Estimation of Shear Strength of High Strength Hybrid Fiber Reinforced Concrete

Concrete is one of the principle material for structures and it is widely used all over the world. While advanced technologies of concrete have been recently focused especially on developing high performance concrete which possesses high compressive strength and durability, such concrete shows extremely brittle failure. To improve such a poor property, Fiber reinforced cementitious composites (FRCC) have been developed. The usual way to solve the problem is the application of steel reinforcement in concrete. Other possibility is the application of different types of fibres in the concrete. The compressive, tensile and shear properties of fiber reinforced concrete (FRC) depended mostly on the type, content and selected FRC system. Fibres are added to the concrete merely not to increase the tensile strength itself but mainly to control the cracking, and to change the behaviour of cracked material by bridging of fibres across the cracks. Reinforcement of concrete with a single type of fiber may improve the desired properties to a limited level. A composite is termed as hybrid, if two or more types of fibers are rationally combined to produce a composite that derives benefits from each of the individual fibers and exhibits a synergetic response. Steel fibres are believed to contribute more to strength while polymeric fibres are believed to contribute to the ductility (i.e., toughness). In the case of hybrid systems (Hy- FRC), the review of literature concluded that the behaviour of Hy-FRC was, in fact, the combined behaviour of steel and polymeric fibres are more balanced in terms of strength and post-peak ductility.