Mechanical Properties of Dowel Laminated Timber Beams with Connectors Made of Salvaged Wooden Materials

Abstract

The endeavor toward eco-friendly building materials has led to the development of dowel laminated timber (DLT), a product in which sawn timber boards are laminated using hardwood dowels. DLT reduces the need for metallic fasteners and synthetic adhesives, however, its application as a beam element is challenged by the relatively low bending stiffness resulting from the low composite action. In this research, we evaluated the effectiveness of replacing hardwood dowels with connectors made from salvaged engineered wood products to improve the bending stiffness and further enhance the environmental benefits of DLT beams. 60 push-out shear tests were performed on three-layer connections laminated using dowels and tenons from salvaged plywood, salvaged laminated veneer lumber, and solid Oak as a reference. From selected connectors, three-layer beams were then fabricated and tested under a four-point bending load. The results indicated that beams laminated using salvaged plywood tenons have significantly lower end slips. The composite effect was more than two times higher compared to the conventional Oak dowels, resulting in about 40% higher bending stiffness. Thus, the use of salvaged plywood tenons could be an alternative option to improve the bending stiffness and sustainability of DLT beams.