Optimization and Performance of Sustainable Mortar Incorporating High-Volume Alkali Bypass Dust: A Synergistic...

This study investigates the use of Alkali Bypass Dust (ABD), a cement kiln waste, as a supplementary cementitious material in mortar. Direct ABD incorporation reduced workability and strength. A dual-modification strategy employing a water reducer (WR) and silica fume (SF) was implemented. Mortars with 0-50% cement replaced by ABD were tested, with and without modifiers. Results showed that WR effectively restored workability and improved early strength, while SF enhanced long-term performance through pozzolanic reactions. A synergistic effect in ternary blends (ABD + WR + SF) yielded 28-day compressive strength at 50% ABD replacement comparable to the control (49.9 MPa). Statistical analysis via Response Surface Methodology confirmed that material interactions, not individual amounts, primarily govern strength development. All models are significant where R² value is higher than 0.80. The statistically validated models can be used to optimize the mix proportions for desired compressive and flexural performance. The study concludes that optimized blends with 30-50% ABD are viable for non-structural applications, offering a sustainable pathway for waste valorization and reduced cement consumption.