Mechanical properties of high strength concrete using fly ash

Recently, a number of researches have involved improving the concrete technology requirements through advanced research. These studies involved high strength concrete HSC, were highly dependent on the quality of ingredient- materials. HSC production potentially involves several trial mixes and uses high quantities of fine materials thus making it very costly and time consuming. The objectives of this study were to reduce the production cost, time required and to improve HSC properties by providing control mixes and using fly ash as partial cement replacement. This was done by experimentally investigating the HSC production using 10%, 20% and 30% replacement of cement by fly ash and selecting the optimum replacement content. All concrete mixes were homogeneous in fresh concrete state, did not show any sign of segregation and maintains slump between 80-110mm. Fly ash addition further improved the workability. At the age 90 days, all concrete mixes achieved the cube compressive strength between 72 to 120MPa. Tensile and flexural strength were increased using fly ash using fly ash. Higher strength concrete showed low ductility because the ultimate strain was found less than 0.35%, there was In general 20% fly ash content was found the optimum.