Ramez M. Hajj
Primary Research Area
- Transportation Engineering
Research Areas
For More Information
Biography
Ramez Hajj is an Assistant Professor in the department of Civil and Environmental Engineering. Prior to joining UIUC, he completed his Ph.D. and Master's in Civil Engineering at the University of Texas at Austin. He obtained his Bachelor's Degree in Civil Engineering with a minor in Engineering Science and Mechanics from Virginia Tech. Dr. Hajj's research spans everything related to asphalt materials and flexible pavements, from as small as investigating asphalt binder behavior at the molecular, nano-, and micro-scale, to developing novel materials for roadway pavement and railroad trackbed applications, to solving network-level transportation infrastructure problems. Primarily, his research focuses on asphalt binders, mixtures, and pavements, but more broadly, these research areas are situated in wider research areas of viscoelasticity, composites, machine learning and computational modeling. So far, his work includes fundamental scientific discoveries into the origins of cracking in asphalt binder microstructure, as well as practical contributions to the asphalt industry, state Departments of Transportation, and local transportation agencies. To date, he has published in a wide range of peer-reviewed journals in these areas, and presented his work at many international conferences. Dr. Hajj's research is funded by the Illinois Department of Transportation (IDOT), the US Department of Agriculture (USDA), Minnesota Department of Transportation (MnDOT), the Smart Transportation Infrastructure Initiative (STII), the Illinois-Indiana Sea Grant, and numerous industry partners.
Education
- Bachelor of Science, Civil Engineering, Virginia Tech, 2014
- Master of Science, Civil Engineering, The University of Texas at Austin, 2016
- Doctor of Philosophy, Civil Engineering, The University of Texas at Austin, 2019
Academic Positions
- Assistant Professor, Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Jan. 2020 - Present
Journal Editorships
- Editorial Board Member (2022 - 2025), Road Materials and Pavement Design (Taylor & Francis)
- Junior Editorial Board Member (2021 - Present), Journal of Infrastructure Preservation and Resilience (Springer Open)
- Associate Editor (2025 - Present), Road Materials and Pavement Design (Taylor & Francis)
Professional Societies
- AKM 20 - Standing Committee on Asphalt Binders, Member and Research Coordinator, Transportation Research Board, National Academies of Science, Engineering, and Medicine, 2020 - 2025
- Academy of Pavement Science and Engineering, Academic Member, 2020 - Present
- American Society of Civil Engineers, Associate Member, 2020 - Present
- Engineering Mechanics Institute, ASCE, Member, 2020 - Present
- Association of Asphalt Paving Technologiests (AAPT), Member and Serving on Newer Member Committee, 2020 - Present
- Mechanics of Pavements Committee, Member, ASCE EMI, 2021 - Present
- AKM 40 - Standing Committee on Asphalt Mixture Evaluation and Performance, Member, Transportation Research Board, National Academies of Science, Engineering, and Medicine, 2022 - 2025
- Transportation and Development Institute, ASCE, Member, 2022 - Present
- Society of Rheology, Member, 2022
- American Society of Civil Engineers East Central Branch, Vice President, 2023 - Present
- Transportation Research Board Committee Research Coordinators Council, National Academies of Science, Engineering, and Medicine, Materials Representative, 2025
Service on Department Committees
- Transportation QE Coordinator, 2025 - Present
- Transportation Scholarship Committee, Chair, 2022 - Present
- CEE THRIVES Committee Member and coordinator of Assistant Professor subgroup, 2022 - Present
- Search Committee Member, Research Scientist, Department of Civil and Environmental Engineering (2021)
- Search Committee Chair, Research Engineer, Illinois Center for Transportation (2021)
- Search Committee Member, Senior Research Scientist, Illinois Center for Transportation (2020)
- Planning Committee, Illinois Bituminous Paving Conference (2020 - Present)
Service on College Committees
- Peer Observer, Collins Scholar Program, 2021
- Diversity Committee, Member, Grainger College of Engineering, 2020 - 2021
- Member, IDEA Institute, 2020 - Present
- Grainger College of Engineering Ombudsperson Position Development Committee, Member, 2020
Service on Campus Committees
- Facilitator, Mentoring Matters Series, Office of the Associate Provost for Academic Affairs, Spring 2022 and Summer 2023, Panelist Summer 2025
Service to Federal and State Government
- Project Panel on Friction and Texture Performance Evaluation for Asphalt Mixtures, Panel Member, National Cooperative Highway Research Program, Transportation Research Board, National Academies of Science, Engineering, and Medicine. 2025 - Present.
