Quasi-static cyclic testing of low-damage post-tensioned beam-column connection with hybrid steel-timber configuration

Building up a safer, more resilient, and sustainable community is nowadays recognized as a priority objective. Towards this goal, there is an increasing interest in the construction sector in developing and implementing low-damage solutions based on eco-friendly materials. In this context, recent research has shown that implementing low-damage post-tensioned timber-based solutions - referred to as Pres-Lam (Prestressed-Laminated timber) technology - allows for enhanced seismic performance in the case of new structures and represents a promising solution for seismic retrofitting applications. Moreover, the high versatility of the post-tensioned “hybrid” connection concept has led to the investigation of alternative configurations based on mixed construction materials, e.g. timber-concrete or timber-steel solutions. In this context, and as part of some wider research projects, this paper presents and discusses the ongoing experimental campaign on a low-damage post-tensioned beam-column connec- tion, characterized by a timber beam and a steel column. More specifically, quasi-static cyclic tests are carried out on an 80% scaled specimen, considering alternative configurations by varying both the post-tensioning force and the dimensions of the external dissipaters. This investigation is deemed an extension of already available results from a past experimental campaign developed at Sapienza University of Rome in 2018. The experimental results are also compared with analytical and numerical analyses - based on a lumped-plasticity modelling approach - for validation and calibration purposes. The preliminary experimental results proved the high seismic performance of the solution, which can sustain severe displacement demand (up to 2.5% of inter-storey drift ratio) without substantial structural damage.