International Conference of the Architectural Science Association
Greenhouse gas (GHG) emissions have increased for the last three consecutive years in Australia, and this directly threatens our ability to meet our 2030 GHG emission reduction target under the Paris Agreement. Despite progress in reducing building-related GHG emissions, little focus has been placed on the indirect GHG emissions associated with building material manufacture, and construction. Cross laminated timber (CLT) is an alternative construction material that has been subject to numerous comparison studies, including many life cycle assessments (LCA). The aim of this paper is to provide a review of the recent literature on the environmental performance of CLT construction for Medium Density Residential (MDR) buildings and to identify knowledge gaps that require further research. Studies reviewed were sourced from web-based research engine, direct searches on global wood promotion websites, and the review was limited to peer reviewed publications. This review provides a useful basis for informing the exploration of important gaps in the current knowledge of how CLT buildings perform from an environmental perspective. This will ensure a comprehensive understanding of the environmental benefits of CLT construction and inform decision-making relating to structural material selection for optimising the life cycle GHG emissions performance of buildings.
New Zealand Society for Earthquake Engineering Conference
April 27-29, 2017, Wellington, New Zealand
Framework is a 12-story, 140ft (43m) tall mixed use building to be constructed almost entirely out of mass timber, including both the gravity and lateral forceresisting systems, in a region of high seismicity in the United States (Portland, Oregon). Utilizing performance-based seismic design and nonlinear response history analysis, the structure’s rocking/re-centering cross laminated timber walls were designed for enhanced, beyond-code-level seismic objectives. These enhanced objectives were targeted through more stringent criteria on deformation-controlled elements, design for replacement of energy dissipaters, limitations on residual drift, and a project-specific testing program completed at Oregon State University and Portland State University.
The momentum behind construction of mass timber buildings in the United States provides an opportunity to promote resilient/low-damage design which is consistent with the sustainability goals of many of these projects. This also follows naturally from the inherent rocking/re-centering behavior of mass timber walls. Furthermore, extending rocking mass timber walls to taller buildings is feasible; however, it requires an additional level of thoughtful design, explicit analysis and testing, and careful detailing, including consideration of the effective shear modulus of CLT, wall shear amplification due to higher mode effects, deformation compatibility of gravity connections, and CLT diaphragms.
In this project, a conceptual but realistic 20-storey building of hybrid construction incorporating massive timber panels and other structural materials was identified. The project team, consisting of three practicing consultants and 6 graduate student and post-doctoral researchers from NEWBuildS, undertook an analysis and engineering design of the demonstration building. An advisory group that includes FPInnovations scientists, NEWBuildS supervisors of the graduate students and Post Doctoral Fellows, provides technical support to the project team. The performance attributes addressed in the project were structural performance under seismic and wind load, fire resistance and building envelope. . This publication documents the analysis and design of the demonstration building, and identifies technical issues that require further study.