Akademik Veri Yönetim Sistemi
CONSTRUCTION AND BUILDING MATERIALS, cilt.514, 2026 (SCI-Expanded, Scopus)
The need for eco-efficient and lightweight construction materials has stimulated research on alkali-activated systems utilizing industrial by-products and porous aggregates. This study aims to develop and optimize fly ash-expanded perlite lightweight geopolymer composites (LGCs) by assessing the influence of nano-clay (NC) and basalt fibers (BF) on their mechanical, thermal, and durability performance. The specific objective was to clarify whether NC can refine the microstructure and improve thermal resistance, and whether BF can compensate for strength and durability limitations typically associated with lightweight systems. To achieve this, sixteen mixtures were designed with NC contents of 0-5 wt% and BF dosages of 0-0.75 % by volume. A comprehensive experimental program included compressive and flexural strength tests, density, porosity, water absorption, sorptivity, thermal conductivity, and exposure to high temperature (up to 750 degrees C), freeze-thaw cycles, and MgSO4 solution. Microstructural characterization was performed using SEM/EDS to relate matrix morphology and fiber-gel interaction to macroscopic performance. The findings revealed that NC consistently reduced strength and durability due to excessive viscosity, porosity, and incomplete geopolymerization, though higher NC levels provided partial benefits in thermal stability by forming alumina-rich gels. In contrast, BF significantly improved mechanical properties, reduced permeability, and enhanced crack resistance at 0.25-0.50 % dosages, whereas excessive BF (0.75 %) caused clustering and voids that undermined performance. Expanded perlite contributed to low density (approximate to 1060-1400 kg/m3) and thermal conductivity (0.35-0.70 W/ m center dot K), confirming the suitability of these composites for lightweight and insulating applications. The study demonstrates that NC addition is detrimental to mechanical and durability properties but can improve thermal stability, while optimized BF reinforcement is essential to balance structural integrity and insulation performance. These results provide valuable guidance for the tailored design of eco-efficient lightweight geopolymers in sustainable construction.