Improvement and predictive modeling of the mechanical performance of waste fire clay blended concrete


Creative Commons License

Özkılıç Y. O., Zeybek Ö., Karalar M., Çelik A. İ.

REVIEWS ON ADVANCED MATERIALS SCIENCE, sa.64, ss.1-20, 2025 (SCI-Expanded, Scopus)

Özet

In this study, waste fire clay (WFC) was used to replace up to 50% of the fine aggregate (FA) and cement in the production of concrete. Mechanical tests were carried out to determine the compressive strength (CS), splitting tensile strength (STS), and flexural strength (FS) of the con crete. The results showed that the use of WFC as a replace ment of FA significantly improved the mechanical properties, with the highest performance achieved at a replacement level of 20%. At this level, FS increased by 25.6%, while improve ments of 11.5, 18, 12.8, and 7.7% were recorded at replacement levels of 10, 30, 40, and 50%, respectively. At replacement levels above 30%, the CS values started to decrease, with a loss in strength of 4.2–10% compared to the reference sample. Replacement of cement with WFC hadanegative effect onthe mechanical strength of the concrete, resulting in significant decreases inCSvalues ranging from12.2 to68%. Similar decreasesofupto63%inSTSvalueswerealsoobserved when cement was replaced. In the study, concrete properties were estimated using empirical formulae based on ACI 318 and Eurocode 2 (EC2) standards, together with autoregressive (ARX) models with external inputs; these models showed high agreement with experimental data and demonstrated strong applicability in the field. Scanning electron microscopy (SEM) analyses showed that matrix formation was improved at the optimum WFC ratio; however, hydration was negatively  * Corresponding author: Yasin Onuralp Özkılıç, Department of Civil Engineering, Faculty of Engineering, Necmettin Erbakan University, Konya, 42000, Turkey, e-mail: yozkilic@erbakan.edu.tr Özer Zeybek: Department of Civil Engineering, Faculty of Engineering, Mugla Sitki Kocman University, Mugla, 48000, Turkey Memduh Karalar: Department of Civil Engineering, Zonguldak Bulent Ecevit University, Zonguldak, Turkey Ali İhsan Çelik: Kayseri Üniversitesi Tomarza Mustafa Akincioglu Vocational School, Department of Construction, Kayseri University, Kayseri, 38940, Turkey Essam Althaqafi: Civil Engineering Department, College of Engineering, King Khalid University, Abha 61421, Saudi Arabia affected by void formation at high replacement ratios. These results demonstrate that WFC, when used at appro priate ratios, can serve as a valuable additive to improve concrete performance and contribute to sustainable con struction applications. All results indicate that WFC, when used at appropriate replacement ratios, can improve the mechanical properties of concrete and contribute to the development of sustainable construction materials.