Mechanical Performance Enhancement of Alkali-Activated Composites Using Synthetic Fibers with Metazeolite and Aluminum Sludge-Based Recycled Concrete Aggregates

Abstract

This study examines the substantial enhancement in the performance of alkali-activated composites (AACs) produced from a distinctive combination of metazeolite (MZ) and slag (S), reinforced with synthetic fibers, and augmented with aluminum sludge (AS) and recycled concrete aggregate (RCA). The composites were subjected to activation through the use of a specific sodium hydroxide (NaOH) and sodium silicate (Na₂SiO₃) blend in a 2:1 ratio, with an activator-to-binder ratio of 0.95. Through a process of experimentation, the research team identified an optimal mix by varying the molarities of sodium hydroxide (NaOH) between 8M and 14M and the ratios of metazeolite to slag between 25% and 100%. The aforementioned mixture, comprising 50% MZ and 50% S, was activated with 12M NaOH and enhanced with 30% aluminum sludge, exhibiting remarkable strength characteristics. Furthermore, the incorporation of synthetic fibres, including polyethylene (PEF), polyamide (PAF), and basalt fibers (BF), resulted in a notable enhancement of the material's performance. It is noteworthy that the addition of basalt fibers at a concentration of 0.5% resulted in a 7% increase in compressive strength and a 24% improvement in flexural strength. This pioneering research illuminates the transformative potential of MZ-S-based AACs, particularly when combined with AS and BF, paving the way for the development of sustainable construction materials that meet contemporary performance and environmental standards.