Concrete is the most used material for the construction in the modern time of infrastructures. Concrete is strong in compression but it is weak in tension and shear. To minimise those problems, fibres were introduced in concrete to enhance
its tensile strength and shear strength. In my present investigation, the mechanical properties of fibres reinforced concrete are studied by using steel fibre, glass fibre and polyamide fibre with a different weight fraction of fibres with respect to
cement. The mix design of M25 concrete with W/C ratio of 0.42 is prepared and total thirteen mixes included one control mix was prepared and tested in the laboratory. The total quantity of fibres mixed in the concrete are in order of 0%, 0.75%, 1.5%,
and 2.25% by weight of cement and one mix contains 0.33% of glass fibre, 0.33% of steel fibre and 0.33% of polyamide. The study shows that the mixed fibres provide better properties in controlling cracks and high strengths than single fibre and
concrete without fibre. On increasing the percentage of fibres beyond 1.5%, the strength of the concrete matrix decrease due to mat form of fibres or non-uniform distribution of fibres and also decrease due to non-cohesiveness of the concrete
particle to each other.
