Experimental and Theoretical Studies on the Shear Resistance of Steel–Concrete–Steel Composite Structures with Bidirectional Steel Webs

Abstract

The steel–concrete–steel (SCS) sandwich composite structures with orthogonal longitudinal and transverse (bidirectional) steel webs exhibit superiorities in strength, ductility, impact resistance, blast resistance, and construction efficiency compared with the traditional engineering structures, offering a competitive alternative for applications such as submarine tunnels, nuclear shells, protective structures, offshore structures, etc. While there were several practices in engineering, the current design method is an application of the concrete code and there are few experiments that could support the design theory especially for the shear resistance. Unlike RC beams or steel beams, the SCS composite structures with bidirectional steel webs have multiple shear force transferring mechanisms, and it is of importance to investigate the contributions of the different mechanisms and how they work together as a composite structure. To address this problem, 16 shear tests of SCS composite structures with bidirectional steel webs were carried out and theoretical analysis was conducted. The shear resistance is categorized into three mechanisms: the composite truss, the pure shear of the axial web, and the dowel action of the flange. Then the theoretical method to predict the shear resistance considering the coworking of different mechanisms is proposed and compared with existing methods. It is proved that the proposed method reveals the antishear mechanism and is of satisfactory accuracy.