Behavior of cross-laminated timber panels under different shear loading scenarios

There is limited knowledge of the behaviour of cross-laminated timber (CLT) panels in situations other than their use as slabs or walls. As a preliminary step toward implementing tests on structural-sized bending members, three types of tests were carried out on 60 cm thick, three-layer CLT panels to verify their behaviour under shear loading in different conditions. Also, numerical models were developed and relate to the observed failure modes. First, in-plane shear tests were performed. Second, pull-out shear tests were conducted on specimens composed of CLT and concrete with recycled aggregates. In these two tests, two orientations of the CLT face boards relative to the load direction were investigated: parallel and perpendicular. Finally, four bending tests were conducted on short CLT I-beams to evaluate the flexural shear strength of the CLT panels used as the web of the section. In the first two tests, the shear strength was found equivalent for parallel-oriented panels, with variations of up to 33 % in the case of perpendicular-oriented panels. Both orientations showed similar slip modulus values in the CLT-concrete pull-out shear tests. The glued flange-web joint of the beams did not show any noticeable failure or slippage, which would enable the design of cassette solutions with CLT ribs. The results of this research will serve as the basis for the design of various structural solutions, including timber-concrete composite (TCC) systems with casettte cross-section in which perforations made in the CLT panels act as shear connectors between the timber and the concrete. • Cross laminated timber panels tested under different shear load scenarios. • Shear strength depending on the load scenario and orientation of the layers. • Perforated timber panels allow rigid shear connection in timber-concrete composites. • Good shear performance of I-beams made of timber panels with glued web and flanges.