- Project Panel on Pavement Marking Friction Levels and Testing Methods Needed for Road Users (vehicular and vulnerable users, i.e. motorcycles and bicycles), Panel Member, National Cooperative Highway Research Program, Transportation Research Board, National Academies of Science, Engineering, and Medicine. 2024 - Present.
- Project Panel on Performance-Based Tests for Asphalt Emulsion Treatments as part of Agency Acceptance and Incentive Programs, Panel Member, National Cooperative Highway Research Program, Transportation Research Board, National Academies of Science, Engineering, and Medicine. 2024 - Present.
- Engineering Research Visioning Alliance Sustainable Transportation Networks Committee, National Science Foundation, 2022. Final Report: https://www.ervacommunity.org/visioning-report/sustainable-transportation-networks/
- Academic Representative, Pavements and Materials Technical Advisory Group, Illinois Department of Transportation, 2022 - 2025
Other Outside Service
- External Merit Reviewer, University of Balamand Internal Research Fund, 2025.
- External Grant Reviewer, Swiss National Science Foundation, 2021 - Present
- External Grant Reviewer, Research Grants Council (RGC) of Hong Kong, 2020 - Present
- Technical Reviewer for Journals including: Cleaner Materials (Elsevier), Construction and Building Materials (Elsevier), Energy & Buildings (Elsevier), Engineering Applications of Artificial Intelligence (Elsevier), Fuel (Elsevier), International Journal of Solids and Structures (Elsevier), Mechanics of Materials (Elsevier), Transportation Geotechnics (Elsevier), International Journal of Pavement Engineering (Taylor and Francis), Journal of Adhesion Science & Technology (Taylor & Francis), Mechanics Based Design Of Structures And Machines (Taylor & Francis), Molecular Simulation (Taylor & Francis), Road Materials and Pavement Design (Taylor and Francis), Materials and Structures (Springer), ACS Applied Nano Materials (ACS Publications), ACS Sustainable Resource Management (ACS Publications), Energy & Fuels (ACS Publications), Journal of Cold Regions Engineering (ASCE), Journal of Engineering Mechanics (ASCE), Journal of Materials in Civil Engineering (ASCE), Journal of Transportation Engineering Part B: Pavements (ASCE), Journal of Risk and Uncertainty in Engineering Systems Part B: Mechanical Engineering (ASME), Journal of Testing and Evaluation (ASTM), Transportation Research Record: Journal of the Transportation Research Board (SAGE Publishing), Reviews on Advanced Materials Science (Degruyter), International Journal of Pavement Research and Technology (Springer Nature), Computer-Aided Civil & Infrastructure Engineering (Wiley), Fatigue & Fracture of Engineering Materials & Structures (Wiley), CivEng (MDPI), Coatings (MDPI), Infrastructures (MDPI), Materials (MDPI), Sustainability (MDPI), Canadian Journal of Civil Engineering (Canadian Science Publishing)
Research Interests
- Asphalt binder rheology and chemistry
- Mechanics of viscoelastic materials
- Computational modeling of infrastructure materials
- Flexible pavement design, construction, and maintenance
- Pavement surface characteristics and treatments
- Asphalt applications in railroad trackbeds
- Artificial intelligence for infrastructure material engineering
Primary Research Area
- Transportation Engineering
Research Areas
Selected Articles in Journals
- Ahmad, A., Kawale, H., Summers, S., Cantero, B. C. B., Allen, C. M., Hajj, R. M., Davidson, P.C., Zhang, Y. & Li, Y. (2025). Financial viability and carbon intensity of hydrothermal waste valorization systems for bio-based asphalt binder. Chemical Engineering Journal, 172283. https://doi.org/10.1016/j.cej.2025.172283
- Sallam, O., El-Rayes, K., Ignacio, E.J., Al-Ghzawi, M., & Hajj, R. “Analyzing the Effectiveness and External Noise Levels of Sinusoidal and Traditional Shoulder Rumble Strips.” Transportation Research Record: Journal of the Transportation Research Board, 03611981251400710. https://doi.org/10.1177/03611981251400710
- Lu, Y., Doehring, J., Garg, N., & Hajj, R. (2025) Multiscale experimental study of encapsulated rejuvenators for self-healing asphalt system. Cleaner Materials, 100356. https://doi.org/10.1016/j.clema.2025.100356
