TRIPLE BLENDING EFFECT OF FLY ASH, SILICA FUME AND STEEL FIBERS ON MECHANICAL BEHAVIOUR OF HIGH STRENGTH CONCRETE

Compressive strength is an integral property of concrete that play a key role in the construction industry. The present works investigates the effect of triple blend of fly ash, silica fume and steel fibers on the compressive, split tensile and flexural strength of concrete. Fly ash (FA) and silica fume (SF) are introduced as a partial replacement for cement for various additions of steel fibers by volume of concrete. A replacement level of 0% FA with 0 %, 5%, 10%, 15% SF in place of cement for 0% addition of steel fibers by volume of concrete is used for the preparation of first set of samples. Second set of samples were prepared with the change in fly ash proportion to 20%, keeping replacement levels of SF unchanged for 0% inclusion of steel fibers and the last set of samples were prepared with 40% FA replacement percentage without any change in the replacements of SF for the same 0% steel fibers. Likewise, the same combinations of FA and SF were repeated for 0.5% and 1% steel fibers and tested for various strength results after 28 days curing. Later, it is seen that an optimum mix of 20% FA with 10% SF for 1% inclusion of steel fibers, produced the maximum compressive strength of 81.20 N/mm2 and maximum flexural strength of 8.40 MPa.