Effect of Metakaolin on the Strength Properties of Sisal Fibre Reinforced Concrete

Abstract

This paper presents the results of the investigation into the effect of metakaolin on the strength properties of sisal fibre reinforced concrete. Plain control concrete and binary concrete mixes (containing 5, 10, 15, 20, 25 and 30% metakaolin by weight of cement) were produced and cured for 7, 14, 28, 60 and 90 days respectively. A total of one hundred and five (105) cubes and beams were cast and tested for compressive strength, flexural strength as well as the density. The results showed that generally strengths decrease with increase in metakaolin content and increase with prolong curing period. The results also showed that, the density of the concrete decreases with increase in metakaolin content. Concrete cubes made with (5-10)% metakaolin and cured for beyond 28 days, achieved the 28 days target strength of 20 N/mm2. The optimum replacement level was observed at MK-10% cured for beyond 28 days. The data obtained were subjected to regression analysis and analysis of variance (ANOVA) in the MINITAB 16 statistical software. Models were developed to predict compressive strength, flexural strength and concrete density with curing period and metakaolin content as predictors at 5% level of significance, the result showed that, there is no significant difference between the predicted and the experimental values. The result of the regression analysis for compressive strength, flexural strength and density test indicated metakaolin and curing age are good predictors in the models developed.