Early Characterization and Performance of Flexible Pavements Utilizing Asphalt Additives

Abstract

Asphalt additives have been utilized for years to modify the performance of flexible pavements. They have the potential to lead to long-lasting and sustainable asphalt pavements. In recent years, several new categories of asphalt additives, such as recycled tire rubber, post-consumer recycled plastic, and synthetic fiber, have been introduced to the flexible pavement industry. These new additives are being marketed toward agencies and contractors increasingly with the potential of increased pavement performance or maintaining performance at reduced cost. Field testing, which can confirm or deny the claimed benefits, is costly and time consuming. With the rapidly advancing asphalt additive industry, there is a need to efficiently evaluate and deploy the new asphalt additive technologies. To address this need, the National Center for Asphalt Technology developed the Additive Group Experiment for the 2021 NCAT Test Track research cycle to evaluate a range of new asphalt additive technologies. Full-scale pavement sections, each using a different asphalt additive, were constructed and instrumented at the Test Track. A primary objective of this thesis was to document the construction of these sections. Accelerated trafficking and monitoring of the sections then commenced. The data collected from the monitoring and testing of the sections was then used to achieve the secondary objective: preliminary surface performance evaluations and structural behavior characterizations. The performance and behavior of the additive modified sections were then compared to those of the control section. It was determined that the data analyzed for the relatively short timeframe did not allow for recommendations to be made in this thesis on the viability of the additives for use in real-world paving applications. It was recommended, however, to continue trafficking and field testing of the sections to more comprehensively characterize their performance and behavior.