Axial slip-friction connections for cross-laminated timber
https://www.sciencedirect.com/science/article/pii/... [Connectors] [Journal Article] 2021
Dillon Fitzgerald, Arijit Sinha, Thomas H. Miller, John A.Nairn
Cross-laminated timber (CLT) rocking walls limit internal building forces and dissipate seismic energy mostly through severe connection damage and related wood crushing. While collapse-prevention and life-safety performance can be achieved, the connections and CLT walls are permanently damaged and may be unreliable for resisting aftershocks. Slip-friction connections (SFCs), also known as slotted-bolted connections, are highly resilient passive dampers originally developed for steel structures. ...

Reliability-based overstrength factors of cross-laminated timber shear walls for seismic design
https://www.sciencedirect.com/science/article/pii/... [Seismic Performance] [Journal Article] 2021
Angelo Aloisio, Massimo Fragiacomo
The ductile collapse mechanisms of structures should be less resistant than the brittle mechanisms to ensure a ductile seismic response: in this way, the ductile mechanisms activate before the brittle ones. This sort of chronological law of collapse is obtained in the design phase by providing a proper ”overstrength” to the brittle mechanisms. The realization of overstrength plays a crucial role in the design, and several studies endeavoured to estimate the best overstrength factors, defined as ...

Experimental study on orthogonal joints in cross-laminated timber with self-tapping screws installed with mixed angles
https://www.sciencedirect.com/science/article/pii/... [Connectors] [Journal Article] 2021
Justin R.Brown, Minghao Li, Thomas Tannert, Daniel Moroder
Cross-laminated timber (CLT) is increasingly being used in lateral load resisting systems of multi-storey buildings. Conventional in-plane CLT shear walls can be transformed into CLT core-wall structures with enhanced lateral strength and stiffness when the individual walls are connected orthogonally. In this paper, experimental studies are presented on orthogonal CLT joints with self-tapping screws (STS) installed with mixed angles, i.e. different installation angles between the STS axis and th...

A Specialized Data Crawler for Cross-Laminated Timber Information Resources
https://research.fs.usda.gov/treesearch/61364... [Other] [Journal Article] 2020
Ed Thomas; Omar Espinoza; Rahul Bora; Urs Buehlmann
The Internet is composed of more than 6.2 billion Web pages and grows larger every day. As the number of links and specialty subject areas grows, it becomes ever more difficult to find pertinent information. For some subject areas, special-purpose data crawlers continually search the Internet for specific information; examples include real estate, air travel, auto sales, and others. The use of such special-purpose data crawlers (i.e., targeted crawlers and knowledge databases) also allows the co...

Thermal performance and apparent temperature in school buildings: A case of cross-laminated timber (CLT) school development
https://www.sciencedirect.com/science/article/pii/... [Environmental Performance] [Journal Article] 2021
Timothy O. Adekunle
This paper examines the performance and apparent temperature in cross-laminated timber (CLT) school buildings. The research presents empirical data on the performance and provides the first set of data on apparent temperature in CLT school buildings. The development is in the New England area of the Northeast of the US. The investigation was conducted in the summertime. The principal aim of the investigation is to evaluate the performance, occupants’ comfort, apparent temperature, and other ther...

Characterizing flexural behaviour of panel-to-panel connections in cross-laminated timber floor systems
https://www.sciencedirect.com/science/article/abs/... [Mechanical Performance] [Journal Article] 2020
Sigong Zhang, Ying Hei Chui
Cross-laminated timber floor systems are currently designed by treating them as one-way systems. The one-way assumption is conservative but two-way model would overestimate the system stiffness if the presence of semi-rigid panel-to-panel connections is not properly considered in the analysis. These connections allow for partial transfer of bending moment from one panel to the adjacent panel. The primary objective of this research was to characterize the flexural behaviour of typical panel-to-pa...

Prediction of withdrawal resistance for a screw in hybrid cross-laminated timber
https://link.springer.com/article/10.1186/s10086-0... [Connectors] [Journal Article] 2020
Sung-Jun Pang, Kyung-Sun Ahn, Seog Goo Kang, Jung-Kwon Oh
The aim of this study was to predict the withdrawal resistance of a screw in hybrid cross-laminated timber (CLT) composed of two types of lamina layers. A theoretical model to predict the withdrawal resistance was developed from the shear mechanism between a screw and the layers in hybrid CLT. The parameters for the developed model were the withdrawal stiffness and strength that occurs when a screw is withdrawn, and the penetration depth of a screw in layers of a wood material. The prediction mo...

