The Behavior of Reinforced Concrete Beams Added Cold-Formed-Steel as Shear Reinforcement

Abstract

This paper presents an experimental study of concrete beams with cold-formedsteeladded as shear reinforcement. Cold-formed steel (CFS), also called light gauge steel or metal studs, is cold-formed into “C” or “Z” shaped members, capable of holding heavy loads. “Cold-Formed” means the sections are shaped at room temperature by guiding the steel through a series of rollers. Previous researchers have shown that CFSgenerally has a yield stress of 350 MPa to 550 MPa, but its use is mostly focused on anticipating beam bending. The purpose ofthis study was to determine the behavior of concrete beams with CFS added as a stirrup to increase the shear capacity of the beam. Two beams have been made with a size of 150x250x860 mm using the same 6D10 flexural reinforcement. One as a control beam (SB-C) using steel bar stirrups ∅5-200mm, the other as a beam added to CFS as stirrup reinforcement (SB-CFS) with a CFS cross section 20 mm wide, 0.75 thick mm and 120 mm CFS stirrup spacing. The test is carried out by applying a one-point loadingin the middle of the span of the beam so that the a/d ratio is 1.36. The parameters to be recorded are the capacity of the beam, the deflection that occurs, and the stiffness of the beam. The test data have been compared with the theoretical analysis results using the numerical software Response-2000. The resultshave shown that the increase in the shear capacity of the beam with the addition of CFS is 12.7% even though,according to Response-2000 analysis,it is 38.7%. The failure that occurs is shear failure according to the predetermined a/d ratio.