Experimental Investigation on Structural Behavior of Continuous Concrete Beams Curved in Plan Reinforced with Cold-Formed Steel C-Section

Abstract

This paper presents an experimental program on horizontally curved concrete beams reinforced with cold-formed steel C-section. Cold-formed steel sections are widely utilized in many construction fields as its low cost, light weight, eases manufacturing, reasonable force, erection and transportation. In some cases, increasing ultimate loading capacity with constant dimensions is needed for curved beams to resist high applied loads. Curved beams as compared to straight ones, are usually constructed with large width due to the high shear strength requirements. But in this study, transverse shear reinforcement with various configurations is introduced to improve a functional section with firm height and width for curved beams reinforced by cold-formed steel C-section. The experimental program is performed on curved in plan continuous concrete beam reinforced with a CFS C-section under two-point loading in which the ultimate loading strength, load-deflection curve, and crack width are studied by replacing the traditional steel bars by a CFS C-section with openings, and with varying configuration of transverse reinforcement. In this research, reinforcing curved beam by a CFS section and the configurations of transverse shear reinforcement are the main studied variables. Transverse shear reinforcement with different arrangement are utilized, such as zig-zag, horizontal, vertical and inclined cross-stirrups shear reinforcement. Eight concrete curved beams were cast and tested under combination of two-point and continuing loading conditions. Depending on configuration of the transverse reinforcement, the experimental test outcomes indicated that introducing CFS C-section and transverse shear reinforcement increases ultimate loading strength of reinforced concrete curved in plan beam, enhances the deflection response and restricts the crack width for the same loading level.