A method for glue bond quality testing of flange_web adhesive connections of wooden I-beams (NT TR 552)

Abstract

  A test method for assessing the quality of glue bonds in the web-flange joint of I-beams has been developed. The method is based on a shear test of small pieces cut from the beam. The investigation has included shear tests on different specimen sizes, including the influence of the wood density, the wood moisture content and the influence of different pre-treatments (boiling) in order to detect possible gluing errors. A limited finite element analysis was also performed. The main conclusion is that pretreatment of the specimen by boiling is necessary in order to detect gluing errors. Another confirmation is that the wood failure percentage can be used as a good indicator of the bond quality. Finally, a draft test method for a possible standard is given.