Simultaneous Optimization of Strength and Acid Resistance in Concrete Composed of Carbonated Fly Ash

Abstract

Fly ash that has captured carbon dioxide is regarded as carbonated fly ash. Use of this as a cement replacement can help in concreting in economically and environmentally beneficial way. For the purpose, the strength and durability aspect need careful investigation. In the current work, three cementitious materials such as fly ash, carbonated fly ash and fine crusher dust have been used as supplementary cementitious materials in concrete for finding strength and durability properties. Three levels of replacement (20, 40, 60%) have been considered to design M30 grade of concrete at water/cement ratio of 0.35. The cube compressive strength of concrete at water-curing age of 7, 28 and 90 days and the acid (5% H2SO4) resistance of those 7, 28 and 90 days water-cured concrete at 30 and 90 days acid exposure has been determined and compared with that of control concrete. Multi-response optimization using Taguchi method and grey relational analysis has been used to find process parameters towards simultaneous optimization of strength and durability. The carbonated fly ash concrete with cement replacement of 40% and 90 days of water curing offers simultaneously optimized strength and durability.