EXPERIMENTAL INVESTIGATION ON THE FRACTURE BEHAVIOUR OF STEEL FIBER REINFORCED CONCRETE (original) (raw)

Concrete is a composite material used for construction worldwide. The presence of cracks and pores inside concrete material is inevitable and it is necessary to investigate if they are stable or not. Hence problems related to fracture are vital in concrete. Fracture study assesses the ductile behavior of concrete structures under loading using various fracture parameters. Plain concrete possesses a very low tensile strength, limited ductility and little resistance to cracking. Addition of closely spaced and uniformly dispersed fibers to concrete acts as crack arrestor and substantially improves its static and dynamic properties. As a result of this ability to arrest cracks, fiber composites possess increased extensibility and tensile strength, both at first crack and at ultimate, particular under flexural loading; and the fibers are able to hold the matrix together even after extensive cracking. The present study aims at finding out how far the ductility of concrete can be improved by the addition of steel fibers in terms of fracture parameters by varying the fiber content. The fiber content was varied from 0% to 1.2% with an increment of 0.2%. The mechanical properties such as cube compressive strength, flexural strength, split tensile strength and modulus of elasticity were studied. From that results the optimum percentage of fiber was decided. Three-point bending test on notched beams (fracture tests) were conducted for determination of fracture parameters. The tests were done as per the guidelines of International Union of Laboratories and Experts in Construction Materials, Systems and Structures(RILEM)