Utdragshållfasthet hos limmade och olimmade gängstänger i limträ
This essay examines pull-out strength of threaded rods fixed into glulam timber. The technology is intended to be used in hidden joints between glulam components. The work began with a study of literature focusing on current research within the topic, mainly to create a base of knowledge before the testing was initiated. Studies of scientific articles reveals a lack of research within this area, which makes it difficult to develop standards and calculation models for these joints. The drill holes in the tests have a diameter of 7 mm. The pull-out tests include three depths of threading as well as three fiber directions. Threaded M8 rods pencilled with glue and without glue are tested, after which the results are compared with each other. Results are indicating a slightly inferior pull-out strength parallel to the grain compared to perpendicular dito. A linear relationship between the pull-out strength and geometry of the joint can be observed, only on rods perpendicular to the grain however. More testing is needed. Prior to the experiments, assumptions were made that most of the glue was scraped off when the rod was screwed in. This appears to be correct since some non glued rods under certain conditions even showed better performance than glued ones. Statistically reliable conclusions can not be made since the quantity oftests in this work is too small. Nevertheless, the results indicates that further testing also on non glued rods is essential.