Evaluating Volatile Organic Compound Emissions from Cross-Laminated Timber Bonded with a Soy-Based Adhesive
https://www.mdpi.com/2075-5309/10/11/191... [Bonding/Adhesives] [Journal Article] 2020
Yauk, M., Stenson, J., Donor, M., & Van Den Wymelenberg, K.
Volatile organic compound (VOC) emissions from indoor sources are large determinants of the indoor air quality (IAQ) and occupant health. Cross-laminated timber (CLT) is a panelized engineered wood product often left exposed as an interior surface finish. As a certified structural building product, CLT is currently exempt from meeting VOC emission limits for composite wood products and confirming emissions through California Department of Public Health (CDPH) Standard Method testing. In this stu...

A Visual Assessment of Cross-laminated Timber Structures in Austria
https://biobus.swst.org/bpbj/index.php/bpbj/articl... [Markets] [Journal Article] 2020
Henry Quesada-Pineda, Robert Smith, Guenter Berger, Joseph Loferski
Cross-laminated timber (CLT) construction systems have been used commercially for over 20 years, mainly in Western Europe and North America. However, there has not been a report on the current status of CLT buildings. Deterioration of wooden buildings could result from a variety of causes and the life of the structures could be extended if periodic inspections were conducted. This research introduces a visual inspection methodology for assessing deterioration of CLT structures. The inspection me...

Environmental Product Declaration CLT
https://www.storaenso.com/-/media/documents/downlo... [Environmental Performance] [Report] 2020
Stora Enso
CLT is a solid wood construction product consisting of several (3, 5, 7, or 8) bonded single-layer panels arranged at right angles to each other. The layers are bonded with carefully selected adhesives that are suitable for the respective purpose. CLT products are long-lasting and safe to use and recyclable. They are continuously tested to ensure that they meet the strictest requirements in terms of ambient air emissions. CLT also offers virtually boundless possibilities in terms of construction...

Three-dimensional stress analysis and design of cross-laminated timber panels using full-layerwise-theory-based finite element method
https://www.sciencedirect.com/science/article/abs/... [Mechanical Performance] [Journal Article] 2020
Miroslav Marjanović, Nemanja Marković, Emilija Damnjanović, Radovan Cvetković
Cross-laminated timber (CLT) panels have an increasing market share and extensive application in civil engineering, as full size walls or light floor structures. Due to their low environmental impact, excellent thermal characteristics and high mechanical performance, they are being extensively applied instead of conventional mineral-based building materials. Thick and orthogonal structure of CLT provides the considerable stiffness with the low weight and makes such panels particularly suitable i...

Rolling shear modulus and strength of cross-laminated timber treated with micronized copper azole type C (MCA-C)
https://www.sciencedirect.com/science/article/abs/... [Moisture/Durability] [Journal Article] 2020
Hyungsuk Lim, SachinTripathi, Minghao Li
The effect of micronized copper azole type C (MCA-C) treatment on rolling shear (RS) strength and RS modulus of cross-laminated timber (CLT) was evaluated. The CLT test specimens were either constructed with untreated 2 × 6 (38 mm × 140 mm) No. 2. southern yellow pine (the United States grown) laminations or MCA-C treated laminations. The shear-free modulus of elasticity (Esf) and longitudinal-radial shear modulus (GLR) of the laminations were non-destructively measured prior to CLT manufacturin...

Shear Properties of Symmetric Angle-Ply Cross-Laminated Timber Panels
https://ascelibrary.org/doi/full/10.1061/%28ASCE%2... [Mechanical Performance] [Journal Article] 2020
A. Bahmanzad, P. L. Clouston, S. R. Arwade, A. C. Schreyer
The development of cross-laminated timber (CLT) technology has revolutionized the construction industry, enabling wood into new markets and exciting large-scale applications. The traditional 90° layup of CLT, however, is rudimentary compared to most laminated composite materials (e.g., for the aerospace industry or sports equipment) and could be viewed as just the starting point for the next generation of mass timber panels. This study examines the effect of varying fiber orientation of the mid-...

Elastic Response of Cross-Laminated Timber Panels using Finite Element and Analytical Techniques
https://cdnsciencepub.com/doi/abs/10.1139/cjce-202... [Mechanical Performance] [Journal Article] 2020
Asad S. Albostami, Zhangjian Wu, Lee Cunningham
Cross-Laminated Timber (CLT) is an engineered timber composite that is finding increasing structural application in construction today. Analysis of the structural behavior of CLT can be carried out by various analytical and numerical methods. Due to the complex behavior of CLT, use of numerical modelling such as the Finite Element Method (FEM) offers a convenient approach to analysis. In this paper, simulation of the elastic behavior of 1-way and 2-way spanning CLT panels using the FEM program A...

