Akademik Veri Yönetim Sistemi
Construction and Building Materials, cilt.527, 2026 (SCI-Expanded, Scopus)
High cost and ecological footprint of polyvinyl alcohol (PVA) fibers hinder the sustainability of Engineered Cementitious Composites (ECCs). This study proposes a novel multi-scale hybrid fiber strategy incorporating multi-length polypropylene (PP) fibers (6 mm and 12 mm) and a previously unexplored high-aspect-ratio (49:1) synthetic wollastonite (SW) microfibers through dual-, triple-, and quad-hybrid ECC systems. A comprehensive experimental program evaluated fresh, mechanical (compressive and flexural), ultrasonic pulse velocity (UPV), and microstructural (FTIR, TGA, SEM) properties of mixtures. The experimental results demonstrated that replacing PVA with PP fibers reduced flowability, compressive strength, flexural performance, and UPV due to PP’s low stiffness, hydrophobic surface, and induced porosity during mixing. Longer PP fibers further decreased compressive strength (up to 19%) but improved ductility (up to 9%) through enhanced macro-crack bridging, compared to shorter PP fibers. In contrast, SW microfibers significantly improved compressive strength, flexural capacity, UPV, and matrix densification, as evidenced by pronounced C–S–H development and increased hydration degree in microstructural test results. The incorporation of SW microfibers increased compressive and flexural strengths by up to 12% and 7%, respectively, compared to control mixture. Triple-hybrid mixtures (PVA, 6 mm PP, 12 mm PP) exhibited intermediate behavior, while the quad-hybrid system (PVA, 6 mm PP, 12 mm PP, SW) achieved higher overall performance than triple-hybrid mixtures through a synergistic multi-scale reinforcement mechanism: SW densified the matrix, whereas PP and PVA fibers controlled macro- and micro-crack propagation. Additionally, sustainability assessment showed that fiber hybridization reduces embodied energy, carbon emission, and material cost by limiting PVA usage. The findings confirm that strategic fiber hybridization enables the development of high-performance and more sustainable ECCs with strong potential for both advanced and large-scale structural applications.