Glue-Laminated Timber)
NLT (Nail-Laminated Timber)
Application
Wood Building Systems
Organization
Morrison Hershield
BC Housing
Material
CLT (Cross-Laminated Timber)
DLT (Dowel Laminated Timber)
Glulam (Glue-Laminated Timber)
NLT (Nail-Laminated Timber)
Application
Wood Building Systems
Topic
Cost
Design and Systems
Keywords
Cost Effective
Cost-Competitive
ROI
Building Code
Affordable Housing
Mass Timber
Research Status
In Progress
Notes
Project contact is Eric Wood at Morrison Hershfield (Canada)
Summary
The study assesses the potential of mass timber multi-unit residential construction as it compares to traditional methods including concrete and steel in terms of cost competitiveness, cost effectiveness, financial value and ROI. The analysis will include potential limitations of existing building codes, how the codes support or constrain the use of mass timber, including impacts to affordability, and whether further industry and government support of tall wood construction is needed to integrate it into Canada’s housing supply. To inform the analysis, the study produces base case archetypes for concrete and steel structures, and then create a series of comparative archetypes mass timber structures and hybrid structures in the range of 7-12 storeys.
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Sustainability Design Considerations for Timber-Concrete Composite Floor Systems

https://research.thinkwood.com/en/permalink/catalogue3090
Year of Publication
2021
Topic
Design and Systems
Material
Timber-Concrete Composite
Application
Floors
Author
Mirdad, Md Abdul Hamid
Daneshvar, Hossein
Joyce, Thomas
Chui, Ying Hei
Organization
University of Alberta
Publisher
Hindawi
Year of Publication
2021
Format
Journal Article
Material
Timber-Concrete Composite
Application
Floors
Topic
Design and Systems
Keywords
Span Table
Embodied Carbon
Serviceability Limite State
Ultimate Limite State
Research Status
Complete
Series
Advances in Civil Engineering
Summary
Over the last few decades, there has been growing interest in the use of low-carbon materials to reduce the environmental impacts of the construction industry. The advent of mass timber panels (MTP), such as cross laminated timber (CLT), has allowed structural engineers to specify a low-carbon material for a variety of floor design considerations. However, serviceability issues such as vibration and deflection are limiting the construction of longer span timber-only floor systems and have encouraged the development of timber-concrete composite (TCC) systems. The use of concrete would negatively impact on the carbon footprint of the TCC floor system and should be minimized. The purpose of this study was to study the impact on embodied carbon in the TCC system, when the ratio of timber and concrete was varied for specific floor spans. Two MTP products were considered, CLT and glued laminated timber (GLT). The floors were designed to satisfy structural, acoustic, and vibration criteria, and the results were presented in the form of span tables. It was found that using thicker MTP instead of adding concrete thickness to meet a specific span requirement can lead to lower embodied carbon values. Increasing concrete thickness for long-span floor systems led to a reduction in allowable floor span due to the vibration criterion being the controlling design parameter. Increasing timber thickness also resulted in higher strength and stiffness to weight ratios, which would contribute toward reducing the size of lateral load resisting systems and foundations, resulting in further reductions in the embodied carbon of the entire structure.
Online Access
Free
Resource Link
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A Review of the Methods for Predicting the Effective In-Plane Shear Modulus of Cross-Laminated Timber (CLT)

https://research.thinkwood.com/en/permalink/catalogue3091
Year of Publication
2021
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Author
Khan, Mehsam Tanzim
Chui, Ying Hei
Huang Dongsheng
Organization
University of Alberta
Nanjing Forestry University
Publisher
Hindawi
Year of Publication
2021
Format
Journal Article
Material
CLT (Cross-Laminated Timber)
Application
Shear Walls
Topic
Mechanical Properties
Keywords
In-Plane Shear
Effective Shear Modulus
Research Status
Complete
Series
Advances in Civil Engineering
Summary
Cross-laminated timber (CLT) is a type of engineered wood product that offers both high in-plane and out-of-plane load-bearing capacity. It is slowly becoming an alternative material for building high-rise structures. However, there is no current standard or regulation for determining the shear modulus of CLT under in-plane loading condition, which is a very important property for its use as structural members. Few methods have been proposed over the last decade to determine the in-plane shear modulus of CLT. Almost all of the methods proposed until now have their strengths and weaknesses. In this paper, some of the prominent methods for determining the in-plane shear modulus of CLT are described and analysed. The descriptions along with the critical discussions will facilitate a better understanding and might pave the way to further enhancements of the method(s) to determine the in-plane shear modulus of CLT.
Online Access
Free
Resource Link
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Wood Vault: remove atmospheric CO2 with trees, store wood for carbon sequestration for now and as biomass, bioenergy and carbon reserve for the future