- Sallam, O., El-Rayes, K., Ignacio, E.J., Hajj, R., & Al-Ghzawi, M. (2025) “Mitigating External Noise of Transverse Rumble Strips and Complaints from Nearby Neighborhoods” Transportation Research: Part D: Transport and Environment, 149, 105021. https://doi.org/10.1016/j.trd.2025.105021
- Wang, Y. & Hajj, R. (2025) Chemo-mechanical characterization of rejuvenated asphalt binder using data-driven approach and micro-mechanical models. Transportation Research Record: Journal of the Transportation Research Board, 03611981251387140. https://doi.org/10.1177/03611981251387140
- Adwani, D., Mirwald, J., Pipintakos, G., Sreeram, A., Hajj, R., & Bhasin, A. (2025) Historical insights on asphalt aging, mechanisms, and anti-aging technologies with evaluation of a potential antioxidant as the way forward. Construction and Building Materials, 493, 143055. https://doi.org/10.1016/j.conbuildmat.2025.143055
- Vyas, A. & Hajj, R. (2025) Exploring the use of reclaimed asphalt pavement in airfield asphalt mixes: insights from mixture and binder scale. Transportation Research Record: Journal of the Transportation Research Board, 03611981251357930. https://doi.org/10.1177/03611981251357930
- Asadi, B., Shah, V., Vyas, A., Golparvar-Fard, M., & Hajj, R. (2025) Hybrid Deep Learning Model for Predicting Failure Properties of Asphalt Binder from Fracture Surface Images. Computer-Aided Civil and Infrastructure Engineering. https://doi.org/10.1111/mice.13447
- Vyas, A., Maia, R.S., & Hajj, R. (2024) Cracking potential evaluation of recycled asphalt materials using the poker chip test and I-FIT. Road Materials and Pavement Design, 1-25. https://doi.org/10.1080/14680629.2024.2427871
- Maia, R. S., & Hajj, R. (2024). Laboratory and field evaluation of asphalt concrete modulus and critical strain inputs for ME flexible pavement design in the state of Illinois. Canadian Journal of Civil Engineering.
- Lu, Y., Cui, B., Wang, H., & Hajj, R. (2024). Experimental and simulation-based engineering of calcium alginate self-healing asphalt capsules. Chemical Engineering Journal, 499, 156212.
- Adwani, D., Pipintakos, G., Mirwald, J., Wang, Y., Hajj, R., Guo, M., ... & Bhasin, A. (2024). Examining the efficacy of promising antioxidants to mitigate asphalt binder oxidation: insights from a worldwide interlaboratory investigation. International journal of pavement engineering, 25(1), 2332363. https://doi.org/10.1080/10298436.2024.2332363
- Lu, Y., Maia, R. S., & Hajj, R. M. (2024). Backcalculation of asphalt concrete Poisson’s ratio using the ultrasonic pulse velocity test. Materials and Structures, 57(9), 202.
- Maia, R.S., Lu, Y., & Hajj, R. (2024) Porous Asphalt Performance in Cold Regions: Case Study of Chicago, Illinois. Case Studies on Construction Materials. Published Online. https://doi.org/10.1016/j.cscm.2024.e03250
- Maia, R.S., Hajj, R., Cunto, F.J.C., & Castelo Branco, V.T.F. (2024) Safety-focused Urban Pavement Design and Evaluation: Integrating Microscopic Simulation and Tire-Pavement Friction. nternational Journal of Pavement Engineering. Published Online. https://doi.org/10.1080/10298436.2024.2345138
- Asadi, B., & Hajj, R. (2024). Prediction of asphalt binder elastic recovery using tree-based ensemble bagging and boosting models. Construction and Building Materials, 410, 134154. https://doi.org/10.1016/j.conbuildmat.2023.134154
- Lu, Y., Maia, R.S., & Hajj, R. (2023). Multiscale evaluation of asphalt binder rejuvenation dosing and efficacy. Construction and Building Materials, 133813. https://doi.org/10.1016/j.conbuildmat.2023.133813
- Asadi, B., Hajj, R., & Al-Qadi, I. L. (2023). Asphalt concrete dynamic modulus prediction: Bayesian neural network approach. International Journal of Pavement Engineering, 24(2), 2270569. https://doi.org/10.1080/10298436.2023.2270569
- Vyas, A., Wang, Y., Hajj, R., & Jahns, E. (2023). Investigation of factors affecting modified binder design and performance using the poker chip test. Construction and Building Materials, 403, 133037. https://doi.org/10.1016/j.conbuildmat.2023.133037
- Husain, S., Qamhia, I., Vyas, A., Maia, R., Tutumluer, E., & Hajj, R. (2023). Emulsion mixtures of fractionated reclaimed asphalt pavement and quarry by-products: a laboratory evaluation. Sustainability, 15(13), 10735. https://doi.org/10.3390/su151310735