Small Scale Test to Measure the Strength of Adhesives at Elevated Temperatures for Use in Evaluating Adhesives for Cross Laminated Timber (CLT)
https://idp.springer.com/authorize?response_type=c... [Bonding/Adhesives] [Journal Article] 2020
Samuel L. Zelinka, Byrne Miyamoto, Nathan J. Bechle, Douglas Rammer
Cross laminated timber (CLT) is becoming widely available in North America. The product standard for North American CLT, PRG-320, has strict requirements on adhesive performance under fire scenarios. To become an adhesive certified under PRG-320, a full sized CLT compartment must be built and tested without a second flashover occurring caused by delamination. Currently, only three adhesive formulations are PRG-320 certified. This large scale test is expensive to run and only yields “pass-fail” r...

Bending performances and rolling shear strength of nail-cross-laminated timber
https://www.tandfonline.com/doi/abs/10.1080/174802... [Alternative/Hybrid Configurations] [Journal Article] 2020
Serveh Hosseinzadeh, Behbood Mohebby, Majid Elyasi
This current research work was aimed to develop an innovative panel by combining the nail-laminated timber (NLT) and cross-laminated timber (CLT) into a single product named nail-cross-laminated timber (NCLT) to take advantage of both structural panel products in a single product as a structural member. To investigate the mechanical properties of the NCLT, its bending performance and rolling shear were examined and compared to those of conventional CLT and NLT floor panels. The NCLT and the CLT ...

Analysis of the Characteristics of External Walls of Wooden Prefab Cross Laminated Timber
https://www.mdpi.com/1996-1073/13/22/5974... [Design/Architectural aspects] [Journal Article] 2020
Švajlenka, J., Kozlovská, M., Badida, M., Moravec, M., Dzuro, T., & Vranay, F.
A balanced combination of heat flows creates suitable conditions for thermal comfort—a factor contributing to the quality of the internal environment of buildings. The presented analysis of selected thermal-technical parameters is up-to-date and suitable for verifying the parameters of building constructions. The research also applied a methodology for examining the acoustic parameters of structural parts of buildings in laboratory conditions. In this research, selected variant solutions of peri...

Predicting failure of notched cross-laminated timber plates including the effect of environmental stresses
https://www.tandfonline.com/doi/abs/10.1080/174802... [Mechanical Performance] [Journal Article] 2020
John Nairn
This paper derives analytical predictions for notched cross-laminated timber (CLT) plate delamination using fracture mechanics for crack propagation from the notch root. The analysis accounts for both CLT heterogeneity and residual stresses caused by seasonal variations in temperature and humidity. The accuracy of predictions coupled with shear corrections, was confirmed by comparison to finite element analysis. The fracture mechanics approach was validated as appropriate by comparison to recent...

Withdrawal Behaviour of Self-tapping Screws in New Zealand Cross-Laminated Timber
https://ir.canterbury.ac.nz/handle/10092/100775... [Connectors] [Journal Article] 2020
Brown J, Li M, Karalus B, Stanton S
Self-tapping Screws (STS) are commonly used in cross-laminated timber (CLT) construction. However, design provisions with STS and CLT are currently not covered by NZS 3603:1993 or AS 1720.1:2010. Manufactured by hardened steel, STS have high withdrawal strength and provide an efficient connection type. Previous research and analytical design equations for STS connections were focused on European softwood species which often have lower densities than New Zealand grown Radiata Pine and Douglas-fir...

Industry driven innovation in healthy housing delivery: the case for Cross Laminated Timber
https://www.tandfonline.com/doi/full/10.1080/23748... [Markets] [Journal Article] 2020
Katharine Martindale
The delivery of housing has long been an issue of concern for academics, policymakers and built environment professionals. In recent years, Cross Laminated Timber has attracted significant interest among architects and their clients for its environmental and health benefits, as well as reduced build times. The Government’s Future of Cities Foresight briefing note identifies timber as a key material for the city and its role in small, domestic scale structural applications. This paper uses interv...

Development of cross-laminated timber (CLT) products from stress graded Canadian hem-fir
http://www.woodresearch.sk/wr/202002/14.pdf... [Raw Materials] [Journal Article] 2020
Wei, P., Wang, B. J., Li, Z., & Ju, R.
To explore the feasibility of hem-fir for CLT products, this work addressed the exploratory and pilot plant studies of hem-fir cross-laminated timber (CLT) products through mechanical tests. The hem-fir lumber was procured and then stress-graded based on dynamic modulus of elasticity (MOE). The resulted 5-ply prototype CLT products were then tested non-destructively and 3-ply pilot plant hem-fir CLT was tested destructively. The results showed that bending performance of hem-fir CLT panel can be...