Hygrothermal characterization and modeling of cross-laminated timber in the building envelope
https://www.sciencedirect.com/science/article/abs/... [Moisture/Durability] [Journal Article] 2020
Steven Kordziel, Samuel V.Glass, Charles R. Boardman, Robert A.Munson, Samuel L. Zelinka, Shiling Pei, Paulo Cesar Tabares-Velasco
Cross-laminated timber (CLT) is a type of mass timber panel used in floor, wall, and roof assemblies. An important consideration in design and construction of timber buildings is moisture durability. This study characterized the hygrothermal performance of CLT panels with laboratory measurements at multiple scales, field measurements, and modeling. The CLT panels consisted of five layers, four with spruce-pine-fir lumber and one with Douglas-fir lumber. Laboratory characterization involved measu...

Bending, shear, and compressive properties of three- and five-layer cross-laminated timber fabricated with black spruce
https://jwoodscience.springeropen.com/articles/10.... [Raw Materials] [Journal Article] 2020
Minjuan He, Xiaofeng Sun, Zheng Li, Wei Feng
Cross-laminated timber (CLT) is an innovative engineering wood product made by gluing layers of solid-sawn lumber at perpendicular angles. The commonly used wood species for CLT manufacturing include spruce-pine-fir (SPF), douglas fir-larch, and southern pine lumber. With the hope of broadening the wood species for CLT manufacturing, the purposes of this study include evaluating the mechanical properties of black spruce CLT and analyzing the influence of CLT thickness on its bending or shear pro...

Evaluation of composite action in cross laminated timber-concrete composite beams with CFRP reinforcing bar and plate connectors using Digital Image Correlation (DIC)
https://www.sciencedirect.com/science/article/pii/... [Mechanical Performance] [Journal Article] 2021
S.A.Hadigheh, R. McDougall, C.Wiseman, L. Reid
This research proposes new types of shear connectors made of carbon fibre reinforced polymer (CFRP) composites for effective stress transfer between the timber and concrete sections in cross laminated timber (CLT)-concrete composite beams. New shear connectors are designed and made of bidirectional carbon fibre reinforced polymer (CFRP) composite plates and crossed CFRP reinforcing bars. The mechanical performance, bending stiffness, ductility, and interfacial slippage and strain of timber-concr...

Chicago Approves First Use of CLT, Dont Expect High-Rises Anytime Soon
https://www.enr.com/articles/44823-chicago-approve... [Markets] [Magazine/Newspaper Article] 2018
Jeff Yoders
The Great Chicago Fire of 1871 gave local building officials the jitters about the use of structural wood in commercial buildings. But a recent installation of cross-laminated timber decking in a one-story McDonald’s may mark a new era, at least for low-rise mass timber. Although the 19,000-sq-ft McDonald’s marks the first use of CLT in a Chicago building, officials say they are not about to allow tall mass timber buildings any time soon....

The Bending–Gradient theory for the linear buckling of thick plates: Application to Cross Laminated Timber panels
https://www.sciencedirect.com/science/article/pii/... [Mechanical Performance] [Journal Article] 2016
Olivier Perret, Arthur Lebée, Cyril Douthe, Karam Sab
In this paper, the linear buckling of a heterogeneous thick plate is studied using the Bending–Gradient theory which is an extension of the Reissner–Mindlin plate theory to the case of heterogeneous plates. Reference results are taken from a 3D numerical analysis using finite-elements and applied to Cross Laminated Timber panels which are thick and highly anisotropic laminates. First, it is shown that critical buckling loads are close to the material failure load which proves the necessity of a ...

Cross-laminated timber pilot project
https://des.wa.gov/about/projects-initiatives/cros... [Markets] [Magazine/Newspaper Article] 2017
Enterprise Services
In 2017, the Department of Enterprise Services oversaw a pilot project to build 20 kindergarten through third-grade classrooms using cross-laminated timber (CLT) in five school district sites in Washington. Using cross-laminated timber panels in construction is highly advantageous as it offers both design flexibility and lower environmental impacts....

Design and simulation of an automated robotic machining cell for cross-laminated timber panels
https://www.sciencedirect.com/science/article/pii/... [Other] [Journal Article] 2021
Emanuel Martinez Villanueva, Harshavardhan Mamledesai, Pablo Martinez, Peyman Poostchi, Rafiq Ahmad
Cross-laminated timber (CLT) is an innovative construction material that has brought advantages over traditional wood structures, reducing cost and lead time of buildings in recent years; yet CLT benefits primarily from offsite construction methods instead of automation or safety, while keeping the human onsite. The few advancements in automation for CLT panels have been in the implementation of dedicated CNC machines. Nevertheless, using CNC machines for machining CLT panels have disadvantages ...

