Flexural Behavior of Modular Lightweight Composite Floor System

The floor system is a crucial element within modular buildings, bearing and distributing loads within the overall structure. Its flexural performance is of particular importance in ensuring the stability and safety of the entire system. In this paper, a lightweight composite floor system (LCFS) with significant advantages in transportation, assembly and disassembly is proposed. To investigate the mechanical properties of the proposed system, bending tests were performed on this composite floor. The test results demonstrate that the LCFS can be assembled expediently with the use of self-tapping screws and bolts, and it exhibits remarkable flexural properties. The failure pattern of the LCFS is characterized mainly by buckling failure in the compression zone of the upper flange of the long-side main beam (LMB) under bending. The effects of the wall thickness of the LMB and the short-side secondary beam (SSB), the height of the thin-walled steel beam, the section thickness of fiber-cement boards (FCBs), the strength of steel, and the screw spacing on the flexural behavior of LCFS were studied using an Abaqus finite-element model (FEM). A simplified method is proposed for the assessment of the ultimate moment capacity of a LCFS. The results of this study provide a reliable design basis and reference for the application of the container building LCFS in engineering practice.