Semnan University Press Journal of Transportation Infrastructure Engineering 2423-5350 11 4 2026 02 20 Evaluation and Modeling of Fatigue in Asphalt Mixtures Containing Expanded Clay Aggregates (LECA) and Nano-Alumina Modified Bitumen Based on Bitumen Fatigue Parameters Evaluation and Modeling of Fatigue in Asphalt Mixtures Containing Expanded Clay Aggregates (LECA) and Nano-Alumina Modified Bitumen Based on Bitumen Fatigue Parameters 49 78 10342 10.22075/jtie.2025.39226.1739 FA Ghasem Tahmouresi Department of Civil Engineering, Am.C., Islamic Azad University, Amol, Iran Mohsen Amouzadeh Omrani Faculty member, Islamic azad university, savadkouh branch, civil engineering department, Amol, Iran Hassan Divandari Department of Civil Engineering, CT.C., Islamic Azad University, Tehran, Iran, Ali Seyedkazemi Department of Civil Engineering, Am.C., Islamic Azad University, Amol, Iran Journal Article 2025 09 30 The use of Nano-Al₂O₃ to enhance durability of asphalt mixtures containing expanded clay aggregates (LECA) represents a sustainable and innovative approach in pavement engineering. In this study, 85–100 penetration-grade bitumen was modified with 0%, 1%, 2%, and 3% Nano-Al₂O₃ using a high-shear mixer, and the binder was evaluated through physical and rheological tests, including penetration, softening point, ductility, and kinematic viscosity. The RTFO and PAV aging processes were subsequently applied, and the aged binders were examined using DSR test to assess their rheological behavior. Moreover, asphalt mixtures incorporating 0%, 25%, and 50% LECA were subjected to Marshall stability, dynamic creep, and fatigue life tests to investigate the combined effects of these additives on mechanical performance, creep behavior, and fatigue resistance. The physical tests of bitumen indicated that Nano-Al₂O₃ addition improved the softening point, provided controlled stiffness, enhanced ductility, and increased viscosity. Rheological results showed that Nano-Al₂O₃ reduced mass loss and improved rutting and fatigue indices, indicating delayed cracking and increased pavement durability. Dynamic creep tests revealed that the incorporation of Nano-Al₂O₃ and optimal LECA replacement reduced cumulative strain and slowed the accelerated growth rate in the tertiary creep phase. Fatigue life tests demonstrated that the 25% LECA + 2%Al₂O₃ mixture exhibited the best performance, confirming that although elevated temperature and high stress levels accelerate fatigue damage, this mixture effectively mitigated these adverse effects and delayed deterioration. Regression modeling indicated that percentages of Nano-Al₂O₃ and LECA aggregates had a significant impact (p < 0.05) on fatigue life. The models achieved high coefficients of determination (R² = 0.928, 0.947, and 0.937 for 0%, 25%, and 50% LECA, respectively), accurately predicting the fatigue behavior of the mixtures. These results demonstrate the suitability and generalizability of the models for design of durable asphalt pavements. The use of Nano-Al₂O₃ to enhance durability of asphalt mixtures containing expanded clay aggregates (LECA) represents a sustainable and innovative approach in pavement engineering. In this study, 85–100 penetration-grade bitumen was modified with 0%, 1%, 2%, and 3% Nano-Al₂O₃ using a high-shear mixer, and the binder was evaluated through physical and rheological tests, including penetration, softening point, ductility, and kinematic viscosity. The RTFO and PAV aging processes were subsequently applied, and the aged binders were examined using DSR test to assess their rheological behavior. Moreover, asphalt mixtures incorporating 0%, 25%, and 50% LECA were subjected to Marshall stability, dynamic creep, and fatigue life tests to investigate the combined effects of these additives on mechanical performance, creep behavior, and fatigue resistance. The physical tests of bitumen indicated that Nano-Al₂O₃ addition improved the softening point, provided controlled stiffness, enhanced ductility, and increased viscosity. Rheological results showed that Nano-Al₂O₃ reduced mass loss and improved rutting and fatigue indices, indicating delayed cracking and increased pavement durability. Dynamic creep tests revealed that the incorporation of Nano-Al₂O₃ and optimal LECA replacement reduced cumulative strain and slowed the accelerated growth rate in the tertiary creep phase. Fatigue life tests demonstrated that the 25% LECA + 2%Al₂O₃ mixture exhibited the best performance, confirming that although elevated temperature and high stress levels accelerate fatigue damage, this mixture effectively mitigated these adverse effects and delayed deterioration. Regression modeling indicated that percentages of Nano-Al₂O₃ and LECA aggregates had a significant impact (p < 0.05) on fatigue life. The models achieved high coefficients of determination (R² = 0.928, 0.947, and 0.937 for 0%, 25%, and 50% LECA, respectively), accurately predicting the fatigue behavior of the mixtures. These results demonstrate the suitability and generalizability of the models for design of durable asphalt pavements. https://jtie.semnan.ac.ir/article_10342_65e0d1ccf215935a6903bc9c99aab75a.pdf