Effect of ACQ treatment on surface quality and bonding performance of four Malaysian hardwoods and cross laminated timber (CLT)
https://link.springer.com/article/10.1007/s00107-0... [Moisture/Durability] [Journal Article] 2020
Nur Amira Adnan, Paridah Md Tahir, Hamdan Husain, Seng Hua Lee, Mohd Khairun Anwar Uyup, Mohamad Nasir Mat Arip, Zaidon Ashaari
The objective of this study is to determine the effects of alkaline copper quaternary (ACQ) treatment on the surface quality and bonding performance of four Malaysian hardwood species, namely batai, sesenduk, rubberwood and kedondong. The samples were impregnated with 2% ACQ preservatives and bonded with phenol-resorcinol–formaldehyde resin for cross laminated timber (CLT) fabrication. The changes in density and the retention of both ACQ and copper after the treatment were recorded. Surface roug...

Mechanical properties of cross-laminated timber (CLT) panels composed of treated dimensional lumber
https://ir.library.msstate.edu/handle/11668/14597... [Raw Materials] [Thesis/Dissertation] 2019
Sachin Tripathi
This research study investigates the effect of micronized copper azole type C (MCA-C) preservative system on the rolling shear (RS) properties of CLT. In the first part of research, bonding performance of CLT panels treated at two retention levels, 0.96 kg/m3 and 2.5 kg/m3, were evaluated. Three structural adhesive systems, melamine formaldehyde (MF), resorcinol formaldehyde (RF) and one-component polyurethane (1C-PUR) were used to assemble visually graded No. 2 2×6 southern yellow pine (SYP) lu...

Advancement in prediction of shear strength and stiffness of cross laminated timber beams
https://www.sciencedirect.com/science/article/pii/... [Mechanical Performance] [Journal Article] 2021
Mario Jeleča, Tihomir Dokšanovića, Hrvoje Draganića, Vlatka Rajčićb
Cross laminated timber (CLT) beams are mainly used within wall panels, but also standalone in design situations where cross layers have a reinforcing effect concerning stress perpendicular to the beam axis. The stress state in CLT beam members is complex and shear failure is mainly governed by stresses and strains acting in the crossing areas between orthogonally bonded laminations, known as shear failure mode III. The current model suggested for the next version of Eurocode 5 regarding shear st...

The influence of connection stiffness on the dynamic properties and seismic performance of tall cross-laminated timber buildings
https://www.sciencedirect.com/science/article/pii/... [Connectors] [Journal Article] 2021
Xiaoyue Zhang, Yuxin Pan, Thomas Tannert
It has become common practise to use Cross-laminated Timber (CLT) panels in shear wall applications in buildings around the world. Herein, the influence of the hold-downs, vertical and horizontal shear connections between the CLT panels on the period and stiffness of buildings was investigated. Two prototypes, 12-storey and 18-storey tall, of balloon-type construction were designed. To address the local seismicity of the chosen site in Vancouver, Canada, a range of crustal, subcrustal and subduc...

Structural design and mechanical properties analysis of bamboo-wood cross-laminated timber
https://bioresources.cnr.ncsu.edu/resources/struct... [Raw Materials] [Journal Article] 2020
Chao Li, Xilong Wang, Yizhuo Zhang
To explore the overall mechanical properties of bamboo-wood composite cross-laminated timber (BCLT), a simulation model of BCLT mechanical behavior based on the solid element was established using the finite element software ABAQUS. The actual four-point bending experiment was compared and analyzed with the finite element numerical simulation. The total curve error coefficient of the BCLT specimen at 18-mm displacement was 0.2988 while the interval was 0.5 mm. The error coefficient was 0.0178 wh...

Cross laminated timber (CLT) diaphragms under shear: Test configuration, properties and design
https://graz.pure.elsevier.com/en/publications/cro... [Design/Architectural aspects] [Journal Article] 2017
Reinhard Brandner, Philipp Dietsch, Julia Dröscher, Michael Schulte-Wrede, Heinrich Kreuzinger, Mike Sieder
The orthogonal structure of cross laminated timber (CLT) diaphragms under shear can cause three possible shear failure mechanisms: (i) gross-shear (in case of narrow-face bonded laminations), (ii) netshear and (iii) torsion. While the resistance against torsion has been investigated comprehensively, the determination of in-plane gross- and net-shear strength remains a challenging task. Whereas grossshear properties are proposed in analogy to glulam, for net-shear only properties derived from tes...