ABSTRACT
Steel-concrete composite beams demonstrate extraordinary stability concerning lateral and lateral-torsional buckling, due to the restraint on the top flange. Recent structural research advancements reinforce this improvement, possibly leading to omitting or reducing the number of braces for girders. However, composite beams can still fail due to lateral or lateral-torsional buckling under negative bending, where the bottom flange is subjected to compressive force. Therefore, a proper understanding of the buckling behavior and capacity is necessary to promote the use of concrete slabs in buckling design. On the other hand, recent developments in rigid shear connectors, such as puzzle-shaped shear connectors, are attracting interest as a novel type of composite beam design. However, the contribution of puzzle-shaped shear connectors to lateral buckling strength remains unexplored. To further promote this latest system in earthquake-prone regions such as Japan, quantifying its strength enhancement and reliability is mandatory. Given this context, this paper reports recent experimental results on composite beams with puzzle-shaped shear connectors under asymmetric cyclic loading. The results confirm the significant performance of puzzle-shaped shear connectors in increasing the lateral buckling strength of beams.
