Experimental Evaluation Shear Strength of Steel Fibre Reinforced Concrete Deep Beam

Abstract

The application of fibers to R.C.C. structural members would be one of the major areas of use in structural engineering. The fibers to R.C.C. have got an existing future in construction in days ahead. The objective of the present experimental investigation was to evaluate ultimate shear strength of Steel Fiber Reinforced Concrete deep beams without shear reinforcement. The purpose of this project is to present the results of investigations where the Steel Fiber contribute in the shear strength of the deep beam or not. The object was also to understand the deflection and the cracking behavior of SFRC deep beam without stirrups. Test data investigates the behavior of concrete deep beams reinforced with conventional steel bars and steel fibers subjected to two point symmetrical loading. Variables in test data are effective span to effective depth ratio of deep beam (1, 1.5 & 2), aspect ratio of fiber (50 & 80), and volume fraction of fibers (0%, 1%, 1.5% & 2% of fibers for 50 aspect ratio fibers and 0%, 0.5%, 0.75% & 1% for 80 aspect ratio fibers).Twenty four concrete deep beams of dimensions 800x300x150mm (8 Nos.), 800x400x150mm (8 Nos.),and 800x600x150mm (8Nos) were tested to destruction of applying gradually increased load of which 12 numbers of beams were casted with hook end steel fibers of 50 aspect ratio and next 12 numbers of beams were casted with 80 aspect ratio steel fibers. The influence of fibers content in the concrete deep beams has been studied by measuring the deflection of deep beams below point loads and the shear strength of concrete. Load deflection response, crack patterns, and modes of failures for SFRC deep beams are studied experimentally. In result we have found that after replacing all shear reinforcement in deep beam by increasing the percentage of steel fibers ultimate shear strength increases and there is significant influence in mode of failures of beam. Index Terms-Steel Fiber reinforced concrete, deep beam, ultimate shear strength, deflection, crack patterns, modes of failures.