- Lu, Y., Asadi, B., & Hajj, R. (2023). Rheological, Mechanical, Microscopic, and Chemical Characterization of Asphalt Binders at Extended Aging Levels. Journal of Materials in Civil Engineering, 35(8), 04023256. https://doi.org/10.1061/JMCEE7.MTENG-15297
- Adwani, D., Sreeram, A., Pipintakos, G., Mirwald, J., Wang, Y., Hajj, R., Jing, R., & Bhasin, A. (2023) Interpreting the effectiveness of antioxidants to increase the resilience of asphalt binders: first of its kind global interlaboratory study. Construction and Building Materials, 366. https://doi.org/10.1016/j.conbuildmat.2022.130231
- Filonzi, A., Komaragiri, S., Hajj, R., Trevino, M., Hazlett, D., Mahmoud, E., & Bhasin, A. (2023). A method to evaluate the tensile strength and ductility of asphalt binders using a thin confined film. International Journal of Pavement Engineering, 24(2), 2031194. https://doi.org/10.1080/10298436.2022.2031194
- Lu, Y., & Hajj, R. (2021). Investigation of flexible pavement maintenance patching factors using a finite element model. Journal of Infrastructure Preservation and Resilience, 2(1), 30. https://doi.org/10.1186/s43065-021-00044-z
- Asadi, B., Tabatabaee, N. and Hajj, R. (2021) Use of linear amplitude sweep test as a damage resistance or fracture test to determine the optimum content of asphalt rejuvenator. Construction and Building Materials, 300. https://doi.org/10.1016/j.conbuildmat.2021.123983
- Asadi, B., Tabatabaee, N., and Hajj, R. (2021) Crack-based healing master curves derived from linear amplitude sweep tests: A cohesive healing indicator for asphalt binders. Accepted for publication in Materials and Structures. https://doi.org/10.1617/s11527-021-01727-5
- Ahmed, R. B., Hossain, K., Aurilio, M., & Hajj, R. (2021). Effect of rejuvenator type and dosage on rheological properties of short-term aged binders. Materials and Structures, 54(3), 1-18. https://doi.org/10.1617/s11527-021-01711-z
- Gul, M. A., Khan, K., Islam, M. K., Shalabi, F. I., Ozer, H., Hajj, R., & Bhasin, A. (2021). Developing a performance based mix design and evaluating the influence of various factors on sulfur-extended asphalt. Construction and Building Materials. 290, 123199. https://doi.org/10.1016/j.conbuildmat.2021.123199
- Hajj, R., & Young, S. (2021). An analysis of theoretical and empirical relationships between two asphalt binder cracking parameters. Road Materials and Pavement Design, 1-17. https://www.tandfonline.com/doi/abs/10.1080/14680629.2021.1906734
- Ahmed, R. B., Hossain, K., & Hajj, R. M. (2021). Chemical, morphological, and fundamental properties of rejuvenated asphalt binders. Journal of Materials in Civil Engineering, 33(2), 04020461. https://ascelibrary.org/doi/abs/10.1061/%28ASCE%29MT.1943-5533.0003564
- Sreeram, A., Leng, Z., Hajj, R., Ferreira, W. L., Tan, Z., & Bhasin, A. (2020). Fundamental investigation of the interaction mechanism between new and aged binders in binder blends. International Journal of Pavement Engineering, 1-11. (Completed 2019 before joining UIUC) https://doi.org/10.1080/10298436.2020.1799208
- Filonzi, A., Hajj, R., Smit, A. D. F., & Bhasin, A. (2020). Validation of inverse stereology generation of two dimensional area gradations for computational modelling of asphalt mixtures. Road Materials and Pavement Design, 1-15. (Submitted 2019 before joining UIUC) https://doi.org/10.1080/14680629.2020.1742194
- Filonzi, A., Lee, S. K., Ferreira, W., Hajj, R., & Bhasin, A. (2020). A micro-extraction method for use with 4 mm plate geometry in the Dynamic Shear Rheometer to evaluate asphalt binder rheology. Construction and Building Materials, 252, 119024. (Submitted 2019 before joining UIUC) https://doi.org/10.1016/j.conbuildmat.2020.119024
- Sakib, N., Hajj, R., Hure, R., Alomari, A., & Bhasin, A. (2020). Examining the relationship between bitumen polar fractions, rheological performance benchmarks, and tensile strength. Journal of Materials in Civil Engineering, 32(6), 04020143. (Submitted 2019 before joining UIUC) https://doi.org/10.1061/(ASCE)MT.1943-5533.0003197
- Hajj, R., Ramm, A., Bhasin, A., & Downer, M. (2019). Real-time microscopic and rheometric observations of strain-driven cavitation instability underlying micro-crack formation in asphalt binders. International Journal of Pavement Engineering, 21(8), 977-989. https://doi.org/10.1080/10298436.2019.1652742
