EAS Doctoral Dissertation Defense by Mazen Kandil
CIE – Main Conference Room (Room 4A)
Commonwealth Professor Walaa St. Mogawer
wmogawer@umassd.edu
Topic: Enhancing the Performance, Safety, and Longevity of Massachusetts Pavements: Superpave5, Crowdsourced Friction, Profiler Certification, and Friction-Integrated Balanced Mix Design
Abstract:
This dissertation is aimed to help the Massachusetts Department of Transportation (MassDOT) improve pavement durability, safety, and performance by addressing four needs: improving in-place density through mixture design, evaluating emerging technologies for continuous friction monitoring, improving the reliability of smoothness measurements used for construction acceptance, and incorporating surface characteristics into balanced mix design (BMD). The first study evaluated Superpave5 (SP5) as an alternative to MassDOT's current Superpave4 (SP4) methodology, which has struggled to consistently achieve MassDOT’s required 95% in-place density despite increased voids in mineral aggregate (VMA) requirements. SP5 mixtures designed at 5% air voids with reduced gyrations were developed using two Massachusetts aggregate sources and compared with SP4 mixtures. SP5 demonstrated improved compactibility and workability while meeting MassDOT's Hamburg Wheel Tracking Test rutting criteria. Results showed that cracking performance depended more on material source than design methodology, permeability remained acceptable, and FlexPAVE™ simulations predicted reduced long-term rutting for SP5 mixtures. These findings support SP5 implementation without MassDOT's additional VMA requirement. The second study assessed an emerging crowdsourced vehicle friction measurement (CVFM) technology against MassDOT's ASTM E274 locked-wheel skid trailer (LWST). CVFM estimates tire– pavement friction using vehicle sensors and multiple estimation modules representing different driving conditions. Measurements using both methods along Interstates 90 and 95 during a January 2026 winter storm yielded 126 spatially matched pairs. Overall, CVFM readings averaged approximately two skid numbers higher than LWST measurements, a statistically significant but practically small difference. Narrowing the analysis down to the traction control system (TCS) module, which generated most matched pairs, demonstrated statistical equivalence within ASTM E274 precision limits. Results support CVFM for winter operations and network-level friction screening as a complement to LWST. The third study evaluated the practicality of the profiler certification thresholds in AASHTO R 56-25 using five years of Massachusetts certification data. AASHTO R 56-25 requires inertial profilers to achieve 92% repeatability and 90% accuracy relative to a reference device. The repeatability threshold yielded an average passing rate of 82.5%, while the accuracy threshold yielded only 39.2%, indicating that the accuracy requirement may be overly restrictive. Statistical analysis showed that reducing the accuracy threshold to 84% would raise the average passing rate to 73.3%. In addition, an absolute International Roughness Index (IRI) deviation limit of ±5 in./mi produced consistent passing rates of 82-83% across smooth and medium smooth sections. The final study developed a conceptual framework for incorporating friction into BMD. Two mixtures from the National Center for Asphalt Technology (NCAT) test track met rutting and cracking criteria but exhibited substantially different field friction, demonstrating the need to include surface characteristics in BMD. Laboratory testing on gyratory-compacted circular specimens from the same mixtures, Three-Wheel Polishing Device, Dynamic Friction Tester and British Pendulum successfully characterized initial friction and polished friction, reproducing similar field friction ranking of both mixtures. Collectively, this research provides MassDOT with implementable approaches to improve pavement durability through SP5, enhance roadway safety through continuous friction monitoring and friction-integrated BMD, and improve smoothness acceptance through practical profiler certification criteria.
ADVISOR(S):
Commonwealth Professor Walaa St. Mogawer, P.E. Department of Civil & Environmental Engineering (wmogawer@umassd.edu)
COMMITTEE MEMBERS:
- Dr. Raymon Bonaquist, P.E., Advanced Asphalt Technologies
- Professor Benjamin Shane Underwood, Civil & Environmental Engineering, N.C State University
- Professor Daniel MacDonald, Department of Civil & Environmental Engineering
- Professor Mazdak Tootkaboni, Department of Civil & Environmental Engineering
NOTE: All EAS Students are ENCOURAGED to attend.