Strength Properties of Banana (Musa spp) Bud Ash Concrete

Abstract

The use of Banana (Musa spp) Bud Ash (BBA) in concrete is among the options of achieving waste reduction, protecting the environment, and achieving sustainability. This report presents the results of the workability and compressive strength on the use of BBA as partial replacement for Ordinary Portland Cement (OPC) in concrete. Banana buds collected from farms in Ikole-Ekiti were burnt with an uncontrolled temperature to ash. River sand, 20 mm coarse aggregates, a M15 concrete grade, mix proportion of 1:2:4 and water cement ratio of 0.6 was used. The BBA/OPC mix used by weight were 0/100%, 10/90%, 20/80%, 30/70%, 40/60% and 50/50% to produce 54 cubes of 150 mm x150 mm x 150 mm size.  Curing was done by immersion for 7, 28 and 56 days. BBA consists of majorly SiO₂ (48.7 %), CaO (21.3 %), Fe₂O₃ (1.4 %), Al₂O₃ (2.6 %), MgO (0.96 %), and other elements. The workability results decreased with increased percentages of BBA with 80.5 mm and 67.0 mm for 0% and 50% respectively. The compressive strength (N/mm²) at 7, 28 and 56 days were 16.4, 24.9 and 55.6 for 0%, and 8.20, 15.2 and 44.4 for 50% of BBA, respectively. The percentage strength gained at 56 days for 10 and 20% for the control of 0% is 95.68 % and 91.74% respectively. Compressive strength decreases with increasing BBA content but increases with age. The optimum compressive strength of 53.2 N/mm² was obtained at 10% replacement at 56 days of ages. BBA concrete can perform well in floor and wall applications when a 10% replacement is not exceeded.