Development of wooden block shear wall – Improvement of stiffness by utilizing elements of densified wood

Abstract The objective of this research was to study the performance of a wooden block shear wall which utilizes compressed wood as a connecting element in place of the traditional metal connectors. The compressed wood was made by compressing Japanese cedar (Cryptomeria japonica) to a compression ratio of 63% without fixation treatment. The connecting elements, namely diamond keys (DKs), recover their radial compressed dimension when absorbing moisture. The expansion of the wood causes a tighter fit of the wood blocks, thereby improving the system stiffness. DKs work as fuses by absorbing most of the stress and damage. This allows the structure to be readjusted and reused after earthquakes. The wooden blocks are made of glued-laminated timber based on European red pine (Pinus sylvestris). The behavior of the wall was studied by means of a finite element method (FEM) and full-scale shear tests. The material properties were found by performing mechanical tests, using digital image analysis, and strain gauges to measure the strain. The stiffness of the wall and how it is affected by the DKs are described. The FEM provided predictions which are in agreement with experimental results of wood block wall systems. The addition of DKs increased the stiffness by up to 2.5-fold. Future improvement of FEM will include accounting for the contribution of vertical connectors and out-of-plane forces.