This manual is helpful for experts and novices alike. Whether you’re new to mass timber
or an early adopter you’ll benefit from its comprehensive summary of the most up to date
resources on topics from mass timber products and applications to tall wood construction
The manual’s content includes WoodWorks technical papers, Think Wood continuing
education articles, case studies, expert Q&As, technical guides and other helpful tools.
Click through to view each individual resource or download the master resource folder for
all files in one handy location. For your convenience, this book will be updated annually as
mass timber product development and the market are quickly evolving.
This Report presents the results from experimental studies of airborne sound transmission, together with an explanation of calculation procedures to predict the apparent airborne sound transmission between adjacent spaces in a building whose construction is based on cross-laminated timber (CLT) panels.
There are several types of CLT constructions which are commercially available in Canada, but this study only focused on CLT panels that have adhesive between the faces of the timber elements in adjacent layers, but no adhesive bonding the adjacent timber elements within a given layer. There were noticeable gaps (up to 3 mm wide) between some of the timber elements comprising each layer of the CLT assembly. These CLT panels could be called "Face-Laminated CLT PAnels" but are simply referred to as CLT panels in this Report.
Another form of CLT panels has adhesive between the faces of the timber elements in adjacent layers as well as adhesive to bond the adjacent timber elements within a given layer. These are referred to as "Fully-Bonded CLT Panels" in this Report.
This paper presents the first results of the flanksound project, a study promoted by Rotho Blaas srl regarding flanking transmission between CLT panels jointed with different connection systems. The vibration reduction index Kij is evaluated according to the EN ISO 10848 standard by measuring the velocity level difference between CLT panels. The performance of the X-RAD connection system is compared to the performance of a traditional connection system made of shear angle bracket and hold-down, both the configurations being tested with and without a resilient material placed between the construction elements. Concerning the traditional system, the influence of the difference sizes and types of fasteners - including the method of nailing or screwing - was also evaluated. The results of the measurements exposed in this work will hopefully contribute to the development of the acoustic design of timber buildings by providing a solid database of Kij values, which can be used to forecast the acoustic performance of the building according to the prediction models proposed in EN 12354-1.
The paper presents a numerical study conducted on a seven storey cross-laminated (X-lam) buildings equipped with translational Tuned Mass Dampers (TMD’s), as a technique for reducing the notoriously high drifts and maximum seismic accelerations of these types of structures. The building was modelled in the finite element software package Abaqus using 2D elastic shell elements and non-linear springs, which were implemented as an external user subroutine and properly calibrated to simulate the cyclic behavior of connectors in X-lam buildings. The used TMD device is linear, and placed on the top of the building. Time-history dynamic analyses were carried out under natural earthquake ground motions. Several comparisons between the response of the structure with and without TMD are presented, and the effectiveness and limits of these devices to improve the seismic performance of X-lam buildings are critically discussed.
Project contact is Erica Fischer at Oregon State University
This Faculty Early Career Development (CAREER) award will create innovative building technology that will enable mass timber modular construction as a building solution to many of the issues the nation's major cities face today. The architecture, engineering, and construction (AEC) sector is on the cusp of a significant disruption that will change the way buildings are manufactured, assembled, and designed, the catalyst of which is the integration of building information models (BIM) and automated construction and manufacturing. This disruption will significantly impact structural engineers. With the streamlining of building manufacturing, assembling, and design, engineers will need to take advantage of three opportunities: (1) design for constructability, (2) design for manufacturing, and (3) design for the whole life of the building (considering future modifications, maintenance, and easily replacing parts of the building). Modular construction, as one method to take advantage of these three opportunities, can address labor and housing shortages that exist in almost every U.S. city today and also can provide rapid construction methods for post-disaster reconstruction and additional patient care facilities. This research will contribute to the state of Oregon’s economy, which has made significant investments in mass timber production, manufacturing, and research. This research will be complemented through the development of best practices for using interdisciplinary, collaborative classroom environments to enhance engineering identities of underrepresented minorities and women at the graduate level. This award will support the National Science Foundation (NSF) role in the National Earthquake Hazards Reduction Program and the National Windstorm Impact Reduction Program.
