Evaluation of Shear Performance of Screw Joints Reinforced with Adhesives for Floor Joists

The practical method for evaluating improvement of the shear performance of floor joints to horizontal diaphragms was examined when using adhesives as compared to designs for screws alone, assuming that the design of the stressed-skin panel used Laminated Veneer Lumber (LVL) for both the flange and the web. The adhesive was spread around the screw joint, and single shear tests were done. Then the maximum loads, loads at yield point, and stiffness were compared to the condition with a gap in the shear plane and the condition of water soaking the test piece after curing. As a result, it became possible to calculate the reduction factor of the screw joint and the adhesive joint independently, and it became clear that evaluation of the condition with a gap in the shear plane is needed, to obtain the just appraisal for the design where adhesive is spread on the entire shear plane.