Structural performance of the finger-jointed strength of some wood species with different joint configurations

Abstract

This study was conducted to evaluate the effects of adhesive type, wood species, and finger joint configurations on structural performance of the finger joint. The wood species studied were oriental beech ( Fagus orientalis lipsky.), oak ( Quercus robur), Scots pine ( Pinus sylvestris lipsky.), poplar ( Populus tremula lipsk.) and Uludağ fir ( Abies bormülleriana Matff.) and adhesives were poly(vinyl acetate) (PVAc), Desmodur-VTKA (D-VTKA). However, there is little information available concerning the bending strength and modulus of elasticity for finger joints in these field. In this study, it was aimed to determine the bending strength and modulus of elasticity for finger joints. For this purpose, samples were tested according to the TS EN 310 standard. It was observed that the highest bending strength and modulus of elasticity were obtained in beech control (solid wood) samples. As for the finger joints, after the control samples, the highest bending strength value (57.4 N/mm 2) was obtained from Oriental beech wood samples having a 21 mm finger length and bonded with PVAc adhesive, the highest modulus of elasticity (8885.3 N/mm 2) was obtained from beech wood samples having a 21 mm finger length and bonded with PVAc adhesive. As a result of the effects of finger joints on bending strength and modulus elasticity test, if the length of finger joints increases up to 21 mm, the properties of bending strength increase.