- Hajj, R., Filonzi, A., Rahman, S., & Bhasin, A. (2019). Considerations for using the 4 mm plate geometry in the dynamic shear rheometer for low temperature evaluation of asphalt binders. Transportation Research Record, 2673(11), 649-659. https://doi.org/10.1177/0361198119855332
- Sreeram, A., Leng, Z., Hajj, R., & Bhasin, A. (2019). Characterization of compatibility between aged and unaged binders in bituminous mixtures through an extended HSP model of solubility. Fuel, 254, 115578. https://doi.org/10.1016/j.fuel.2019.05.161
- Hajj, R., Filonzi, A., Smit, A., & Bhasin, A. (2019). Design and performance of mixes for use as ultrathin overlay. Journal of Transportation Engineering, Part B: Pavements, 145(3), 04019026. https://doi.org/10.1061/JPEODX.0000130
- Sabaraya, I. V., Filonzi, A., Hajj, R., Das, D., Saleh, N. B., & Bhasin, A. (2018). Ability of nanomaterials to effectively disperse in asphalt binders for use as a modifier. Journal of Materials in Civil Engineering, 30(8), 04018166. https://doi.org/10.1061/(ASCE)MT.1943-5533.0002315
- Hajj, R., & Bhasin, A. (2018). The search for a measure of fatigue cracking in asphalt binders–a review of different approaches. International Journal of Pavement Engineering, 19(3), 205-219. https://doi.org/10.1080/10298436.2017.1279490
- Hajj, R., Hure, R., & Bhasin, A. (2017). Evaluation of stiffness, strength, and ductility of asphalt binders at an intermediate temperature. Transportation Research Record, 2632(1), 44-51. https://doi.org/10.3141/2632-05
Articles in Conference Proceedings
- Hajj, R. (2026). Sensitivity evaluation of temperature correction techniques for TSD data. In 12th International conference on Bearing Capacity of Roads, Railways, and Airfields; (12th BCRRA 2026). Ljubljana, Slovenia. In Press.
- Kong, T., Mahala, N., Vyas, A., Tutumluer, E., Hajj, R., & Ceylan, H. (2026). Assessment of Composite Modulus in Otta Seal Surfacing Utilizing Aggregate Quarry By-products. In 12th International Conference on Bearing Capacity of Roads, Railways, and Airfields; (12th BCRRA 2026). Ljubljana, Slovenia. In Press.
- Hajj, R. (2025). Multi-Scale Model for Studying Asphalt Overlayment-Crosstie Interface. In World Congress on Railway Research (WCRR). Colorado Springs, CO. In Press.
- Hajj, R. (2025). Work In Progress: Development of the Asphalt Road-eo Student Competition. In 2025 American Society of Engineering Education (ASEE) Annual Conference & Exposition. Portland, OR.
- Golecki, H. M., Chang, W. L., Wright, A., Shehab, S., Johnson, B. E., Hajj, R., King, C., Pascarella, P., & Cinnamon, L. H. (2025).Developing a Podcasting Platform to Support Engineering Education. In 2025 American Society of Engineering Education (ASEE) Annual Conference & Exposition. Portland, OR.
- Mann, J., Ansari, A., Chang, W. L., Cvetkovic, C., Golecki, H. M., & Hajj, R. (2025). Y (Our) story: A collaborative autoethnographic reflection of a faculty community of practice to promote equity-oriented engineering education. In 2025 American Society of Engineering Education (ASEE) Annual Conference & Exposition. Portland, OR.
- Vyas, A. & Hajj, R. (2025). Reintroducing the poker chip direct tension test for asphalt concrete mixtures. In Advances in Materials and Pavement Performance Prediction III: Contributions to the 4th International Conference on Advances in Materials and Pavement Performance Prediction (AM3P 2025). Vienna, Austria.
- Mann, J., Wright, A., Althaus, E. W., Chang, W. L., Ansari, A., Cvetkovic, C., Hajj, R,. & Golecki, H. M. (2025). Reflective Teaching Practices for Equity-Minded Engineering Instructors. In 2025 Collaborative Network for Engineering & Computing Diversity (CoNECD). San Antonio, TX.
- Thompson, M., Hajj, R., Wienrank, C., & Senger, J. (2024) Perpetual pavement design in Illinois- current and future practice. In NAPA Perpetual Pavements Conference. Louisville, KY.
- Maia, R. S., Asadi, B., Vyas, A., Lu, Y., Thompson, M., & Hajj, R. (2024). Dynamic Modulus Prediction Models for Illinois’ Full-Depth Asphalt Pavement ME Design Considering Modern Materials. In International Symposium on Asphalt Pavement & Environment (pp. 261-265).
