Experimental investigations of glued-in rod connections in CLT

The widespread availability of cross-laminated timber (CLT) provides opportunities to extend the use of wood structures beyond low-rise residential construction. Glued-in rods (GiR) are an interesting technical solution for numerous timber structural applications, amongst them, the not yet exploited potential in conjunction with CLT. This paper summarises experimental investigation on the performance of GiR in CLT. Two 5-ply CLT panel thicknesses (139 and 175 mm), two steel rod diameters (dR = 12.7 and 19.1 mm), and five anchorage lengths (la= 6dR, 10dR, 12dR, 14dR and 18dR) were considered in applications parallel and perpendicular to the CLT major strength axis. A total of 220 uni-axial quasi-static monotonic tension tests were conducted. The results, assessed in terms of load-carrying capacity (ranging from 14 kN to 154 kN) and failure modes (plug-shear failure and lamination tear-out), demonstrated the impact of the connection's geometric design parameters and that steel rods glued into CLT offer an alternative high capacity connection. The results will serve as the benchmark for subsequent numerical modelling, including the determination of joint capacity.