Timber/Glass Adhesive Bonds for Structural Applications

Abstract: Timber with its natural appearance and glass with its transparency may be appealing material for architects and users of modern buildings. Glass is a brittle material, but it is about six times stiffer than timber. Combined appropriately, the materials could form different types of composite products, e.g. beams or shear walls, that can be included in the load-carrying structure of buildings. e knowledge on load- carrying timber/glass components is limited. e intention of this research has been to contribute to the knowledge required for the industry to be willing to produce timber/glass components for the market.The thesis includes experimental testing accompanied with complementary nite element simulations, which provide more details and information about the test results. Tests were performed on small-scale specimens with a bond area of 800 mm2 as well as on I-beam and shear wall prototypes. For the small-scale specimens tested in standard climate, three different adhesives were used for the bond line between timber and glass. ese specimens were tested in both tension and shear. In addition, one of the adhesives was used for small-scale shear specimens which were exposed to different humidity levels before the tests were performed. e 4 m long I-beam prototypes designed with a web of glass and wooden anges were tested in four- point bending. e shear wall prototypes were tested by applying either a vertical load, a horizontal load or a combination of these, all being applied in the plane of the shear wall.Of the three adhesives used in the small-scale testing, an acrylate adhesive had the largest strength, both in tension and in shear. e study on the effect of humidity was performed with this adhesive. is study indicates that the adhesive properties do not change dramatically in indoor climate. is adhesive was also used for twelve of the fourteen tested I-beams. e results from the beams show that a signi cant redundancy is obtained; the load at the nal failure was around 240 % of the load when the rst crack in the glass web appeared. e shear walls were glued using the acrylate adhesive and for a few cases a 2-component silicone based adhesive. e results from the shear wall tests showed the shear wall to behave in a much more brittle manner, without any noticeable redundancy.