CLT Shear Walls Anchored with Shear-Tension Angle Brackets: Experimental Tests and Finite-Element Modeling
https://ascelibrary.org/doi/full/10.1061/%28ASCE%2... [Connectors] [Journal Article] 2021
Giuseppe D’Arenzo, Daniele Casagrande, Andrea Polastri, Marinella Fossetti, Massimo Fragiacomo, Werner Seim
Due to the high in-plane stiffness and strength capacity of cross-laminated timber (CLT) panels, the mechanical behavior of CLT shear walls is mainly influenced by the mechanical performances of the connections. Several calculation models have been proposed considering the mechanical anchors effectiveness only along their primary direction. However, recent studies showed a relatively high stiffness and capacity of new typologies of angle brackets when subjected to uplift vertical loads, such as ...

House of natural resources – modal vibration tests and long-term monitoring
https://www.research-collection.ethz.ch/handle/20.... [Vibration/Acoustic Performance] [Report] 2021
Claude Leyder, Eleni Chatzi, Andrea Frangi
This report presents an innovative case-study building implementing four novel structural systems implementing innovative hardwood materials. The main structural system is a post-tensioned timber frame with columns in ash glulam and beams in hybrid ash-spruce glulam. The beams and columns are connected via a horizontal post-tensioning cable, which creates a semi-rigid moment frame. Furthermore, three different innovative slab systems are implemented inside the building, first a timber-concrete c...

Withdrawal Properties of Self-Tapping Screws in Japanese larch (Larix kaempferi (Lamb.) Carr.) Cross Laminated Timber
https://www.mdpi.com/1999-4907/12/5/524... [Raw Materials] [Journal Article] 2021
Junhua Xu, Shuangbao Zhang, Guofang Wu, Yingchun Gong, Haiqing Ren
With the increasing popularity of cross-laminated timber (CLT) constructions around the world, there have been attempts to produce CLT using local wood species in different countries, such as Japanese larch (Larix kaempferi (Lamb.) Carr.) in China. Thus, the need to investigate the connection performance also increases to support the design and construction of CLT buildings using local wood species. In this study, the withdrawal properties of three different types of self-tapping screws (STS), w...

Structural performance of CLT shear connections with castellations and angle brackets
https://www.sciencedirect.com/science/article/pii/... [Connectors] [Journal Article] 2021
Justin R. Brown, Minghao Li, Francesco Sarti
The advent of digital fabrication technologies and mass timber products such as cross-laminated timber (CLT) have facilitated the use of traditional carpentry joints in modern mass timber construction. Through contact bearing, mortise and tenon castellated joints can also provide high shear strength and stiffness between timber members when compared to connections using mechanical connectors/fasteners. In this study, a total of 29 connection specimens using carpentry castellations and six connec...

Whole-life embodied carbon in multistory buildings: Steel, concrete and timber structures
https://onlinelibrary.wiley.com/doi/full/10.1111/j... [Environmental Performance] [Journal Article] 2021
Jim Hart, Bernardino D'Amico, Francesco Pomponi
Buildings and the construction industry are top contributors to climate change, and structures account for the largest share of the upfront greenhouse gas emissions. While a body of research exists into such emissions, a systematic comparison of multiple building structures in steel, concrete, and timber alternatives is missing. In this article, comparisons are made between mass and whole-life embodied carbon (WLEC) emissions of building superstructures using identical frame configurations in st...

Rocking Behavior of High-Aspect-Ratio Cross-Laminated Timber Shear Walls: Experimental and Numerical Investigation
https://ascelibrary.org/doi/full/10.1061/%28ASCE%2... [Seismic Performance] [Journal Article] 2021
M. Omar Amini, John W. van de Lindt, Douglas Rammer, Shiling Pei
Cross-laminated timber (CLT) is a mass timber product that has recently garnered considerable attention for lateral-force resisting system (LFRS) applications. The main objectives of this study were to investigate the rocking behavior of a high-aspect-ratio (height/width) CLT shear wall without post-tensioning, and to validate a finite-element (FE) model based on the cyclic and dynamic response of the wall. To this point, high-aspect-ratio walls in the literature have primarily been post-tension...

Experimental study on lateral performance of glued-laminated timber frame infilled with cross-laminated timber shear walls
https://www.sciencedirect.com/science/article/pii/... [Seismic Performance] [Journal Article] 2021
Jianyang Xue, Guoqi Ren, Liangjie Qi, Chenwei Wu, ZhenYuan
This paper presents the results of a lateral performance study on glued-laminated timber frame (GLT) infilled with cross-laminated timber (CLT) shear walls by means of experimental method. Specially-designed steel connectors were installed at the frame-to-wall connections, which are used to provide reliable mechanism of force transmission for the structure. Lateral cyclic loading tests on this structural system were conducted, and the influences of opening size, opening form (e.g., door and wind...

