Semi-rigid STC beam-to-column joints: review, future perspectives and needs

The combination ofsteel and timber in the form ofcomposite structures (STC) has emerged in the past decade, benefitingfrom the "new" performant engineered woodproducts (E WPS) and their environmentalfriendly character to reduce carbon footprint of the construction industry. Though STC solutions are promising and can be alreadyfound in the literature, the available know-how is yet limited, e. g. not expressed in design codes, and its use in actual projects scarce. Like in more traditional solutions, such as bare steel or steel-concrete composite, the joints at the extremities of the STC beam can play a key role in the structural response. In this paper, a review on the investigatedjoint solutions available in the literature is first provided, identijfi/ing the diflerent configurations, characterizing their mechanical behaviour and identifying the "common " failure mechanisms. After, in the perspective of the extension of the component method for the design of STC beam-to-column joints, the joint components are discussed with particular attention for those involving E WPs in the load transfer mechanics not yet covered by the normative documents,. Then, based on the identified gaps and on the challenges of a construction sector requiring the transition to a circular economy, the future perspectives and needs are exposed.