Suitability of groundnut shell ash/lime mixture in production of concrete

Abstract

The suitability of groundnut shell ash (GSA) mixed with 45% slaked lime was investigated. The aim was to determine the percentage GSA/lime and water-cement ratio that would give the 28 – day minimum strength of 20N/mm2. Groundnut shells were burnt and the ash sieved using 150 micrometer sieve. The ash mixed with 45% slaked lime was used to partially replace ordinary Portland cement (OPC) in various proportions. The design mix used was 1:2:4 and water – cement ratios of 0.45, 0.55 and 0.65 by weight. Nine cubes of side 150mm were cast for each proportion and water – cement ratio. The cubes were cured by complete immersion in water at room temperature. Three cubes were tested for density and strength at each of the ages of 7, 14 and 28 days for each proportion of OPC/GSA – lime. It was concluded that for a mix of 1:2:4, the proportion of GSA/lime up to 20% gave the 28-day minimum strength of 20N/mm2 at water-cement ratio of 0.65 and was recommended for use as structural concrete.

Keywords: Groundnut shell ash, Cement, Concrete, Water-cement ratio, Strength

Nigerian Journal of Technological Research, vol 7(1) 2012