Multi-objective optimization of CLT-concrete composite floor using NSGA-II algorithm
https://journal.augc.asso.fr/index.php/ajce/articl... [Alternative/Hybrid Configurations] [Journal Article] 2021
Minh Van THAI, Philippe Galimard, Sidi-Mohammed Elachachi, Sylvain Ménard
Cross-laminated timber (CLT) is an engineered wood product made of multiple glued layers in the form of a panel. Each CLT layer oriented perpendicular to the adjacent one. This type of structural element is particularly suitable for the application of a floor system. CLT-concrete composite (CCC) could be a solution for a long-span floor system of the mid-and high-rise building. This study focused on multi-objective optimization of the CCC floor using the genetic algorithm (NSGA-II). The three op...

Finite element analysis of alternative load paths to prevent disproportionate collapse in platform-type CLT floor systems
https://www.sciencedirect.com/science/article/pii/... [Other] [Journal Article] 2021
Johannes A.J. Huber, Hercend Mpidi Bita, Thomas Tannert, Sven Berg
Multi-storey buildings require mitigation of consequences of unexpected or accidental events, to prevent disproportionate collapse after an initial damage. Cross-laminated timber (CLT) in platform-type construction is increasingly used for multi-storey buildings, however, the collapse behaviour and alternative load paths (ALPs) are not fully understood. A 3D non-linear component-based finite element model was developed for a platform-type CLT floor system to study the ALPs after an internal wall...

In-Plane Shear Modulus of Cross-Laminated Timber
https://www.diva-portal.org/smash/record.jsf?pid=d... [Mechanical Performance] [Thesis/Dissertation] 2021
Sharifi, Jonas
Cross-laminated timber (CLT) is a building component used in walls, floors, roofs, or beams in a building. The advantages of using CLT as a building component are, among others, its high load-carrying capability and the possibility of pre-fabrication. The in-plane shear properties of a CLT panel are the in-plane shear modulus and in-plane shear load carrying capacity. This thesis is solely about the in-plane shear modulus and is intended to increase the understanding about the in-plane shear mod...

Hyperelastic hold-down solution for CLT shear wall
https://www.sciencedirect.com/science/article/abs/... [Connectors] [Journal Article] 2021
Hosein Asgari, Thomas Tannert, Mohammad Mehdi, Ebadib Cristiano Loss, Marjan Popovski
The use of cross-laminated timber (CLT) shear walls in tall buildings poses large demands on hold-downs (HD). While commonly used HDs behave as dissipative connections, the current Canadian Standard for Engineering Design in Wood recommends designing HDs as a non-dissipative connection. To satisfy this requirement, a hyperelastic elastomeric (rubber) HD was developed. Material level tests showed that the compressive behaviour of rubber layers relied on a dimensionless geometrical shape factor (S...

Performance of the hollow-core cross-laminated timber (HC-CLT) floor under human-induced vibration
https://www.sciencedirect.com/science/article/abs/... [Vibration/Acoustic Performance] [Journal Article] 2021
Haoyu Huang, Xiaoqi Lin, Junhui Zhang, Zhendong Wu, Chang Wang, Brad Jianhe Wang
In this study, an innovative hollow-core cross-laminated timber (HC-CLT) system was examined in terms of its human-induced vibration performance. Three types of HC-CLT floors were selected as the research objects, namely 3-ply HC-CLT, 5-ply HC-CLT with hollow cores along the transverse direction, and 5-ply HC-CLT with hollow cores along the longitudinal direction. By theoretical analysis, it was found that the hollow cores had a slight impact on the static bending stiffness, and HC-CLT floors ha...

CLT construction without weather protection requires extensive moisture control
https://journals.sagepub.com/doi/full/10.1177/1744... [Moisture/Durability] [Journal Article] 2021
Lars Olsson
This study examines how cross-laminated timber (CLT) constructions, including joints, connections and attachment points, are affected by precipitation during construction. The case studies are based on moisture content measurements and material sampling as well as microbiological analysis during the structure’s construction stage. The study does not include remediation control. The field measurements show microbiological growth in all buildings and almost all floor structures that were investiga...

