The effect of high temperature on the mechanical properties of concrete reinforced by high strength steel fibers with various aspect ratios has been investigated in this detailed study. Now a days from industrial point of view a great attention has been given to the use of additive materials such as high strength steel fibers in concrete and cement products. On Investigations it has been revealed that the addition of high strength steel fibers into normal concrete impart significant improvement for controlling its surface cracking, along with increasing their tensile strength, durability and flexural strength. Considering the advantages of these additive materials, high strength concrete samples were resulted with different mix designs. The tests show that mixed use of steel fibers give excellent results in terms of improving mechanical strength , structural characteristics of the concrete material developed. In all samples, the surface cracking of concrete was decreased significantly by adding suitable fibers in terms of sort, diameter, and length. So that, these newly developed structural concrete have promising potentials for further research, development as well as an structurally important building block material.

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