Demonstration of a Cost-Effective CLT Panel Capable of Resisting DOS/DOD Design Basis Threats – Phase I

https://research.thinkwood.com/en/permalink/catalogue3167
Year of Publication
2022
Topic
Mechanical Properties
Material
CLT (Cross-Laminated Timber)
Organization
Karagozian & Case Inc.
Year of Publication
2022
Material
CLT (Cross-Laminated Timber)
Topic
Mechanical Properties
Keywords
Blast
Ballistic
Forced Entry
Weathering
Research Status
In Progress
Notes
Forest Service/USDA Wood Innovations Grants Recipient Point of Contact: Mark Weaver Location: Glendale, California
Summary
Buildings used by many federal agencies including the Department of State (DOS) and Department of Defense (DOD) often must meet blast, ballistic, and forced entry (FE) design requirements to mitigate physical hazards associated with terrorism. Historically, these buildings have used concrete and steel construction to protect occupants from these threats. However, the emergence of mass timber construction, particularly cross-laminated timber (CLT), presents a sustainable, modular, and cost-effective alternative building material for high-security infrastructure. Previous studies involving blast, ballistic, and FE testing on CLT indicated that CLT provides much greater protection than conventional wood construction but that it needs some form of reinforcement to comply with more stringent antiterrorism requirements and broaden the use of wood structures in federal facilities. The proposed effort builds on the results of a previous Wood Innovation Grant (21-DG-11052021-242) that constructed full-scale CLT panels with steel reinforcement and tested these panels under quasi-static four-point bending testing. This effort involves two types of investigation to further demonstrate the effectiveness of reinforced CLT panels under extreme conditions: (1) weathering and (2) blast. The weathering testing will investigate whether reinforced CLT panels maintain their dimensional stability and do not delaminate under exposure to temperature cycling and moisture conditions during construction. Ideally, the blast testing will demonstrate the ability of reinforced CLT to exhibit a ductile post-peak response as well as be capable of supporting its axial load following a blast event. A primary focus of the proposed effort will be to ensure the developed reinforced CLT panel designs are competitive with existing DOS-compliant protection construction systems from both a cost and weight perspective. The project team includes an American CLT manufacturer (SmartLam) to quickly assess the cost impacts associated with a reinforced CLT. Additionally, representatives from the DOS that are familiar with federal facility protective design requirements will be consulted to ensure programmatic, procurement, and detailing issues are considered during reinforced CLT panel design development.
Less detail