Semester of Graduation

Spring 2024


Master of Science in Civil Engineering (MSCE)


Department of Civil and Environmental Engineering

Document Type



Achieving long-term durability and sustainability in flexible pavement is a significant concern in highway infrastructure construction. State highway agencies (SHAs) have implemented various enhanced asphalt mixture design methods and construction practices to address this concern. With advancements in improved asphalt mixture design and construction practices, it is imperative to evaluate the long-term field performance of pavements. Therefore, this study assessed the long-term field performance of flexible pavements in Louisiana, considering enhanced asphalt mixture design methods and construction techniques.

The study consisted of two main sections. In the first section, the field performance of two projects was evaluated: asphalt mixture pavement sections containing crumb rubber (CR) particles as component materials and asphalt pavement sections constructed utilizing the Louisiana DOTD-specified balanced mix design (BMD) approach. The field performance of these projects was assessed to determine the effects of CR additives on long-term performance and to validate the laboratory rutting and cracking performance thresholds specified in the Louisiana BMD framework. In the second section, enhanced construction methods, such as increased in-place density techniques and methods for enhancing the interlayer shear strength (ISS) of flexible pavement layers, were evaluated to assess their effects on performance. For increased in-place density techniques, pavement sections constructed using warm mix asphalt (WMA) additives, increased asphalt content above the optimum level, and temperature-segregation minimization techniques were evaluated to determine their effects on field in-place density and long-term performance. Additionally, pavements constructed using different tack coat materials at residual application rates ranging from 0.01 to 0.06 gallons per square yard (gsy) were evaluated to determine factors influencing ISS and to validate the minimum ISS criteria (40 psi) recommended in NCHRP project 9–40.

For each field project considered in this study, field performance data (rutting, roughness, and cracking) and overall pavement condition index (PCI) were collected and analyzed to determine the effects of enhanced mixture design methods and construction techniques. Laboratory performance data measured during construction were also obtained and analyzed to determine their ability to rank field performance. Additionally, a life-cycle cost analysis was conducted for the CR-modified pavement sections to evaluate their cost-effectiveness.



Committee Chair

Mohammad, Louay N.

Available for download on Sunday, January 26, 2025