Blended binders in cement and concrete refer to the combination of Portland cement with one or more supplementary cementitious materials (SCMs) such as fly ash, slag, or silica fume. These materials are blended to enhance the physical and chemical properties of concrete, making it more suitable for various applications while reducing the environmental impact of construction. The primary purpose of using blended binders is to improve the sustainability of concrete by reducing the clinker content in cement, which in turn lowers carbon dioxide emissions during production. Additionally, blended binders can enhance the durability and performance of concrete, particularly in harsh environmental conditions. This is crucial for structures exposed to aggressive chemical attacks, thermal cycling, and other severe stressors that can lead to premature deterioration.