Assessment of the Seismic Response of CLT Shear Walls Using the EEGBW, a Bouc–Wen Class Predictive Model
https://www.mdpi.com/2412-3811/6/4/55... [Seismic Performance] [Journal Article] 2021
Angelo Aloisio, Massimo Fragiacomo
The paper presents an application of the Extended Energy-dependent Generalized Bouc–Wen model (EEGBW) to simulate the experimental cyclic response of Cross-Laminated Timber (CLT) panels. The main objectives of the paper are assessing the sensitivity of the quadratic error between experimental and numerical data to the EEGBW parameters, showing the fitting performance of the EEGBW model in matching the experimental cyclic response of CLT panels, highlighting the stability of the model in nonlinea...

Mechanical Properties of Innovative Multifunctional Cross Laminated Timber
https://mediatum.ub.tum.de/doc/1608914/1608914.pdf... [Mechanical Performance] [Conference Paper] 2021
Matthias Arnold, Philipp Dietsch, Stefan Winter
This paper deals with wall elements from massive timber, which are modified for thermal activation – multifunctional cross laminated timber (multifunctional CLT). This wood product is currently developed towards maturity for application, by determining e.g. the mechanical properties. The multifunctional CLT elements feature channels in which conditioned air circulates, reducing the cross-sectional area. In this paper we investigate e.g. the compression strength and stiffness, the buckling load, ...

Development of a uniaxial hysteretic model for dowel-type timber joints in OpenSees
https://www.sciencedirect.com/science/article/abs/... [Connectors] [Journal Article] 2021
Hanlin Dong, Minjuan He, Xijun Wang, Constantin Christopoulos, Zheng Li, Zhan Shu
Dowel-type joints are commonly used as shear connections in many types of timber structures. The load-deformation hysteretic behavior of dowel-type joints usually dominates the structural seismic performance. In this paper, a novel phenomenological uniaxial hysteretic model for dowel-type timber joints is developed. It has the following features: (1) the model fits various dowel-type joints including nails, screws, and bolts, as well as grouped joints, and agrees well with experimental data; (2)...

Evaluation of Flexural Performance According to the Plywood Bonding Method of Ply-Lam CLT
https://www.koreascience.or.kr/article/JAKO2021117... [Alternative/Hybrid Configurations] [Journal Article] 2021
Choi, G. W., Yang, S. M., Lee, H. J., Kim, J. H., Choi, K. H., & Kang, S. G.
The purpose of this study is to optimize the bonding method of the plywood suitable for cross-laminated timber (CLT) with plywood as a core by analyzing the flexural performance and failure mode according to the lamina species, the method of bonding plywood in the longitudinal direction, and whether or not adhesive is applied to the joint. In the case of the Douglas fir lamina layer, the modulus of elasticity decreased by about 11.5% due to longitudinal bonding, and the modulus of rupture increa...

Improved Strength and Stiffness Characteristics of Cross-laminated Poplar Timber Columns
https://iranjournals.nlai.ir/handle/123456789/7911... [Mechanical Performance] [Journal Article] 2021
J. Bhat
Timber apart from being a cheap construction material possesses numerous environmental advantages, which makes it one of the highly sought construction material, particularly for moderately loaded residential structures. Timber due to the easy cultivation of timber trees can be made available in abundance. Thus, can serve as an efficient and sustainable building material, provided its structural potential is tapped fully. In this study, various performance improvement techniques have been used ...

Using existing site surveillance cameras to automatically measure the installation speed in prefabricated timber construction
https://www.emerald.com/insight/content/doi/10.110... [Other] [Journal Article] 2021
Alireza Ahmadian Fard Fini, Mojtaba Maghrebi, Perry John Forsythe, Travis Steven Waller
Measuring onsite productivity has been a substance of debate in the construction industry, mainly due to concerns about accuracy, repeatability and unbiasedness. Such characteristics are central to demonstrate construction speed that can be achieved through adopting new prefabricated systems. Existing productivity measurement methods, however, cannot cost-effectively provide solid and replicable evidence of prefabrication benefits. This research proposes a low-cost automated method for measuring...

Development of cross laminated timber-cold-formed steel composite beam for floor system to sustainable modular building construction
https://www.sciencedirect.com/science/article/abs/... [Alternative/Hybrid Configurations] [Journal Article] 2021
Satheeskumar Navaratnam, Deighton Widdowfield Small, Perampalam Gatheeshgar, Keerthan Poologanathan, Julian Thamboo, Craig Higgins, Priyan Mendis
Cold-formed steel (CFS) and cross-laminated timber (CLT) structural components are widely employed in low- to mid-rise and modular building constructions. These two materials have individually shown to be lightweight, and possess relatively higher strength characteristics. Owing to these benefits, composite CLT-CFS sections can be used as structural elements and possibly be employed in modular buildings with enhanced structural performances. This paper presents the development of CLT-CFS composi...