Behaviour of a Demountable Continuous Shear Connection in Steel‐Concrete Composite Beams

Abstract Abstract: A demountable continuous shear connection is proposed to improve the reusability of steel‐concrete composite beams and promote the development of a circular economy in construction. Unlike traditional welded shear studs and bolted shear connections, this continuous shear connection consists of a steel bar with discrete shear keys, thereby enhancing installation efficiency on sites. Both the concrete slab and steel beam can be simply reused after sliding the shear connection out of the steel beam. To study the interaction between these parts, elemental shear tests were firstly conducted. By studying steel plates of different thicknesses and grades, the expected connection shear fracture failure was observed. Subsequently, horizontal pushout tests were also implemented, by which the effects of the steel plate grade, thickness and the number of shear keys in a connection on the structural behaviour of composite beams were comprehensively explored. Results of tests indicated that the shear capacity of the connection was not significantly impaired as the number of shear keys increases. Because a large contact area was created between the embedded plate and surrounding concrete, premature concrete crushing observed in bolted shear connection cases was greatly improved. As a result, the application of the demountable continuous shear connection can significantly extend the service life of steel‐concrete composite beams, thereby providing huge potential for reuse.