Glued-in rods (GiR) are an effective way to connect timber elements from both load bearing capacity/stiffness and aesthetic point of view. This method is also widely accepted as a method for reinforcement of the new and existing timber structures. Although GiR are widely used in timber structures, there is still no unified European test standards, product standards or design equations for such connections. At present, there are several test methods and procedures applied in research and development. In this paper two different methods for obtaining pull-out strength are presented. Furthermore, experimental investigation was conducted and results obtained from both methods are mutually compared. Pull – compression test procedure is the most common setup for experimental investigation, however this setup is sometimes not representative and it is often characterized as unreliable because it does not quite good correspond to practical applications. The second examined test procedure was pull-pull. Within the experimental investigation, total number of 36 specimens were tested and results obtained from both methods are shown, discussed and compared in this paper.
This paper describes the test program of glued-in deformed bar timber joint conducted in pull-pull configuration, which aims to investigate the bond behavior of glued-in deformed bar systems in glulam. The varying parameter are bar slenderness ratio and glue-line thickness. In order to obtain the bond stress distribution along the anchorage length, special deformed bar with strain gauges attached internally were designed. Test results show that both the bar slenderness ratio and glue-line thickness have obvious influence on withdrawal strength and bond behavior of glued-in deformed bar joint. Failure modes of specimens are also analyzed in this paper. Ductile failure modes of glued-in rod timber joint could be realized with reasonable design.
This paper explores the possibility of using flexible adhesives to dissipate energy in CLT buildings during earthquakes. In the first series of tests, a rod glued in a CLT panel with flexible adhesive was investigated. The connection was tested in pull-pull configuration using cyclic, tension-only loading. Different rod diameters and different thicknesses of the glue layer were tested. The tests have shown that the adhesive can resist large deformations and exhibits fairly large energy dissipation capacity. Based on the test results the numerical analyses were performed to test the behaviour of the connection when applied in CLT buildings. Existing constitutive models available in OpenSees software were used to simulate the specific hysteretic behaviour of the connection. The results have shown that the CLT wall anchored with "flexible" glued-in rods would have a significant energy dissipation capacity if a sufficient number of them were used as the hold-down devices. Such system could be used to dissipate energy in seismic areas.