Improvement of glued-in-rod joint system using compressed wooden dowel

The purpose of this study was to develop eco-friendly and high-performance glued-in-rod (GIR) joints using compressed wood (CW), which has higher tensile strength than normal hardwood, instead of conventional wooden dowels. To explore the bonding performance of the dowel and base material, punching shear tests were performed and relationships were established between the density of CW dowel and punching characteristics. Pull-out tests of GIR joints were performed and results were compared with those derived from a mechanical model to evaluate the influence of insertion length of dowel and to define its optimized length. The results indicate that CW dowel has almost the same bonding performance in the density range 330-1000 kg m(-3). Hence, CW as a dowel material in GIR joints has a high application potential. Pull-out tests of GIR joints showed that the insertion length of dowel in GIR joints with the CW-67 dowel is the best if the length is 10 times larger than its diameter. In addition to its satisfactory bonding performance, CW dowels have excellent tensile characteristics.