Strength Properties of High-Performance Concrete with Green Banana (Musa acuminata) Peel Ash as Partial Cement Replacement

This study investigated the suitability of using green banana peel ash (GBPA) as a partial replacement for cement in high-performance concrete (HPC). Green banana peels were collected, dried, and burned at a controlled temperature of 800°C to produce ash, which was then ground and sieved through a 75 µm sieve. The physical and chemical characteristics of GBPA were evaluated through particle size analysis, X-ray fluorescence (XRF), and X-ray diffraction (XRD) analyses. The XRF results showed SiO₂ content of 29.989%, Al₂O₃ of 3.706%, and Fe₂O₃ of 1.294%. The physical properties revealed a specific gravity of 2.34 and moisture content of 1.0%. Concrete mixes were prepared with GBPA replacing cement at 0% (control), 5%, 10%, 15%, and 20% by weight, maintaining a constant water-cement ratio of 0.30 and total binder content of 450 kg/m³. A total of 90 specimens were cast and tested for compressive strength and splitting tensile strength at 7, 14, and 28 days of curing. The control mix achieved compressive strength of 55.87 MPa at 28 days, while the 5% GBPA replacement achieved 48.51 MPa, 10% achieved 39.34 MPa, 15% achieved 30.45 MPa, and 20% achieved 28.31 MPa. Splitting tensile strength followed a similar trend, with the control achieving 4.64 MPa at 28 days, while GBPA-modified mixes ranged from 3.11 MPa to 3.96 MPa. The relationship between compressive and splitting tensile strengths showed strong correlation with an R² value of 0. 9797.The study concludes that all GBPA replacement levels resulted in reduced mechanical properties compared to the control mix, with the 5% replacement showing the highest strength among GBPA mixes at 48.51 MPa (13.2% lower than control and 3.2% lower than the target). Characterization of GBPA showed pozzolanic properties below the standard requirements. The findings indicate that GBPA at 5% replacement achieved 48.51MPa of compressive strength which is almost comparable to the target strength for HPC (50MPa). Additionally, it showed having acceptable tensile strength at 28 days of curing.