A glulam rivet as shown in Figure 5.14 below, is a high strength fastener which resembles a nail but has a flattened oval shank with a wedge shaped head. The rivet is driven through pre-drilled holes in a steel side plate until the tapered head is wedged into the hole.
In Canada, glulam rivets have become the fastener of choice for glulam members because performance is proven, and machining for acceptance of bolts or split rings is eliminated. US design codes do not yet provide information on the glulam rivet.
The development of the glulam rivet is the outcome of a long search for a new type of fastener particularily suited to laminated timber products. More than 40,000 rivets were tested either individually or in gropus to determine capacities.
Glulam rivets are used with Douglas Fir-Larch and Spruce-Pine glulam species categories in Canada but are not yet approved for use with solid timber.
Glulam rivets are manufactured of heat-treated steel in lengths from 40mm to 90mm (1-1/2" to 3-1/2").
Steel plates used in conjunction with rivets must have a minimum thickness of 4.8mm (3/16") and meet specific requirements for strength and ductility.
Glulam rivets have numerous advantages over other fasteners such as bolts and shear plates. They permit a greater load transfer per unit contact area than any other fastener, resulting in substantial saving in the size of steel side plates. Reduction in glued-laminated member sizes are possible in some instances since member design can be based on the entire cross-sectional area rather than the net area remaining after removal of wood material for the installation of fasteners such as bolts and split rings. Field assembly is simplified and the chance of alignment error is reduced in comparison to other types of fasteners.
Figure 5.14 Glulam Rivets