Development of Beam to Beam Connectors Made of Densified Veneer Wood

In an ongoing research project at KIT Timber Structures and Building Construction an innovative beam to beam connector made of densified veneer wood (DVW) is developed. In a first part of the project different surface modifications were examined aiming at an increased friction between connector and timber member. The modifications included sanding and sandblasting, coating with mineral particles using different bonding agents as well as milling with different milling tools. The static coefficient of friction between the modified densified veneer wood and softwood was determined in tests. Mean friction coefficients greater than 1.0 and characteristic values of up to 0.9 were found. This means a significant increase compared to the value of 0.25 given in Eurocode 5 taking the rope effect into account. In a second part the behaviour of the modified surfaces combined with inclined screws was examined. The positive influence of the surface modification was confirmed. An increase in load-bearing capacity of up to 40% was established. Lastly, a first prototype of a beam to beam connector was manufactured and tested. The results are now used for an improved second prototype.