Influence of Recycled Aggregate on Shear Behavior of Steel Fibrous SCC

Abstract

Of all the different kinds of failures in concrete, shear failure is a sudden and brittle and occurs abruptly without any prior warning. To avoid these types of failures in concrete, beams are traditionally reinforced with stirrups at closer spacing based on design. An experimental study was carried out to study the shear behavior of steel fiber reinforced self-compacting concrete (SCC) beams with recycled concrete aggregate (RCA) as a complete replacement of both natural coarse and fine aggregate. The experimental program consists of 24 beams of which 12 beams were cast with natural aggregate and remaining 12 beams were cast using recycled aggregates as a complete replacement of natural aggregates. Due to the use of recycled concrete aggregates as coarse and fine aggregates, the compressive strength reduced by 7.8% and 8% for 30 and 70 MPa Concrete. The ultimate shear strength reduced by 14% and 12% due to use of recycled concrete aggregates for SCC30 and SCC70 beams respectively. The investigation indicates that the ultimate load and ultimate shear strength decreases as the spacing of stirrups increased. It was observed from the experimental results that addition of steel fibers enhanced the mechanical properties of both natural aggregate based self-compacting concrete (NASCC) and recycled aggregate based self-compacting concrete (RASCC). Also due to the addition of steel fibers the performance of SCC beams has improved. The shear strength obtained experimentally was compared with the existing models in the literature and the correlation was found to be satisfactory

Keywords

• Self-Compacting Concrete (SCC), Recycled concrete aggregate (RCA), steel fibers, ultimate shear strength.