Pull-out Behaviour of Axially Loaded Screwed-in Threaded Rods Embedded in CLT Elements: Experimental Study

Abstract

Experimental investigation on the pull-out behaviour, including the withdrawal capacity, slip stiffness and interfacial shear stress, of axially loaded screwed-in threaded rod embedded in cross laminated timber (CLT) was conducted. Specimens with varying embedment length and different number of threaded rods were tested in this study. To prevent premature splitting failure of timber, some specimens were reinforced in the direction perpendicular to the timber grain with self-tapping screws. Test results showed that the screwed-in threaded rod connections exhibited good pull-out behaviour with high withdrawal capacity and slip stiffness. Within a certain range, the withdrawal capacity increases considerably with the increase of embedment length, while the average interfacial shear stress shows the opposite tendency. The self-tapping screws played an important role on reducing the splitting of the timber and improving the withdrawal capacity and slip stiffness of the screwed-in threaded rod. Additionally, for the specimens with self-tapping screw reinforcements, the improvement of withdrawal capacity and stiffness when increasing the number of threaded rods are much more obvious than that of the specimens without the self-tapping screws, due to the change of failure modes.

Experimental static and seismic behaviour of glulam beam-to-column connection with screwed-in threaded rod joints

“…To match the torque wrench and nut, the screwed-in part at the extended end of the rods was processed into a square head, followed by a bolted thread part, as shown in Fig. 2 (Yang et al 2021). To reduce or prevent the splitting failure of the glulam beam end, three rows of 6 selftapping screws (VGZ7180) at the top surface and two rows of 4 self-tapping screws (VGZ7100) at side surface were screwed into the glulam beams perpendicular to the grain, as illustrated in Fig.…”

“…Considerable research on the withdrawal behaviour of screwed-in threaded rod joints has been conducted. There have been experimental, numerical, and theoretical investigations of withdrawal capacity and stiffness of threaded rods screwed-in glulam timber (Stamatopoulos and Malo 2015;Stamatopoulos and Malo 2016;Stamatopoulos and Malo 2018;Stamatopoulos and Malo 2020;Yang et al 2021). A model based on non-linear fracture mechanics has been used to estimate the withdrawal capacity of screws embedded in glulam (Jensen et al 2012).…”

Understanding the Impacts of Plant Capacities and Uncertainties on the Techno-Economic Analysis of Cross-Laminated Timber Production in the Southern U.S.

“…Recently, cross-laminated timber (CLT) has attracted increasing attention for mid-rise buildings as an environmentally sustainable alternative to reinforced concrete and steel [3][4][5][6]. CLT is a prefabricated mass timber product with odd lumber (sawn lumber or structural composite lumber) layers (typically 3, 5, or 7) stacked crosswise (typically 90°) to form a solid panel [1,[7][8][9][10]. The typical dimension of CLT panels can reach 0.30-3.05 meters in width, 0.10-0.25 meters in thickness, and up to 18 meters [11,12].…”