Project Title: Flexural Behaviour of Glulam-to-CLT Composite-Section Beams at both Normal and Elevated Temperatures.

Wood has long been in application as a competent construction material due to its beauty, economy, and ease of construction. However, in fire conditions light-wood structural members, if not treated, can perform very poorly. On contrary, heavy timber sections such as those made of glued-laminated timber (Glulam) and cross-laminated timber (CLT) can retain their strength for a longer period of time in fire, since heavy wood sections lose strength slowly and only as material is lost through surface charring. In addition, those new engineered-wood products offer a strong combination of environmental performance and sustainability. Nevertheless, concerns about their structural fire performance have resulted in efforts to restrict or regulate their use through prescriptive provincial and national regulations. CLT, a new engineered-wood product to North America, was developed in Austria more than two decades ago; however, it has not been put inot application here in Canada until only a few years ago. CLT panels are composed of alternating layers of wooden boards stacked at ninety degree angle to each other, and subsequently wither glued together or mechanically fastened to form large-size panels. Those panels are assembled to form the basis of a building system, as they can be used as walls, floors, and roof slabs. One of the great advantages of those panels is their good thermal and sound insulation, as well as their excellent behaviour under seismic loading.  

 A number of CLT buildings have recently been built in Canada and others are currently under construction, all used the alternative compliance approach of the building codes, since more research is needed to develop new provisions in our building codes and design standards that specifically address the design of CLT structural members. Besides using CLT panels in the construction of new buildings, they also can be effectively utilized in retrofitting and rehabilitation of wood floor systems. In this type of application, CLT panels can be connected to supporting timber beams using different kinds of mechanical fasteners, e.g., screws and dowels. Strong connection between CLT panels and timber beams creates composite action that increases the flexural stiffness of the connected parts.       

In case of new constructions, CLT panels can be fastened to beams that are made of new engineered-wood products, such as glued-laminated (Glulam) timber. Glulam is a structural timber product manufactured by gluing together individual pieces of wood under controlled heat and pressure conditions, and then it can be used in manufacturing columns, beams, or curved members, such as in arches.

The main objective of this reserach project is to investigate the structural behaviour of Glulam-to-CLT composite-section beams at both normal and elevated temperatures. Different study parameters are investigated, i.e., screw diameters, pitch, and angle of inclination.