Experimental evaluation of a novel reversible steel-timber shear connection

Abstract

Driven by increasing environmental demands within the construction sector, steel-timber composite structures have gained considerable attention as sustainable load-bearing alternatives. Most existing solutions rely on dowel-type fasteners, which often induce premature timber damage during early loading stages, thereby limiting mechanical performance and disassembly and reuse potential. This study introduces a novel shear connection concept aimed at increasing the yield resistance of timber, thereby promoting disassembly and reuse by reducing damage during the loading phase. The experimental programme consisted of three distinct test series: (i) isolated local timber crushing tests to examine failure mechanisms and assess the performance of existing analytical formulations; (ii) push-out tests on two configurations of the proposed steel block connection; and (iii) push-out tests on conventional bolted connections for sake of comparison. The experimental results were subsequently reproduced using analytical formulations and detailed numerical models. Subsequently, a small parametric study was conducted to identify the critical components governing the connection response. The results demonstrate that the proposed steel block connection significantly improves yield resistance and elastic stiffness compared to conventional bolted systems. By enhancing the yield resistance and thereby delaying the onset of irreversible damage to higher load levels, the connection offers improved suitability for reuse and disassembly, which is fully aligned with contemporary circular construction objectives. The study also shows that, although Eurocode-based timber crushing models yield reasonable predictions for isolated crushing behaviour, more advanced formulations are required to capture the connection response with greater accuracy.