Design guidelines of composite sections for concrete beams with profiled steel sheath encasement

Abstract

This investigation aims at establishing design guidelines for various limit states of concrete beams with profiled steel sheath encasement. This type is used when weldability is not suitable for thin sheets to form tubular sections. For concrete-filled profiled steel sheath (CFPS), three design criteria are considered in the proposed design guidelines: (1) ultimate limit state considering the imposed confinement of the profiled steel sheath encasement, (2) serviceability limit states for shored construction, and (3) sheath thickness to avoid local buckling. The partial shear connection allows for the design to depend on the bond’s physical appearance of the concrete–steel interface. Verification of the proposed design procedures is carried out against two sets of previous investigations. The first set is a well-documented experimental program and a finite element analysis of several configurations of seventeen profiled sections. The other is a comparison with the predictions of selective international codes and analytical formulas for commonly used concrete-filled steel tubes (CFST). The results indicated very good predictions of the proposed guidelines and the suitability to capture the salient features of behavior of both CFPS and CFST.