https://research.thinkwood.com/en/permalink/catalogue3086
Year of Publication
2022
Topic
Environmental Impact
Author
Zeng, Ning
Hausmann, Henry
Organization
University of Maryland
Publisher
Springer
Year of Publication
2022
Format
Journal Article
Topic
Environmental Impact
Keywords
Wood Harvesting and Storage
Wood Vault
Research Status
Complete
Series
Carbon Balance and Management
Summary
Background Wood harvesting and storage (WHS) is a hybrid Nature-Engineering combination method to combat climate change by harvesting wood sustainably and storing it semi-permanently for carbon sequestration. To date, the technology has only been purposefully tested in small-scale demonstration projects. This study aims to develop a concrete way to carry out WHS at large-scale. Results We describe a method of constructing a wood storage facility, named Wood Vault, that can bury woody biomass on a mega-tonne scale in specially engineered enclosures to ensure anaerobic environments, thus preventing wood decay. The buried wood enters a quasi-geological reservoir that is expected to stay intact semi-permanently. Storing wood in many environments is possible, leading to seven versions of Wood Vault: (1) Burial Mound (Tumulus or Barrow), (2) Underground (Pit, Quarry, or Mine), (3) Super Vault, (4) Shelter, (5) AquaOpen or AquaVault with wood submerged under water, (6) DesertOpen or DesertVault in dry regions, (7) FreezeVault in cold regions such as Antarctica. Smaller sizes are also possible, named Baby Vault. A prototype Wood Vault Unit (WVU) occupies 1 hectare (ha, 100 m by 100 m) of surface land, 20 m tall, stores up to 100,000 m3 of wood, sequestering 0.1 MtCO2. A 1 MtCO2 y-1 sequestration rate can be achieved by collecting currently unused wood residuals (WR) on an area of 25,000 km2, the size of 10 typical counties in the eastern US, corresponding to an average transportation distance of less than 100 km. After 30 years of operation, such a Wood Vault facility would have sequestered 30 MtCO2, stored in 300 WVUs, occupying a land surface of 300 ha. The cost is estimated at $10–50/tCO2 with a mid-point price of $30/tCO2. To sequester 1 GtCO2 y-1, wood can be sourced from currently unexploited wood residuals on an area of 9 Mkm2 forested land (9 million square kilometers, size of the US), corresponding to a low areal harvesting intensity of 1.1 tCO2 ha-1 y-1. Alternatively, giga-tonne scale carbon removal can be achieved by harvesting wood at a medium harvesting intensity of 4 tCO2 ha-1 y-1 on 3 Mkm2 of forest (equivalent to increasing current world wood harvest rate by 25%), or harvest on 0.8 Mkm2 forest restored from past Amazon deforestation at high harvest intensity, or many combinations of these and other possibilities. It takes 1000 facilities as discussed above to store 1 GtCO2 y-1, compared to more than 6000 landfills currently in operation in the US. After full closure of a Wood Vault, the land can be utilized for recreation, agriculture, solar farm, or agrivoltaics. A more distributed small operator model (Baby Vault) has somewhat different operation and economic constraints. A 10 giga-tonne sequestration rate siphons off only 5% of total terrestrial net primary production, thus possible with WHS, but extreme caution needs to be taken to ensure sustainable wood sourcing. Conclusions Our technical and economic analysis shows that Wood Vault can be a powerful tool to sequester carbon reliably, using a variety of wood sources. Most pieces of the technology already exist, but they need to be put together efficiently in practice. Some uncertainties need to be addressed, including how durability of buried wood depends on detailed storage methods and burial environment, but the science and technology are known well enough to believe the practicality of the method. The high durability, verifiability and low-cost makes it already an attractive option in the current global carbon market. Woody biomass stored in Wood Vaults is not only a carbon sink to combat current climate crisis, but also a valuable resource for the future that can be used as biomass/bioenergy and carbon supply. The quantity of this wood utilization can be controlled carefully to maintain a desired amount of CO2 in the atmosphere to keep the Earth’s climate from diving into the next ice age, acting as a climate thermostat. The CO2 drawdown time is on the order of 100 years while the ramp-up time is a decade. A sense of urgency is warranted because the CO2 removal rate is limited by biosphere productivity, thus delayed action means a loss of opportunity. In conclusion, WHS provides a tool for managing our Earth system, which will likely remain forever in the Anthropocene.
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Inward- versus outward-focused bioeconomy strategies for British Columbia’s forest products industry: a harvested wood products carbon storage and emission perspective

