Creep of moisturized oak dowels under tensile loading

0509037 - ÚTAM 2020 RIV PT eng C - Conference Paper (international conference)
Hasníková, Hana - Kunecký, Jiří - Hataj, M. - Milch, J. - Kloiber, Michal
Creep of moisturized oak dowels under tensile loading.
Proceedings of the International conference on structural health assessment of timber structures, SHATiS’2019. Guimarães: Universidade do Minho, 2019 - (Branco, J.; Poletti, E.; Sousa, H.), s. 428-436. ISBN 978-989-54496-2-0.
[International conference on structural health assessment of timber structures, SHATiS’2019 /5./. Guimarães (PT), 25.09.2019-27.09.2019]
R&D Projects: GA TA ČR(CZ) TJ01000412; GA MK(CZ) DG16P02M026
Keywords : oak dowel * creep * experimental testing * moisture * historical structures
OECD category: Construction engineering, Municipal and structural engineering

Timber joints intended for replacement of decayed parts of historical timber structures suffer long-term effects from loading and viscoelastic phenomena. Stiffness of the joints is of crucial importance especially in members loaded by tensile forces, such as tie beams, where deflection could redistribute the forces in the original structure or induce disadvantageous stresses in the underlying masonry. Under tension, regardless of using steel or wooden dowels, the joints instant deflection together with creep could attain the range of few millimeters. In the paper a creep loading under a specific stress level (30 % of ultimate load capacity) of moisturized oak dowels is investigated. For the purpose, a creep testing device with controlled environment and simultaneous long-term dead load application has been constructed. The loaded specimens were the chains of planks joined together using single-shear oak dowels having various moisture content and the dowel diameter of 24 mm. They were loaded in parallel-to-grain direction of the planks and perpendicular-to-grain for the dowels as they appear in structures. Testing time was set to one month, because such a period is considered to be crucial for the creep response. Creep relation to moisture content and level of applied dead load has been documented, creep stages quantified, and the final long-term deflection was assessed.
Permanent Link: http://hdl.handle.net/11104/0299843