High capacity glued-in rod connections in Cross-Laminated Timber (CLT) structures

Abstract

Glued-in rods are efficient and high-capacity connections for achieving high-strength connections in new timber structures and reinforcing existing timber buildings. With the emergence of cross-laminated timber (CLT) and the construction of high-rise buildings, there is a potential for glued-in rods to be adopted in CLT construction. This paper investigates the experimental performance of CLT connections with multiple glued-in rods. For this purpose, full-scale tests were conducted, where the specimens were tested in monotonic and cyclic loading by varying anchorage lengths of rods and rod to grain angle. The monotonic tests showed that glued-in rods embedded on the edge of the CLT at different angles and locations could provide high-strength connections for CLT. Rod to grain angle affected the failure mode and the force vs. displacement curve of the connections. Based on the shear strength of the bondline, a simple design equation is proposed to predict the pull-out strength of the glued-in rods embedded in CLT. A set of comparative investigation was also conducted to study the effect of the reinforcement using screws with the glued-in rod connections while tested in monotonic tension and compression. Moreover, the cyclic loadings illustrated that glued-in rod connections keep their elastic properties until failure. The outcomes of this research demonstrated that glued-in rod connections could offer a reliable and robust connection for CLT construction in seismic active regions.