A new shear connection system was tested in order to be used in off-site manufactured cassette floor elements made with glulam beams and Cross Laminated Timber (CLT) panels. The shear connection proposed is made with double-sided punched metal plate fasteners, connecting CLT and glulam members to form a T-cross-section. Due to the lack of withdrawal capacity of punched metal plate fasteners, the shear connection must be secured with screws to resist separations forces which may occur between the members in the floor element.
Shear tests were performed on glulam-CLT joints made with double-sided punched metal plate fasteners and with inclined self-tapping screws as reference cases to compare to joints with both fastener types combined. Each fastener type is characterised by a specific load-slip curve and different values for the yield slip, slip at maximum load and failure slip. These parameters can be used to evaluate the compatibility of the different fasteners and their combined effect in a joint. The test results show that there is a significant contribution from both the double-sided punched metal plate and inclined screw fasteners to the strength and stiffness of the combined joints.
Due to the fact that the individual fasteners reach their maximum load for different slip values, the load-carrying capacity of joints with combined fasteners is somewhat lower than the sum of the individual fasteners load-carrying capacities. The slip modulus of the combined fasteners may be estimated as the sum of the respective slip modulus of each fastener due to the compatible behaviour of the fasteners in the serviceability limit state.