Hybrid composite glulam timber reinforced using deformed steel bars and epoxy resin adhesive (RGTSB), was significantly developed in Kagoshima University. In this paper, a beam-to-beam connection for RGTSB and experimental data on the connection are presented...
Hybrid composite glulam timber reinforced using deformed steel bars and epoxy resin adhesive (RGTSB), was significantly developed in Kagoshima University. A long term laboratory investigation on a 4.5-meter-span hybrid timber beam and a non-hybrid timber beam was started from August 2011. The beam was made of RGTSB and another was of conventional glulam timber...
In this paper, bending behaviours in hybrid composite glulam timbers reinforced using deformed steel bars and epoxy resin adhesives (RGTSB) are presented. The technique RGTSB was developed in order to improve flexural stiffness and strength in glulam timbers...
The research study focuses on different strengthening techniques for timber concrete composites (TCC) using different types of wire and wire mesh integrated with a layer of epoxy on a timber core embedded in concrete using experimental and analytical procedure. The impact of TCC on axial compression performance, modulus of elasticity, failure mode and post failure behavior and ductility were compared to reference concrete specimens. Different types of wire and wire mesh used in strengthening of the timber core, timber core size and reinforcement in the concrete cylinder were all parameters considered in this study. Timing of application of the epoxy on the wire strengthened timber core was very important. For structural applications, where the weight reduction and ductility as well as post failure endurance are essential, the development of this composite is recommended. The ratio of the ductility index to the weight is discussed. The light weight of the timber composite, and the increased ductility were noted in this study. An equation to estimate the axial compression capacity of the strengthened timber concrete composite was developed in this study. This study will pave the way for further applications for timber concrete composite aiming at reducing dead weight of concrete and the reducing the amount of concrete and steel in construction.
This paper examines a new and very promising concept for prefabricated timber-concrete-composite floors (TCC-floors), were the heavy normal weight concrete is replaced by a lightweight concrete (LC) with a density of about 17 kN/m³. Investigations into the connections between lightweight concrete and timber indicate that the...
This paper presents an experimental evaluation of the fire resistance of glued-in rod timber joints using epoxy resin, with and without modification. A heat-resistant modified resin was designed by adding inorganic additives into the epoxy resin, aiming to improve the heat resistance. Joints that were made using the modified epoxy resin at room temperature showed a bearing capacity comparable to those with commercial epoxy resin. Twenty-one joint specimens with the modified epoxy resin and six with a commercial epoxy resin were tested in a fire furnace to evaluate the fire resistance. The main failure mode was the pull-out of the rod, which is typical in fire tests of this type of joints. As to the effects of the test parameters, this study considered the effects of adhesive types, sectional sizes, stress levels, and fireproof coatings. The test results showed that the fire resistance period of a joint can be evidently improved by modifying the resin and using the fireproof coating, as the improvements reached 73% and 35%, respectively, compared with the joint specimens with commercial epoxy resin. It was also found that, for all specimens, the fire resistance period decreased with an increase in the stress level and increased with an increase in the sectional sizes.
This project was conducted to quantify the performance of adhesives bond lines under
shear load subject to elevated temperature. The results add to the understanding of the
performance of polyurethane adhesive bond lines under elevated temperatures to address
areas of fire safety concern under the current building codes.
The project focused on studying the shear bond capacity of three wood species by using 3
types of adhesives with/without nanoclay treatment at 4 temperature levels. The three
wood species are Douglas-Fir, Hemlock and SPF. The adhesives are polyurethane (PU),
Phenol-Resorcinol-Formaldehyde (PRF) and Epoxy. PU and PRF specimens were also
tested with nanoclay treatment and without nanoclay treatment. Epoxy specimens were
tested without nanoclay treatment only. The temperature levels considered were room
temperature (about 20 °C), 60°C, 80°C and 100°C. The results indicate that the influence
of elevated temperature on the shear bond strength of PU and PRF adhesive was in the
range of 20 to 30% regardless of nanoclay treatment. Regardless of species, PU or PRF,
with or without nanoclay, the average shear strength for 100°C oven temperature
treatment ranged from 6.0 to 7.5 MPa. In the case of SPF PU specimens treatment with
nanoclay reduced the variability of shear strength significantly from 12% at room
temperature to 5% after 100°C oven treatment. This is an important aspect that needs
further verification for enhancement of performance. Finally the data in this study can be
used to support modeling of timber component subjected to elevated temperature.