UTC 2022 Funding - Cycle 2 Research Projects

Project Number: CY2-UTEP-02
Project Title: Refining Asphalt Mixture Fatigue Cracking Design Criteria Based on Overlay Testing
Performing Institution: University of Texas at El Paso
Principal Investigators: Miguel A. Montoya, Soheil Nazarian, and Rajib B. Mallick
Proposed Start and End Date: 10/01/24 to 09/30/25
Project Description: Improving fatigue characterization is essential for enhancing the durability and sustainability of asphalt mixtures, leading to increased road resilience, reduced maintenance costs, and minimized environmental impact. The Overlay Test (OT), a crucial method for assessing the susceptibility of asphalt mixtures to fatigue cracking, involves subjecting asphalt mixture specimens to repeated direct tension loads. The cracking susceptibility of a mix with OT is assessed based on performance indices, such as Critical Fracture Energy (CFE) and Crack Propagation Rate (CPR). The existing fatigue cracking criteria for developing a balanced mixture do not account for the aging of the mix and are based on testing minimally aged asphalt mixtures. As asphalt materials age, they become more brittle and less flexible, making pavements more susceptible to cracking and reducing their capacity for healing. Although past research has helped to calibrate OT testing factors (i.e., NCHRP 09-57), little attention has been given to refining design criteria at different aging levels. This research aims to establish criteria that consider the oxidation effect for asphalt mixture design using the OT method. The study will involve thorough data analysis to adjust threshold limits for CFE and CPR when evaluating aged asphalt mixture specimens and generate a research output that differentiates from past studies. The findings obtained from the data analysis will be validated through an experimental investigation. Lastly, recommendations will be provided to implement the research findings.
Click here to learn more