The specific goal of this research is to develop a novel framework for robust and ductile mass timber modular construction that can be applied to buildings with varying lateral force resisting systems. Through this framework, the relationship between the rigidity of modular interconnections and overall structural behavior will be investigated. The research objectives of this project are to: (1) quantify the demands in interconnections that provide ductility when the building framing is subjected to combined gravity and lateral forces (seismic and wind); (2) quantify the impact of interconnection configuration and design on the ability of interconnections to meet the strength and serviceability performance criteria for mass timber high-rise modular buildings; (3) quantify ductility and overstrength for mass timber modular construction and explore applicability of conventional seismic performance factors and how these factors influence the adjusted collapse margin ratio for archetype buildings; (4) explore the influence of interconnection stiffness on the behavior of high-rise modular mass timber buildings subjected to wind demands; and (5) explore the relationship between team-focused and interdisciplinary educational practices with engineering identity and knowledge retention. New connection technology will be created and its contribution to the overall building behavior will be investigated through a rigorous testing plan and complex physics-based numerical simulations of archetype buildings subjected to combined gravity and lateral loads (seismic and wind). This research is a critical first step to develop innovative technology that will change how buildings are designed, manufactured, and assembled. This project will enable the Principal Investigator to establish interdisciplinary research, teaching, and mentorship in the area of mass timber and hybrid construction. This research will use the NSF-supported Natural Hazards Engineering Research Infrastructure (NHERI) Boundary Layer Wind Tunnel facility at the University of Florida. Experimental datasets will be archived in the NHERI Data Depot (https://www.DesignSafe-ci.org) and made publicly available.
The world tallest timber building with height of 45 meters, is planned for Bergen, Norway. In this master thesis the dynamic properties of the case building, as proposed by Sweco and Artec, are investigated. The proposed structural concept with a glulam frame and power-storeys, have never previously been built, and it is desirable to develop and understanding of the dynamic problems concerning this building. Previous work have shown problems with acceleration levels for tall timber building, mostly due to the material properties of timber. Timber has high flexibility and strength combined with low weight. The main aim of the work have been to build a 3D-model of the case building in a finite element program, where numerical methods can be used to find the dynamic properties of the building. The wind load and acceleration levels are investigated, and found to be reasonable compared to various criterions presented. The effect of the stiffness in the connections, as well as the use of apartment modules are investigated. In addition a dynamic analysis is run, and stochastic subspace state space system identification is used to verify the model. This can later be used for verification of the actual building when finished, and will be an important method to determine the actual damping and stiffness. Based on the findings in this work, the concept is assumed feasible, possible with some changes an even better concept is achieved. It will be exciting to see how Sweco will develop the concept further in the next planning phase.
Proceedings of the Institution of Civil Engineers - Construction Materials
The fire performance of heavy timber frame structures is often limited by the poor fire performance of its connections. Conventional timber connections, dowelled or toothed plate connections typically use steel as a connector material. In a fire, the steel parts rapidly conduct heat into the timber, leading to reduced fire performance. Replacing metallic connectors with alternative non-metallic, low thermal conductivity connector materials can, therefore, lead to improved connection performance in fire. This paper presents an experimental study into the fire performance of metal-free timber connections comprising a hot-pressed plywood flitch plate and glass-fibre-reinforced polymer dowels. The thermal behaviour of the connections at elevated temperatures is studied using a standard cone calorimeter apparatus and a novel heat transfer rate inducing system. The latter is a fire testing system developed at the University of Edinburgh. The mechanical behaviour of the connection during severe heating was also studied using an environmental chamber at temperatures up to 610°C. The results demonstrate that heat transfer in the non-metallic connections is governed by the thermal properties of the timber, resulting in significant enhancements in connection fire performance.