Disassembly and structural reuse potential of steel-timber shear connections with screws

Abstract

The paper evaluates the disassembly capability and reuse potential of steel-timber shear connections. Experiments involving double shear configurations with coach screws of three diameters are detailed. Monotonic tests were first performed for each configuration to evaluate the stiffness, strength, and ductility. Counterparts were then tested under ten loading-unloading cycles, to 40% of the capacity obtained from the monotonic tests, to evaluate stiffness degradation characteristics, screw deformations, and cross-laminated timber (CLT) panel damage. After disassembly and measurements, the specimens were reassembled and tested up to failure. The measurements indicated that the secant stiffness enhances after the first loading cycle and is then largely constant to the tenth cycle. After disassembly, the screws had permanent deformations, and the timber panels indicated limited damage during the cyclic loading. The reassembled specimens had similar stiffness, strength, ductility, and failure modes as the monotonic test specimens. Based on test measurements, both the steel profile and the CLT panels have full structural reusability. The test results can be used as a measure for quantification of the structural reuse potential through an index that can be incorporated into established building circularity indicators.