WOOD RESEARCH Volume 62, Number 3, 2017
Yo-Jin Song, Soon-Il Hong, Jin-Suk Suh, and Sang-Bum Park

Strength performance evaluation of moment resistance for cylindrical-lvl column using GFRP reinforced wooden pin

In this study, Moment resistance performance of column-beam joints using cylindrical laminated veneer lumber (LVL) column and glulam beam were evaluated. Two types of jointing methods – Type-A, in which the beam is put on the end side of column and Type-B, in which the beam is inserted into column – were applied. As a result of Type A, Moment resistance of the cylindrical-LVL column jointed with drift pins was shown to be 67 % higher than that of the larch log column jointed with drift pins. The larch log column jointed with GFRP Plate reinforced wooden pins was shown to be 14 % higher than that jointed with drift pins. In Type-B joint, the rotational stiffness of two specimens were 139.4 kN•m/rad. (Non-reinforced specimen) and 272.2 kN•m/rad. (reinforced specimen), respectively, and reinforced specimen was 95 % higher than Non-reinforced specimen. Based on this result it was assured that glass fiber reinforcement is able to reinforce the column.

WOOD RESEARCH Volume 63, Number 1, 2018
Yo-Jin Song and Soon-Il Hong

Performance evaluation of the bending strength of larch cross-laminated timber

A bending strength test was carried out on the strip-type cross-laminated timber (3 layers) that was combined differently by the cross-sectional annual ring orientation of the laminae under the same modulus of elasticity combination. In addition, the bending modulus of elasticity and the maximum bending moment predicted using the gamma method were compared with the results of the actual test. The result of the bending strength test showed no significant difference in bending strength among the specimens combined according to the annual ring orientation. Furthermore, when the outer tension layer of the cross-laminated timber was strengthened with a glass-fiber-reinforced plastic plate (volume ratio: 1.2%), the modulus of elasticity and the modulus of rupture increased by 4.2% and 16.3%, respectively. The ratios of the prediction results for the bending modulus of elasticity and the maximum bending moment by the gamma method to the actual test values were 1.01 and 0.96 on average, respectively, indicating that the two values were almost identical.

WOOD RESEARCH Volume 64, Number 2, 2019
Yo-Jin Song, In-Hwan Lee, and Soon-Il Hong

Evaluation of horizontal shear performance of larch CLT walls according to the edge connection shape

In this study, cyclic tests were performed on the larch CLT shear walls depending on the half lap reinforcement of half-lap connections and reinforced plywood of spline connections in order to evaluate the horizontal shear performance of the larch CLT walls. The test results show that there is no difference in residual strength depending on the reinforcement of half-lap connection, but their initial stiffness has been increased by 9%. There was no significant difference either in the residual strength of double spline connections depending on the application of reinforced plywood, while the spline reinforcement has failed to increase initial stiffness. All of the larch CLT walls constructed according to the edge connection shape were measured to have a strength reduction ratio of less than 10% in each horizontal displacement intervals and an equivalent viscous damping ratio of less than 10% for energy dissipation in the initial and final horizontal displacement intervals, thereby confirming that their excellent horizontal shear performance and seismic performance.