Effect of Metakaolin and Steel–PVA Hybrid Fibers on Fresh, Mechanical, and Durability Properties of Mortars under Sulfuric Acid Attack
Journal of Materials Engineering and Performance, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s11665-026-15062-9
- Dergi Adı: Journal of Materials Engineering and Performance
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Applied Science & Technology Source, Chemical Abstracts Core, Compendex, INSPEC, Engineering Source (EBSCO), Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Anahtar Kelimeler: durability performance, metakaolin, residual strength, steel and PVA fibers, sulfuric acid attack
- Van Yüzüncü Yıl Üniversitesi Adresli: Evet
Özet
Sulfuric acid attack (SLA) is one of the most aggressive deterioration mechanisms affecting cementitious materials, leading to severe microstructural degradation and loss of mechanical performance. Although metakaolin (MK) and fiber reinforcement have individually demonstrated beneficial effects on durability, their combined influence under sulfuric acid exposure has not been sufficiently clarified. This study investigates the synergistic effects of MK together with steel (ST) and polyvinyl alcohol (PVA) fibers on the fresh, mechanical, and durability performance of cement mortars subjected to SLA. Eight mortar mixtures were produced, including a control mixture and mixtures incorporating 20% MK with single or hybrid fiber systems at different volume fractions. Fresh properties, water absorption (WA), mass loss (ML), residual compressive strength (RCS), and residual flexural strength (RFS) were evaluated after exposure to SLA, while x-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were performed to elucidate the underlying deterioration mechanisms. The results demonstrated that MK significantly enhanced matrix compactness and reduced the extent of acid-induced degradation through pore refinement and the formation of additional C-S-H gel. Furthermore, hybrid ST–PVA fiber reinforcement provided more effective crack control and superior retention of mechanical properties than single-fiber systems by combining macro-crack bridging with micro-crack suppression. Microstructural observations confirmed reduced gypsum formation, lower crack density, and a denser matrix in MK- and hybrid fiber-modified mortars.