Effect of the Blend of Cement - Sorghum Waste Ash (Sorghum Vulgare) on the Flexural Strength Properties of Concrete

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Department of Civil Engineering, University of Ilorin, Ilorin, Nigeria


The continuous depletion of lime stone deposits during cement production is increasingly posing a challenge in the construction industry. Other disadvantage associated with cement production includes CO2 emission into the atmosphere and its negative effect on global warming. As a result, the research was geared towards at proffering alternatives to use of cement with impairing on the overall performance of concrete. Investigating the effect of Sorghum waste ash (SWA) - ordinary Portland cement blends on the flexural strength properties of concrete formed the bases for this study. Ordinary Portland cement was partially replaced with sorghum waste ash at an interval of 5, 10, 15 and 20 %. A water-cement ratio and mix ratio of 0.61 and 1:1.5:3.2 were adopted respectively. Chemical analysis test carried out on the ash sample was done in accordance with ASTM C618 (1999). Sorghum waste ash had silica content of 74 %, which was above the minimum of 50% specified in ASTM C618 (1999) for any material to be classified as a pozzolan. Twenty five beam specimens of size of 100 × 100 × 500 mm were cast and test for flexural strength after 28 days curing period. This was done in accordance with BS EN 12390-1(2000). Validation of experimental results was done using ANSYS 15.1 finite element software. A peak flexural strength of 6.079 N/mm2 was gotten at 10 % cement level with ash. The strength result of plain concrete was 7.304 N/mm2.



Sorghum waste grain,, Pozzolans,, Flexural strength, Concrete