- Pipintakos, G., Mirwald, J., Camargo, I., Sreeram, A., Keuliyan, F., Margaritis, A., Sulaiman, A., Alhalidi, Y., SkulteckÄ—, J., Hajj, R., & Elwardany, M. (2024) The Young Ageing Crew (YAC): bringing fresh ideas to the scientific community. In 8th International Conference on Bituminous Mixtures and Pavements. Thessaloniki, Greece.
- Asadi, B. & Hajj, R. (2024) Deep Neural Network for predicting dynamic modulus of asphalt concrete. In AM3P 2022: Advances in Materials, Pavement Performance, and Prediction. Hong Kong.
- Bond, M., Hajj, R., Roesler, J. R., Schmidt, A. R., & Henschen, J. (2023). A Near-Peer Mentoring Framework for a Civil and Environmental Engineering Curriculum. In 2023 ASEE Annual Conference & Exposition.
- Lu, Y., & Hajj, R. M. (2022) Viscoelastic finite element modeling of flexible pavement patching. In Green and Intelligent Technologies for Sustainable and Smart Asphalt Pavements: Proceedings of the 5th International Symposium on Frontiers of Road and Airport Engineering (IFRAE). Delft, Netherlands. CRC Press.
- Hajj, R., Ramm, A., Mohanraj, K., Bhasin, A., and Downer, M. (2020) Micro-scale observations of fatigue damage mechanism in asphalt binder. AM3P 2020: Advances in Materials, Pavement Performance, and Prediction. San Antonio, TX.
- Hajj, R. & Bhasin, A. (2020) Importance of triaxial stress state on asphalt binder tensile failure. AM3P2020: Advances in Materials, Pavement Performance, and Prediction. San Antonio, TX.
- Hajj, R., Sakib, N., Bhasin, A.,Ramm, A., and Downer, S. (2018). Relation of modified bitumen microstructure to cracking indicators. In Advances in Materials and Pavement Prediction, pp. 189-192. CRC Press.
- Sakib, N., Hajj, R., Bhasin, A., Ramm, A., and Downer, M. (2018) Bulk microstructures in bitumen and its influence on rheology. In Advances in Materials and Pavement Prediction, pp. 411-414. CRC Press.
- Komaragiri, S., Filonzi, A., Hajj, R., and Bhasin, A., and Motamed, A. (2018) Three-dimensional profiler for performance evaluation of chip seals. In Advances in Materials and Pavement Prediction, pp. 579-582. CRC Press.
- Tehrani, M., Boroujeni, A., Hajj, R., and Al-Haik, M. (2013) Mechanical Characterization of a Hybrid Carbon Nanotube/Carbon Fiber Reinforced Composite. In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers Digital Collection.
Abstracts (in print or accepted)
- Wang, Y., Sandoval-Campos, A., & Hajj, R. (2025). "Efficient HSP Determination for Asphalt Binders Using a Three-Solvent Titration Approach." In 62nd Petersen Asphalt Research Conference. Laramie, WY,
- Hajj, R. & Regmi, B. (2025) “Effect of hydrated lime on delaying oxidation in asphalt mastics.” In 62nd Petersen Asphalt Research Conference. Laramie, WY,
- Maia, R.S., Akwemoh, T., Owolabi, O., & Hajj, R. (2025). "Assessment of Post-Flooding Healing and Fatigue Life of Damaged Asphalt Concrete Mixes." In International Airfield and Highway Pavements Conference. Glendale, AZ.
- Asadi, B., Hajj, R., & Golparvar-Fard, M. (2025). "Hybrid CNN-Transformer Model for Predicting Failure Properties of Asphalt Binder from Fracture Surface Images. In Engineering Mechanics Institute Conference. Anaheim, CA,
- Asadi, B. & Hajj, R. (2025) Predicting Cracking in Asphalt Pavements: The Phase-Field Approach for Fine Aggregate Matrix and Asphalt Mixture. In Engineering Mechanics Institute Conference. Anaheim, CA,
- Hu, R., Asadi, B., Hajj, R., Kohler, E., Ouyang, Y., Tobias, P., & Wang, H. (2024) Development of a Pavement Friction Management Program. In 2024 AASHTO Safety Summit and Peer Exchange. Houston, TX.
- Hajj, R. (2024) History and Future of Mechanistic-Empirical Flexible Pavement Design in Illinois. In 100th Annual Meeting of the Association of Asphalt Pavement Technologists. Chicago, IL.
- Hajj, R. & Tofighian, M. (2024) Bio-binder and bio-rejuvenator synthesis from hydrothermal liquefaction. In 61st Peterson Research Conference. Laramie, WY.
