RESIDUAL WITHDRAWAL AND SHEAR STRENGTH OF SELF-TAPPING SCREWS INSERTED INTO GLUED LAMINATED TIMBER AFTER FIRE TEST

This study investigates the influence of fire exposure on the residual strength of the joint using a self-tapping screw (STS) in timber structure. Full-thread and partial-thread STSs joints of glued laminated timber were heated for one and two hours using a cone calorimeter, then withdrawal and shear tests on these joints were conducted to evaluate residual strength and stiffness after fire exposure. The result shows that the reduction of the withdrawal strength tends to be proportional to the heating time, whereas the shear strength decreases significantly due to change of the failure mode.