Moment Behavior of Laminated Beam-Column Joint with Glued-in Steel Rods Manufactured from Small-Diameter Larch Logs

To promote the structural use of small-diameter logs often harvested in Korea, the use of laminated members with square timber obtained from small-diameter logs as their elements is being considered. With the objective of improved strength, elements obtained from large-diameter logs were combined with elements obtained from small-diameter logs. In this study, the authors prepared beam-column joints using these laminated members and examined their moment resistance performance. To join a laminated beam and a laminated column, the authors used glued-in steel rods. The results of a mechanical test on the moment-deformation angle relationship showed that from the initial force to the failure point, the behavior was mostly linear. Moreover, the rotational stiffness was approximately 900 kNm/rad, the maximum moment was approximately 30 kNm, and the joint efficiency for deformation was approximately 0.8. It was revealed that a significant amount of the deformation in this specimen resulted from the bending deflection of the laminated column. The authors also estimated the rotational stiffness and maximum moment through linear analysis. The slip properties of the deformed bar, compression properties perpendicular to grain of the laminated column, and bending properties of the laminated column were taken into consideration. The estimated results were mostly consistent with the experimental results. As a method to easily understand the moment resistance performance of these joints, the present proposed estimation method should be effective.