Lack of research and design information for the seismic performance of balloon-type CLT shear walls prevents CLT from being used as an acceptable solution to resist seismic loads in balloon-type mass-timber buildings. To quantify the performance of balloon-type CLT structures subjected to lateral loads and create the research background for future code implementation of balloon-type CLT systems in CSA O86 and NBCC, FPInnovations initiated a project to determine the behaviour of balloon-type CLT construction. A series of tests on balloon-type CLT walls and connections used in these walls were conducted. Analytical models were developed based on engineering principles and basic mechanics to predict the deflection and resistance of the balloon-type CLT shear walls. This report covers the work related to development of the analytical models and the tests on balloon-type CLT walls that the models were verified against.
Project contact is Kadir Sener at Auburn University
While the emphasis in the timber industry understandably focuses predominately
on complete mass timber structures, opportunities to substantially expand the mass timber
market exist using composite timber-steel systems. Timber-steel composite systems have a
high potential to be an economically, architecturally, and structurally feasible system to
expand the usage of timber panels for mid-rise and high-rise structures where mass timber is
currently not a feasible option. In this novel system, prefabricated timber panels replace
reinforced concrete slabs to provide the floor and diaphragm elements that work compositely
with steel beams and to improve the structural performance compared to either individual
material. Considerable testing effort outside the US has explored the feasibility and benefits
of these composite systems. This has led to implementation of this novel system on a number
of international construction projects. However, the topic has not been assimilated by
researchers and practitioners in the US. Hence, this proposal focuses on identifying and
removing barriers and providing design guidance on using steel-timber composite systems in
US construction. The proposal: (i) Engages a diverse body of stakeholders in an advisory panel
and workshop, (ii) Completes engineering-based testing and analysis to demonstrate
feasibility, (iii) Performs constructability studies (i.e., construction cost, speed, env. impact),
and (iv) Establishes preliminary design guidelines and approaches. The goal of the project will
be to demonstrate the performance and economy of a timber-steel composite system(s) and
establish preliminary design guidelines and approaches for target stakeholders. Ultimately,
the project will develop experimentally validated design-detailing configurations and
establish design specifications for new mass timber markets in multiple construction sectors.
Project contact is Keri Ryan at University of Nevada, Reno
A landmark shake table test of a 10-story mass timber building will be conducted in late 2020. The test program, funded by other sources, will help accelerate the adoption of economically competitive tall timber buildings by validating the seismic performance of a resilient cross-laminated timber (CLT) rocking wall system. In this project, we leverage and extend the test program by including critical nonstructural components and systems (NCS). Including NCSs, which are most vulnerable to rocking induced deformations of the CLT core, allows investigation of the ramification of this emerging structural type on building resiliency. Quantifying interactions amongst vertically and horizontally spanning NCSs during earthquake shaking will allow designers to develop rational design strategies for future installation of such systems. The expected research outcomes are to expand knowledge of rocking wall system interactions with various NCS, identify NCS vulnerabilities in tall timber buildings, and develop solutions to address these vulnerabilities. Moreover, this effort will greatly increase visibility of the test program. The results of this research will be widely disseminated to timber design and NCS communities through conference presentations, online webinars, and distribution to publicly accessible research repositories.
Project contact is Chris Pantelides at the University of Utah
A mass timber buckling-restrained braced frame is proposed to enhance the seismic resilience of mass timber buildings. Constructed using wood generated from the national forest system, the mass timber buckling-restrained brace will be integrated with a mass timber frame for structural energy dissipation under seismic or wind loads. The team will improve and optimize the design of structural components based on feedback from a real-time health monitoring system. Outcomes include guidelines for a lateral force resisting system of mass timber buildings in high seismic or wind regions.
Sustainable Northwest (SNW) and Hacienda Community Development Group (HCDC), both based in Oregon, have proposed a plan to demonstrate pathways for building affordable housing with regionally sourced mass timber. In response to the region’s housing shortage, the partners’ proposal demonstrates the use of mass timber products while supporting efforts to educate stakeholders on wood product companies and forest restoration. The project outlines a plan to explore financing options, build one or more prototypes, and perform a structural material life cycle analysis.
The anticipated growth and urbanization of the global population over the next several decades will create a vast demand for the construction of new housing, commercial buildings and accompanying infrastructure. The production of cement, steel and other building materials associated with this wave of construction will become a major source of greenhouse gas emissions. Might it be possible to transform this potential threat to the global climate system into a powerful means to mitigate climate change? To answer this provocative question, we explore the potential of mid-rise urban buildings designed with engineered timber to provide long-term storage of carbon and to avoid the carbon-intensive production of mineral-based construction materials.
There has been no research to date exploring whether timber products can provide effective thermal capacitance in residential or commercial construction. This research is exploring the use of unique mass-timber products to provide a new form of thermal performance capacitance
within the built fabric of new and existing homes. The development of mass timber products is a new paradigm in material and building science research in Australia, requiring the accounting for carbon emissions, carbon sequestration, material embodied energy and material thermal properties for this renewable resource. This paper focuses on the results from preliminary building simulation studies encompassing house energy rating simulations and a comparative analysis of embodied energy and carbon storage for a series of house plans in Australia.