A post tensioned timber connection made of glulam has been developed at the ETH in Zurich. The connection is made of spruce with ash reinforcement in the connection area where high stresses perpendicular to the grain occur. The moment-rotation-behaviour of this post-tensioned beam-column timber joint has been analysed with a series of static bending tests. The timber joint was loaded at the ends of the beams in order to apply a moment to the connection. The tests were conducted with different forces in the tendon, from 300 kN up to 700 kN. The bending tests were performed with a controlled load level, so that no embedment failure perpendicular to the grain occurred in the column. The intended self-centring behaviour could be verified and no damage could be observed during all the tests.
A final bending test was conducted in order to study the failure mode of the post-tensioned timber connection. The vertical load on the beams was increased until the tendon-elongation got so high that the test had to be aborted due to safety reasons. Nearly no damage occurred during the last test, only minor residual deformations could be observed. The failure is an embedment failure in the column due to exceedance of the strength perpendicular to the grain. The specimen, test setup, instrumentation and the results of all performed tests are presented in this technical report.
