Tensile strength of Glulam connection with glued-in threaded steel rod

Abstract

One possible way to make a connection in wood tensile member is by using glued-in threaded steel rod. The main objective in using this type of connection is to obtain a relatively high ductility. Another advantage of using such connection type is that no additional connecting wood elements are needed. In this study, tensile tests were conducted on glulam connections with glued-in rods. Each glulam specimen has a cross section of 200 mm x 300 mm and consists of 12 laminae each of which is 50 mm x 100 mm. The length of each specimen is 450 mm. The nominal diameter of threaded-glued-in rod in each specimen is 8 mm. The embedment length of the rod is 150 mm. Two third of the embedment length is glued and the rest is not glued. To study the effect of various specific gravity on the connection strength, three wood species were used in this study, namely albizia, jelutong, and camphor. There are three specimens for each species. Failure mode occurred after the tests was either shear failure in the boundary of the rod and glulam or rod yielding. From the load deflection curves of the connections, it can be concluded that connections made from albizia failed in brittle manner. and connections made from jelutong and camphor failed in ductile manner with the average ductility ratios of 1.57 and 1.67, respectively. As expected, the ultimate strength of connection made from wood with higher specific gravity was higher than those made from wood with lower specific gravity.