Mechanical behaviour of multi-panel cross laminated timber shear-walls with stiff connectors

Multi-panel Cross Laminated Timber shear-walls with stiff vertical joints may represent a valuable structural solution for multi-storey timber buildings in low seismic prone areas. In this study, the opportunity of using shear-key connectors in the assemblage of stiff vertical joints as an alternative to short-spacing traditional dowel-type mechanical fasteners is evaluated. The mechanical behaviour of two types of stiff shear-key connectors is investigated through an experimental campaign conducted at joint and wall level. Shear tests were firstly carried out to determine the mechanical properties of panel-to-panel joints assembled with the shear-key connectors. The results are compared with those obtained from shear tests on joints with screwed connections (half-lap and spline joints). Full-scale shear-wall tests were then performed to determine the mechanical performances of the con-nectors at wall level. Joints with a single shear-key connector showed values of stiffness and strength comparable to those that would be obtained for vertical spline joints with approximately thirteen couples of 6 mm screws. The failure modes on the joints with shear-key connector were characterized by either a localized crushing in the wood or the shear failure in outer lamination of the CLT panels with no plastic deformation of the connectors.

Automated summary

This study evaluates the potential of using multi-panel cross laminated timber shear-walls with stiff vertical joints as a structural solution for multi-storey timber buildings in low seismic prone areas. The mechanical behavior of two types of shear-key connectors is investigated through experimental testing at joint and wall level. The results show that joints with a single shear-key connector exhibit stiffness and strength comparable to those with traditional screw connections.