Seeing the Forest and the Trees: Environmental Impacts of Cross-Laminated Timber
https://www.tandfonline.com/doi/full/10.1080/24751... [Environmental Performance] [Journal Article] 2020
Alison Kwok,Hannah Zalusky,Maria Isabel Rivera,Lindsay Rasmussen, Hannah McKay
With advances in wood product development and building code acceptance, mass timber structural systems have become viable alternatives to steel and concrete structural systems (Post 2015). These mass timber systems have environmental benefits, such as carbon sequestration ability and lower greenhouse gas emissions than steel and concrete systems. How can mass timber materials such as cross-laminated timber (CLT) reduce the environmental impacts of buildings, and how certain is this reduction? In...

Testing and Analysis of Hemlock Cross Laminated Timber
http://www.woodresearch.sk/wr/202005/12.pdf... [Raw Materials] [Journal Article] 2020
Wenbo Xie, Yewei Ding, Zheng Wang, Zizhen Gao, Tongyue Zhang, Yuhao Zhou, Yuhang He, Xiuling Huang
In this paper, the three-layer Canadian hemlock CLT panel was designed to test the elastic modulus and bending strength of CLT specimens by four-point bending method. The interlaminar shear of CLT specimens was tested by short-span three-point bending method. Strength, the shear strength and wood breaking rate of the CLT specimens were tested by the stair shear method. At the same time, the failure mode of the CLT board was analyzed. The main conclusions indicate that the test values of bending...

Comparison of Test Methodologies for Computing Bending and Shear Stiffness of Cross-Laminated Timber
https://www.astm.org/DIGITAL_LIBRARY/JOURNALS/TEST... [Standards/Building code] [Journal Article] 2020
Hojat Hematabadi, Daniel P. Hindman
Current testing methods for evaluating the out-of-plane bending and shear stiffness terms of cross-laminated timber (CLT) materials use a relatively long span panel. When new CLT layups and composites are proposed, especially when manufactured from pilot-scale facilities, the length requirement may be a barrier for material property evaluation. The purpose of this paper was to compare current bending and shear stiffness test methods of CLT with alternative forms, including a simultaneous calcula...

Acoustical Properties of Southern Pine Cross-Laminated Timber Panels
https://ascelibrary.org/doi/full/10.1061/%28ASCE%2... [Vibration/Acoustic Performance] [Journal Article] 2020
Daniel P. Hindman, Matthew V. Golden
Cross-laminated timber (CLT) is composed of a series of lumber layers placed orthogonally to create a thick panel. Advantages of CLT construction include reduced construction time, lighter structural elements, and reduced carbon footprint. As part of an effort to explore the use of a southern pine CLT panel for building code acceptance, the transmission loss (TL), associated sound transmission class (STC), normalized impact sound pressure levels (NISPL), and associated impact insulation class (I...

Seismic Fragility Estimates for Cross-Laminated Timber Platform Building
https://ascelibrary.org/doi/full/10.1061/%28ASCE%2... [Seismic Performance] [Journal Article] 2020
Md Shahnewaz, Yuxin Pan, M. Shahria Alam, Thomas Tannert
Cross-laminated timber (CLT) has been gaining popularity also in seismic regions, because of its low carbon footprint and potential cost-competitiveness with concrete and steel construction. Recent effort has focused on developing standardized design provisions for CLT buildings. In the study presented herein, incremental dynamic analysis (IDA) was performed on a six-story CLT platform-type building. A nonlinear numerical model was developed in OpenSees considering the CLT shear walls as elastic...

Seismic performance factors for cross-laminated timber shear wall systems in the United States
https://ascelibrary.org/doi/full/10.1061/%28ASCE%2... [Seismic Performance] [Journal Article] 2020
John W. van de Lindt, M. Omar Amini, Douglas Rammer, Philip Line, Shiling Pei, Marjan Popovski
Seismic force resisting systems based on cross-laminated timber (CLT) shear walls have garnered considerable attention for in mid-rise construction around the world. The purpose of this study was to determine seismic performance factors for CLT shear wall systems in platform type construction. These factors, namely, the response modification factors, R, overstrength factor, Ωo and deflection amplification factor, Cd, have been developed in this study for CLT walls and proposed for inclusion in A...