https://research.thinkwood.com/en/permalink/catalogue3087
Year of Publication
2021
Topic
Environmental Impact
Author
Xie, Sheng H.
Kurz, Werner A.
McFarlane, Paul N.
Organization
Pacifc Institute for Climate Solutions
Publisher
Springer
Year of Publication
2021
Format
Journal Article
Topic
Environmental Impact
Keywords
Climate Change Mitigation
Emission Reduction
Carbon Dynamics Modeling
Harvested Wood Products
Bioeconomy
Mass Timber Construction
Biofuel
Pulp and Paper
Wood Pellets
Research Status
Complete
Series
Carbon Balance and Management
Summary
Background British Columbia’s (BC) extensive forest resources provide climate change mitigation opportunities that are available to few other jurisdictions. However, as a consequence of the Mountain Pine Beetle outbreak and large-scale wildfires, BC is anticipating reduced roundwood harvest for the next decades. Progress towards more climatically efficient utilization of forest resources is needed. This research quantitatively compared the greenhouse gas emission consequences of nine harvested wood products trade and consumption strategies. Inward-focused strategies use wood products within Canada to achieve emission reduction objectives, while outward-focused strategies encourage exports of wood products. Results In the business-as-usual baseline scenario, average emissions arising from BC-originated harvested wood products between 2016 and 2050 were 40 MtCO2e yr-1. The estimated theoretical boundaries were 11 MtCO2e yr-1 and 54 MtCO2e yr-1, under the scenarios of using all harvests for either construction purposes or biofuel production, respectively. Due to the constrained domestic market size, inward-focused scenarios that were based on population and market capacity achieved 0.3–10% emission reductions compared to the baseline. The international markets were larger, however the emissions varied substantially between 68% reduction and 25% increase depending on wood products’ end uses. Conclusions Future bioeconomy strategies can have a substantial impact on emissions. This analysis revealed that from a carbon storage and emission perspective, it was better to consume BC’s harvests within Canada and only export those products that would be used for long-lived construction applications, provided that construction market access beyond the US was available. However, restricting export of wood products destined for short-lived uses such as pulp and wood pellets would have significant economic and social impacts. On the other hand, inward-focused strategies had a small but politically and environmentally meaningful contribution to BC’s climate action plan. This study also revealed the conflicts between a demand-driven bioeconomy and targeted environmental outcomes. A hierarchical incentive system that could co-exist with other market drivers may help achieve emission reduction goals, but this would require a better quantitative understanding of wood products’ substitution effects. While the analyses were conducted for BC, other regions that are net exporters of wood products may face similar issues.
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Free
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Cross-Laminated Timber—North American CLT vs. Imported Product

https://research.thinkwood.com/en/permalink/catalogue3088
Year of Publication
2020
Topic
General Information
Material
CLT (Cross-Laminated Timber)
Organization
APA
Year of Publication
2020
Format
Document
Material
CLT (Cross-Laminated Timber)
Topic
General Information
Keywords
Design Property Compatibility
Adhesive Heat Durability
Moisture Durability
Fire Performance
Research Status
Complete
Summary
Cross-laminated timber (CLT) manufactured in North America must meet stringent product standards and be certified to the ANSI/APA PRG 320 Standard for Performance-Rated Cross-Laminated Timber. This publication from APA - The Engineered Wood Association explains the key characteristics that are evaluated in certification process. When comparing North Amarican CLT to products manufactured elsewhere, it is important to recognize that products manufactured outside of North Amarica may not meet the performance expections defined in the ANSI standard.
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Free
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