Effect of Pozzolanas on Fibre Reinforced Concrete

Abstract

India generates more than 88 million tons of fly ash annually, predominantly of Class F type, with a meager utilization rate of approximately 10 to 15%. To enhance its utilization, an extensive investigation was conducted to explore its incorporation in concrete. This article presents the outcomes of an experimental study involving concrete with elevated proportions of Class F fly ash. Portland cement was substituted with three different percentages (40%, 45%, and 50%) of Class F fly ash. Tests were conducted to assess fresh concrete properties, including slump, air content, unit weight, and temperature. Compressive, splitting tensile, and flexural strengths were measured over a 28-day testing period. The results indicated that incorporating high volumes of Class F fly ash as a partial replacement for cement led to a reduction in the 28-day compressive and flexural strengths of the concrete. Nevertheless, based on the findings, it was concluded that Class F fly ash can be effectively utilized up to a 50% level of cement replacement in concrete, particularly for precast elements and reinforced cement concrete construction.

Keywords: Class F fly ash, Fly ash utilization, High volume fly ash concrete.

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