Date of Graduation

8-2022

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering (MSCE)

Degree Level

Graduate

Department

Civil Engineering

Advisor/Mentor

Kevin Hall

Committee Member

Andrew F. Braham

Second Committee Member

Michelle Lee Barry

Keywords

Materials Properties, Pavement Design, asphalt binder

Abstract

The most common distresses in asphalt pavement are cracking and rutting. These distresses plague almost every asphalt roadway in the world. Finding ways to mitigate these distresses will improve the performance of asphalt pavements. One way to combat the premature cracking of asphalt in the field is to ensure there is enough asphalt binder within the mix. This will help the flexibility of the asphalt undergoing large loads and deformation. However, it is widely accepted that mix designs across the country lack the appropriate amount of asphalt binder in their mixes, causing dry mix designs that are subject to cracking before their intended design life has expired. Twenty-seven states across the United States have lowered the number of design gyration requirements to encourage the design of mixes with a slightly higher binder content. Arkansas is not one of those states. Therefore, this research investigating the performance of lower design gyrations for Arkansas asphalt mix designs is the initial exploration and proof of concept for Arkansas. By comparing the cracking tolerance index (〖CT〗_Index) of field cores, plant-mixed lab-compacted, and lab-mixed lab-compacted samples, numerous conclusions can be drawn, and further research can be developed. This study tested field cores and plant mixed lab compacted samples for four different mix designs, two with recycled asphalt concrete (RAP) and two without, from four different asphalt plants in Arkansas. Two of those mix designs, one with RAP and one without, were selected to be evaluated using lab-mixed lab-compacted samples as well. The results of this study showed that field cores, in general, performed with a higher cracking tolerance over plant-mixed lab-compacted and lab-mixed lab-compacted samples. The lab-mixed lab-compacted samples outperformed the plant-mixed lab-compacted samples in both instances they were tested, verified by a paired t-test. This study serves well as a basis for future studies on the reduction of gyrations for Arkansas asphalt mix designs.

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