Experimental and predictive analysis of thermal and mechanical performance of polypropylene fiber-reinforced concrete under extreme temperatures
Journal of Engineered Fibers and Fabrics, cilt.21, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 21
- Basım Tarihi: 2026
- Doi Numarası: 10.1177/15589250261478292
- Dergi Adı: Journal of Engineered Fibers and Fabrics
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC, Directory of Open Access Journals, Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Anahtar Kelimeler: concrete, fire resistance, polypropylene fiber, high temperature, residual strength, thermal degradation
- Atatürk Üniversitesi Adresli: Evet
Özet
This study establishes critical performance thresholds for polypropylene fiber (PPF) reinforced concrete exposed to extreme temperatures up to 700°C. Five concrete groups with PPF volume fractions of 0%, 0.15%, 0.25%, 0.35%, and 0.50% were systematically tested post- high temperature exposure for residual thermal conductivity, compressive/flexural strength, dynamic modulus of elasticity, and ultrasonic pulse velocity and were duly complemented by microstructural analysis. Results identify a pivotal degradation temperature of 500°C, beyond which all mixes suffered severe property loss. However, PPF incorporation demonstrably improved fire resistance. An optimal dosage of 0.25% PPF increased ambient compressive strength by 19% and most effectively mitigated strength loss after high-temperature exposure. All PPF mixes reduced thermal conductivity, with a maximum 12% reduction at 0.50% dosage. Microstructural evidence indicates that melted PPF creates pathways to relieve internal vapor pressure, delaying damage. The predictive modelling results were also quantified: on independent test data, XGBoost achieved R2 values of 0.9442–0.9815, while GPR achieved R2 values of 0.9549–0.9824 across the five target properties. For compressive and flexural strength, GPR produced lower RMSE values than XGBoost (2.7944 MPa vs. 2.9923 MPa, and 0.2377 MPa vs. 0.4191 MPa, respectively), while also providing uncertainty estimates for reliability-based interpretation. The findings deliver clear, dosage-dependent guidelines for material design, defining the specific fiber content and temperature thresholds that govern residual performance. This work provides essential criteria for optimizing PPF concrete to enhance structural fire resistance.