LEESBURG, VA. – The American Wood Council (AWC) completed testing of connections used in recent full-scale tests of cross-laminated timber (CLT) diaphragm. The latest test results indicated that the connections performed better than expected, resulting in higher than expected shear capacities of the CLT diaphragms.
“In order to fully understand the full-scale CLT diaphragm test results done last year, we needed to better understand some of the connections that were used in the full-scale tests. The results of these latest tests could lead to changes allowing more efficient CLT diaphragm designs in the future,” said AWC Vice President of Engineering Bradford Douglas, P.E.
The tests were conducted in support of new criteria for design of the CLT diaphragm design approach included in the 2021 Special Design Provisions for Wind and Seismic (SDPWS). The connection testing augments the full-scale diaphragm testing completed in 2020 and focuses on the structural performance of the individual connections of the diaphragm, designed in accordance with the National Design Specification for Wood Construction.
The connection testing was conducted at Weyerhaeuser’s ISO 17025 accredited test facility in Federal Way, Washington and included lateral, withdrawal, and bearing strength per standard methods. The 2021 SDPWS is referenced in the 2021 International Building Code.
AWC is an ANSI-accredited standards developer and the National Design Specification® (NDS) for Wood Construction and Special Design Provisions for Wind and Seismic (SDPWS) are developed through a consensus process under the AWC Wood Design Standards Committee. The SDPWS-2021 and the NDS-2018 are reference design standards in the 2021 International Building Code.