Effect of Micro Steel Fibre on Properties of Concrete

Abstract

Cement concrete is the most extensively used construction material in the world. The reason for its extensive use is that it provides good workability and can be moulded to any shape. Ordinary cement concrete possesses a very low tensile strength, limited ductility and little resistance to cracking. Internal micro cracks, leading to brittle failure of concrete. In this modern age, civil engineering constructions have their own structural and durability requirements, every structure has its own intended purpose and hence to meet this purpose, modification in traditional cement concrete has become mandatory. It has been found that different type of fibers added in specific percentage to concrete improves the mechanical properties, durability and serviceability of the structure. It is now established that one of the important properties of Steel Fiber Reinforced Concrete (SFRC) is its superior resistance to cracking and crack propagation. In this thesis effect of fibers on the strength of concrete for M30 and M40 grade have been studied by varying the percentage of fibers in concrete. Fiber content were varied by 0%, 0.50%, 1%, 1.5% and 2%. Cubes of size 150mmX150mmX150mm to check the compressive strength and beams of size 500mmX100mmX100mm for checking flexural strength and cylinder of size 150mmX200mm for checking the split tensile strength were casted. All the specimens were cured for the period of 7 and 28 days before crushing. The results of fiber reinforced concrete for 7days and 28days curing with varied percentage of fiber were studied and it has been found that there is significant strength improvement in steel fiber reinforced concrete. Also, it has been observed that with the increase in fiber content value increases the strength of concrete. Slump cone test was adopted to measure the workability of concrete. The Slump cone test results revealed that workability gets reduced with the increase in fiber content.