- Hajj, R. (2024) Effects of confinement condition on ductility of asphalt binders. In Engineering Mechanics Institute Conference and Probabilistic Mechanics and Reliability Conference (EMI/PMC 2024). Chicago, IL.
- Hajj, R. (2023) Use of nonlinear tests and chemistry to understand anti-aging effect of an asphalt softener. In IRF Global R2T Conference & Exhibition. Phoenix, AZ.
- Hajj, R. (2023) Considerations for rejuvenating larger amounts of recycled asphalt binder. In International Conference on Resource Sustainability. Surrey, UK.
- Lu, Y. & Hajj, R. (2023) Experimental and simulation-based design of self-healing asphalt capsules. In 60th Peterson Research Conference. Laramie, WY.
- Vyas, A. & Hajj, R. (2023) Development of a New Balanced Mix Design (BMD) Framework that Incorporates Binder Tests. In ASCE Airfield and Highway Pavements Conference. Austin, TX
- Asadi, B. & Hajj, R. (2023) Strain field distribution in I-FIT test based on Digital Image Correlation. In ASCE Engineering Mechanics Institute 2023 Conference. Atlanta, GA.
- Hajj, R. (2022) Durability and maintenance demand of porous asphalt concrete in cold regions. In TriDurLE 2nd Annual Symposium. Honolulu, HI.
- Hajj, R. & Asadi, B. (2022) Data-driven generation of modulus and phase angle master curves. In 93rd Annual Meeting of The Society of Rheology. Chicago, IL.
- Hajj, R., Lu, Y., Maia, R. (2022) Investigation of laboratory techniques for evaluating rejuvenator effectiveness and dosage. In 59th Peterson Research Conference. Laramie, WY.
- Asadi, B. & Hajj, R. (2022) A data-driven model for master curves of viscoelastic materials. In ASCE Engineering Mechanics Institute 2022 Conference. Baltimore, MD.
- Hajj, R. (2020) Fundamental and empirical relationships between binder cracking indicators. In 57th Peterson Asphalt Research Conference. Laramie, WY.
Refereed Conference Papers and Presentations
- Maia, R.S., Regmi, B., & Hajj, R. "Effects of Partial Saturation and Moisture Damage on Immediate Recovery and Healing of Binder Course Asphalt Concrete Mixes." In Transportation Research Board 105th Annual Meeting. Washington, DC. 2026.
- Regmi, B., Maia, R.S., & Hajj, R. "Assessing the Moisture Susceptibility and Aging of Asphalt Mixes with Hydrated Lime Through Realistic Mixture Testing." In Transportation Research Board 105th Annual Meeting. Washington, DC. 2026.
- Maia, R.S., Regmi, B., & Hajj, R. "Toward a better understanding of the fatigue behavior of asphalt concrete with recycled materials at low strain levels." In Transportation Research Board 104th Annual Meeting. Washington, DC. 2025.
- Lu, Y., Maia, R.S., & Hajj, R. "Backcalculation of Asphalt Concrete Poisson's Ratio using the Ultrasonic Pulse Velocity Test." In Transportation Research Board 103rd Annual Meeting. Washington, DC. 2024.
- Asadi, B. & Hajj, R. "Development of Rubberized Asphalt Concrete Mix for Use as an Under Tie Pad Alternative in Railroad Applications." In Transportation Research Board 101st Annual Meeting. Washington, DC. 2022.
Invited Lectures
- Performance of bio-asphalt from hydrothermal liquefaction and biochar from mass pyrolysis in asphalt mixtures
- PCNet: Predicting asphalt binder mechanical properties from fractured surface images
- Next Generation Asphalt Materials and Pavements Research at UIUC
- Self-Healing Asphalt Capsule Design Using Combined Experimental-Computational Approach
- Using Computer Vision to Better Understand Porous Asphalt Degradation and Other Pavement Challenges
- Using AI to design the next generation of pavements
- Asphalt binder multi-scale studies and the future of pavement engineering and collaboration
- Multiscale characterization of viscoelastic construction materials using microscopic experiments and machine learning
- Leveraging materials science and machine learning to design the next generation of roads
Magazine Articles
- Hajj, Ramez. (2018) "Finding thinner strength: ultra thin overlays can have more muscle.'' Roads & Bridges, 2018, March: 42-46.
