Effect of Ripe and Unripe Plantain Peel Ash on Concrete Workability and Compressive Strength

Plantain (Musa paradisiaca) peels are by-product of plantain fruits, constituting about 40% of the fruits. Performance effects of Ripe Plantain peel ash (RPPA) and Unripe Plantain peel ash (UPPA) in concrete were investigated in this research. Both RPPA and UPPA were added to the concrete as admixture in the proportion of 1.5% and 2.5%. The percentage composition of Silica (SiO2) and Alumina (Al2O3) contents in RPPA and UPPA were determined using spectrometry method of analysis. Slump test on the fresh concrete and compressive strength test were carried out on the concrete cube for 7, 14, 28, 56 and 90 days. The Silica (SiO2) content for RPPA and UPPA were 46.37% and 54.00% respectively while the Alumina (Al2O3) content for RPPA and UPPA were 2.20% and 3.08% respectively. The compressive strength for the control mix at 28-day is 20.4N/mm2, while that of 1.5 and 2.5% RPPP are 16.3 and 14.0N/mm2 respectively representing decrease of 20.15 and 31.58% respectively, compressive strength results for concrete containing 1.5 and 2.5% UPPA are 14.4 and 12.2N/mm2 respectively representing decrease of 29.32 and 40.01% respectively with the control mix. At later age, the strength development is observed to be on the increase with concrete containing admixtures. At 90-day, control sample has strength of 23.32N/mm2 which is about 12.56% higher than 28-day strength, concrete with 1.5 and 2.5% RRPA have strength of 22.77N/mm2 (28.50% increase), 20.64N/mm2 (32.40% increase) respectively while 1.5 and 2.5% UPPA concrete have strength of 20.86N/mm2 (31.00% increase) and 19.02N/mm2 (35.70% increase). Keywords---- Admixture, Compressive strength, Ripe plantain peel, Unripe plantain peel, Workability.