Experimental Investigation of the Strength Properties of Corn Cob Ash Blended with Metakaolin Geopolymer Concrete.

Abstract

The concrete industry has a considerable impact on the environment especially in cement production. The negative environmental impact and high cost of cement are reasons for research efforts into discovering alternatives to concrete that are environmentally friendly such as geo-polymer concrete. Also, in an attempt to reduce the accumulation of waste in the environment corn cob ash was introduced in the metakaolin-based geopolymer. This research investigates the strength properties of corn cob ash blended metakaolin geopolymer concrete. Cube mold of size 100 mm x 100 mm x 100 mm and cylinder mold of size 200mm x 100mm were used to cast concrete samples containing 0, 10, 20, 30, and 40 % CCA. GPC was produced and cured at a temperature of 60^oC in the oven for 24 hours, after which they were cooled at room temperature in the laboratory and their properties were evaluated after 7, 14, 28, and 56 days of curing periods. The average compressive strength obtained at 28 days with 0, 10, 20, 30, and 40 % CCA is 28.4N/mm², 28.6N/mm², 28.4N/mm², 27.9/mm², 27.40N/mm² respectively. Concrete produced with 10%CCA has high compressive strength as compared to the control concrete. Concrete produced with 20%CCA has high splitting strength as compared to the control concrete. This study concluded that hardened GPC specimens with various replacements of CCA show comparable strength to that of the control specimens. This research recommends that metakaolin-based geo-polymer concrete containing CCA of 40 % CCA will lead to strong and durable concrete and could be used for structural concrete.