Reports
- El-Rayes, K., Ignacio, E.J., Hajj, R., Sallam, O., Al-Ghzawi, M., Hassan, A., & Almasry, O. Quantification of the Effectiveness and External Noise of Rumble Strip Designs. Final report for Illinois Department of Transportation Project R27-245HS. https://doi.org/10.36501/0197-9191/24-023
- Hajj, R. & Lu, Y. (2024). Assessment of the Impact of Unacceptable Hot-Mix Asphalt Test Parameters. Final report for Illinois Department of Transportation Project R27-SP59. https://doi.org/10.36501/0197-9191/24-012
- Hajj, R, Thompson, M., Maia, R.S., Lu, Y., Vyas, A., Asadi, B., & Regmi, B. (2024) Updates to Mechanistic-Empirical Design Inputs for Illinois Flexible Pavements. Final report for Illinois Department of Transportation Project R27-233. https://doi.org/10.36501/0197-9191/24-010
- Hajj, R., & Asadi, B. (2023) Review of Illinois Multiple Stress Creep and Recovery Data for Future Implementation. Final report for Illinois Department of Transportation Project R27-SP63. https://doi.org/10.36501/0197-9191/23-027
- Sayeh, W., Al-Qadi, I., & Hajj, R. (2023). Utilizing Reclaimed Asphalt Pavement in Preservation Treatments. Final report for Illinois Department of Transportation Project R27-SP56. https://doi.org/10.36501/0197-9191/23-022
- El-Rayes, K., Ignacio, E. J., Hajj, R., Sallam, O., & Al-Ghzawi, M. (2023). Noise measurements of US-41 transverse rumble strips. Part I of report for Illinois Department of Transportation Project R27-245-HS. https://doi.org/10.36501/0197-9191/23-004
- Hajj, R., Garg, N., Doehring, J., Vyas, A., Asadi, B., & Lu, Y. (2023) Using microcapsules and bacteria for self-healing in rigid and flexible pavements. Final report for Illinois Autonomous and Connected Track research project 21-03. https://doi.org/10.36501/0197-9191/23-001
- Thompson, M. R., & Hajj, R. (2021). Flexible pavement recycling techniques: a summary of activities. Final report for Illinois Department of Transportation Project R27-193-1. https://doi.org/10.36501/0197-9191/21-022
- Hajj, R., & Lu, Y. (2021). Current and future best practices for pothole repair in Illinois. Final report for Illinois Department of Transportation Project R27-SP44. https://doi.org/10.36501/0197-9191/21-003
- Filonzi, A., Lee, S. K., Hajj, R., Hazlett, D., & Bhasin, A. (2020). Implementing revisions to the allowable maximum Recycled Binder Ratio (RBR) specification. Final report for Texas Department of Transportation Project 0-6947.
- Hajj, R., Filonzi, A., & Bhasin, A. (2019). Improving the performance-graded asphalt binder specification (No. FHWA/TX-18/0-6925-1). Final report for Texas Department of Transportation Project 0-6925.
- Filonzi, A., Sabaraya, I. V., Hajj, R., Das, D., Saleh, N. B., & Bhasin, A. (2018). Evaluating the use of nanomaterials to enhance properties of asphalt binders and mixtures. Final report for Texas Department of Transportation Project 0-6854.
- Hajj, R., Filonzi, A., Bhasin, A., Dormohammadi, A., Zhu, C., & Tandon, V. (2018). Design and construction of ultra thin overlays as an alternative to seal coats. Final report for Texas Department of Transportation Project 0-6857.
Honors
- Outstanding Academic Member, Academy of Pavement Science and Engineering (2026)
- llinois Asphalt Pavement Association (IAPA) Bituminous Innovative Research Award (2025)
- Outstanding Reviewer, Journal of Transportation Engineering Part B: Pavements (2022)
- Outstanding Reviewer, Journal of Materials in Civil Engineering (2021 )
Teaching Honors
- List of Teachers Ranked as Excellent, CEE 405, Center for Innovation in Teaching and Learning (Fall 2023)
- Levenick Teaching Sustainability Fellowship, Institute for Sustainability, Energy, and Environment (2021 - 2022)
- List of Teachers Ranked as Excellent, CEE 405, Center for Innovation in Teaching and Learning (The instructor ratings were outstanding) (Fall 2021 )
- List of Teachers Ranked as Excellent, CEE 310, Center for Innovation in Teaching and Learning (Spring 2021)
- List of Teachers Ranked as Excellent, CEE 506, Center for Innovation in Teaching and Learning (The instructor ratings were outstanding) (Spring 2021)
- List of Teachers Ranked as Excellent, CEE 405, Center for Innovation in Teaching and Learning (Fall 2020 )
Research Honors
- llinois Asphalt Pavement Association (IAPA) Bituminous Innovative Research Award (2025)
- Faculty Fellow, Illinois-Indiana Sea Grant (2021)