Influence of Sharp Sand and Stone Dust Combinations on the Properties of Wood Ash Blended Cement Concrete
1 *Raheem, A. A., and 2 Ajibola, E. O.
1,,Department of Building, Ladoke Akintola University of Technology, Ogbomoso, Oyo state, Nigeria.
2Department of Civil Engineering, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
DOI: 10.36108/laujoces/6202.71.0192
Abstract
Concrete production relies heavily on Portland limestone cement and natural sharp sand, contributing to environmental degradation and resource depletion. This study investigated stone dust as a partial or complete replacement for sharp sand in concrete containing 10% wood ash as cement replacement. Five mixes were produced at a nominal 1:2:4 proportion and water-to-binder ratio of 0.50, with stone dust replacing sharp sand at 0%, 25%, 50%, 75%, and 100%. Wood-ash chemical composition was determined by X-ray fluorescence, while aggregate particle-size distribution was evaluated in accordance with BS 812-103.1:1985. Slump and compacting factor tests followed BS EN 12350-2:2009 and BS 1881-103:1983, respectively. Compressive strength, splitting tensile strength, water absorption, and density were determined in accordance with BS EN 12390-3:2009, ASTM C496/C496M-17, and ASTM C642-13, respectively. Selected 28-day samples were examined using scanning electron microscopy. The combined SiO₂, Al₂O₃, and Fe₂O₃ content of the wood ash was 83.91%. Slump and compacting factor values ranged from 58–75 mm and 0.78–0.92, respectively. Compressive strength ranged from 8.00–25.20 N/mm², with 28-day values of 20.90–23.40 N/mm². Splitting tensile strength ranged from 0.90–3.50 N/mm², while water absorption and density ranged from 0.71–2.04% and 2387–2453 kg/m³, respectively. SEM images showed a compact microstructure in the 50% sharp sand and 50% stone dust combination samples. Material cost ranged from ₦24,000–₦25,130 per batch. These findings demonstrate that stone dust is a technically viable alternative to sharp sand in wood ash blended concrete.
Keywords: Wood ash; Stone dust; Sharp sand; Blended Cement Concrete; Compressive Strength; Sustainable Construction.