Theorical and Experimental Studies on Hybrid Steel-RC Walls

Abstract

Hybrid RCS frames consisting of reinforced concrete (RC) column and steel (S) are used frequently in practice for mid- to high-rise buildings. RCS frames possess several advantages from structural, economical and construction view points compared to either traditional RC or steel frames. One of the key elements in RCS frames is the composite shear wall consisting of several steel sections encased in reinforced concrete. Regarding the RC walls reinforced by more than one steel profile, namely hybrid steel-RC wall, although a number of researchers have focused on its various aspects, they are currently not covered by standards because they are neither reinforced concrete structures in the sense of Eurocode 2 or ACI318, nor composite steel-concrete structures in the sense of Eurocode 4 or AISC 2010. This paper deals with theoretical and experimental study on hybrid walls with several embedded steel profiles. The first part of this paper is dedicated to present a tentative design model for hybrid elements (walls and columns) subjected to combined axial force, bending and shear. Particular attention will be paid to shear (longitudinal and transversal) resistances because preventing shear failure is one of the major concerns when designing a composite structural member. Next, an experimental study on the static behavior of hybrid walls subjected to combined shear and bending is presented. Six hybrid walls with different types of the structural steel-concrete connection and reinforcement detailing are tested. The specimens exhibited ductility behavior. The specimens with shear connectors (i.e. headed studs, stiffeners) were more ductile in terms of displacement ductility than the ones without connectors. Finally, to assess the validity of the developed design model a comparison between the experimental results and design predictions is presented.