Experimental comparison of selected pozzolanic materials

Abstract

Different pozzolanic materials are commonly used in concrete production with different properties. This paper compared the performance of metakaoline (MTK), bamboo leaf ash (BLA), pulverized fly ash (PFA) and corn cob ash (CCA), when used as partial replacement for cement in concrete. The replacement levels considered were 5, 10 and 15%. A concrete mix of ratio 1:2:4 was batched by weight using a water-cement ratio of 0.6. Cubes of size 150 mm were cast from the concrete and cured in water for 7, 14, 21 and 28 days. Compressive strength and workability tests were conducted, following standard procedures. The results indicated that all the materials had compressive strength comparable to that of the normal concrete (23.97 N/mm2), with strength activity indices that ranged from 80–90%. This performance was observed at maximum replacement levels of 5% for CCA and 10% for each of BLA and MTK, while up to 15% replacement level was used in the case of PFA. The paper concludes that the materials had different influences on the strength properties of concrete.