AWC Conducts Full-Scale CLT Diaphragm Tests

Oct 13, 2020

CLT Diaphragm TestLEESBURG, VA. – The American Wood Council (AWC) has successfully completed two full-scale cross-laminated timber (CLT) diaphragm tests to provide strength and deformation data important for evaluating CLT diaphragm resistance to lateral wind and earthquake forces. The tests were completed at Weyerhaeuser’s ISO 17025 accredited test facility in Federal Way, Washington.

"This research used full-scale seismic testing to test a CLT diaphragm supported by wood members, in this case glued laminated timber framing,” said AWC Vice President of Engineering Bradford Douglas, P.E. “The results showed the diaphragm performed well with diaphragm strength exceeding targets and load-deformation response primarily governed by connection behavior. This testing used the CLT diaphragm design approach incorporated in the 2021 Special Design Provisions for Wind and Seismic which relies upon the design of wood members and connections in accordance with applicable requirements of the 2018 National Design Specification® for Wood Construction.”

The test results will also allow researchers to identify potential opportunities for optimization to further advance use of this new versatile technology in floors and roofs of building structures.

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.