Effect of Mix design parameters on the properties of cementitious composites incorporating volcanic ash and dune sand

Abstract

This study examines the properties of cementitious composites incorporating volcanic ash (VA) and dune sand. The effect of five mix design parameters was studied using the Taguchi method. The fresh, mechanical, and durability properties of sixteen mixes were evaluated. To convert the evaluation from single criterion to multi-criteria, a hybrid Taguchi-TOPSIS was employed. Results showed that the optimum composite mix was made with a binder content of 500 kg/m3, a water-to-binder ratio of 0.5, VA replacement of 20%, dune sand replacement of 20%, and SP content of 0.75%. The optimum mix had a flow, final setting time, 28-day compressive strength, volume of permeable voids, and calcium leaching strength retention of 175 mm, 440 min, 50.5 MPa, 11.3%, and 78.8%, respectively. Portlandite, tobermorite, and gismondine were characterized as hydration products, while calcite and dolomite were also detected. This work provides an advanced understanding of the impact of mix design parameters on various properties while optimizing their levels for superior performance.

Keywords

• Volcanic ash
• Dune sand
• Cementitious
• Sustainability
• Environment
• Superplasticizer