Flexural Properties of Downscaled Dowel-Type-Fastener Laminated Timber

O. Ogunrinde¹ , M. Gong² , Y.H. Chui³ , L. Li⁴

Section:Research Paper, Product Type: Journal-Paper
Vol.5 , Issue.11 , pp.98-104, Nov-2019

Online published on Nov 30, 2019

Copyright © O. Ogunrinde, M. Gong, Y.H. Chui, L. Li . This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
 

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Abstract :
Use of nail-laminated timber (NLT) in structural buildings has steadily increased in recent years, which calls for a need to optimize the design of its assemblies. This study was aimed at examining the effect of nailing patterns on the flexural properties of unspliced NLT specimens. To reach this, the modulus of elasticity (MOE) of each lumber piece was determined using a long-span centre-point bending test to ensure that all pieces of lumber used were in the same MOE range. A type of downscaled NLT specimen was designed and fabricated using nails, which were 30 mm in thickness, 44 mm in width, and 730 mm in length. The 3D ring shank nails used were 30 mm in length and 2.4 mm in diameter. Three nail spacing (i.e. 60, 85 and 110 mm) were used in fabrication of the NLT. The glue-laminated timber (GLT) specimens of the same dimensions were manufactured for comparison purposes. The specimens were tested under four-point bending. The apparent modulus of elasticity MOEapp and apparent modulus of rupture MORapp of each specimen were measured. It was found that the solid group had the highest MOEapp of 10,836 MPa, while the NLT group of 60-mm-nail-spacing had MOEapp of 10,145 MPa and the NLT group of 110-mm-nail-spacing had the lowest MOEapp of 9,254 MPa. As for the MORapp, the GLT group had the highest value of 88 MPa followed by the 60-mm-nail-spacing NLT group (75 MPa) and the 110 mm-nail-spacing NLT group (69 MPa). The 60-mm-nailing NLT group appeared to exhibit the best performance, which was recommended for full-size specimen tests.

Key-Words / Index Term :
Nailing pattern, laminated timber, ring shank nail, stiffness, apparent modulus of elasticity, and apparent modulus of rupture

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