EFFECT OF STEEL FIBERS ON GFRP WRAPPED CONCRETE BEAMS by Bikramjit Singh
The fiber demand has been increased in civil engineering applications to enhance the properties of concrete. The cost effective technique is needed with this new material which improves the structural properties. The tensile reinforcement can be replaced fully or partially by using steel fibers. From earlier studies, it has been established that steel fiber improves the compressive as well as tensile strength of the concrete. There is an innovative idea to improve the strength and ductility of the concrete by using steel fibers with different proportions along with the Glass Fiber Reinforced Polymer Fabric as an external reinforcement. Because steel fibers provide inherent tensile strength to the concrete and GFRP fabric also improves the ductility of the concrete and reduces the corrosion of the member. So this combination of steel fibers and GFRP fabric is a great deal to enhance the post cracking strength of the concrete. So this experimental study is used to compare the flexural strength and ductility of the concrete beams and SFRC beams strengthened with GFRP fabric. The tests were conducted by using length of 60mm of fibers, aspect ratio 80 and volume fraction 0.5%, 1%, 1.5% and 2% by varying steel fiber content. The compression test was conducted on cubes and flexural test on prismatic beams. Then comparison between ductility of conventional concrete beams and SFRC beams and beams wrapped with GFRP Lamina was done. It was found that the load carrying capacity
increased as the fiber content increases from 0.5% to 1.5% and then decreases at 2%. Remarkable rise is noted in flexural strength with an increase in fiber content up to 1.5%. The flexural strength of SFRC 1.5% beams was increased by 102.5% than control beam and 44.93% than SFRC 1.5% beam without wrapping. The compressive strength of SFRC 1.5% cubes is increased by 20.25% than control cubes. The deflection ductility increases at 1.5% fiber volume fraction in both SFRC beams without wrapping and SFRC beams wrapped with GFRP lamina.