Analysis of aramid synthetic fibers in asphalt mixes on local roads

"June 2021."; "Prepared for: Ohio's Research Initiative for Locals, The Ohio Department of Transportation, Office of Statewide Planning & Research"--PDF cover; Includes bibliographical references; Final report; Sponsored by Ohio Department of Transportation, Office of Statewide Planning & Research ; PID number: 109988 ; SJN: 136006Final report (134 variously numbered pages) -- [Fact sheet] (2 unnumbered pages)This report summarizes the results of a research project that was conducted to evaluate the cracking resistance of aramid fiber-reinforced asphalt mixes used for resurfacing applications on local roads and compare it to that of polymer-modified asphalt mixes. This project was divided into two phases. Based on the results of laboratory study in Phase 1, fifteen test sections were constructed during 2020 construction season as part of five projects in the City of Columbus, Fayette County, and the City of Kettering. Two aramid fiber types, one with 0.75 in. (Fiber B) and the other 1.5 in. length (Fiber A) from different sources, were used for this project. During the construction of the test sections, loose asphalt mixtures and field cores were collected for evaluation in the laboratory using semi-circular bend (SCB), indirect tensile asphalt cracking test (IDEAL-CT), and asphalt concrete cracking device (ACCD). The results of laboratory tests conducted on field cores and field-produced laboratory compacted samples indicated that the effects of addition of aramid fiber to asphalt mixture vary depending on binder grade, binder type, and mix type. In general, Fiber A and Fiber B improved the cracking resistance of mixes with PG 64-22. Mixes with PG 64-22 binder and aramid fibers had similar cracking resistance to those with PG 70-22M asphalt mix. Fiber A improved the cracking resistance for mixes with PG 58-28 binder. In addition, Fiber B improved the indirect tensile strength for mixes with PG 58-28 and had similar cracking resistance as those with PG 64-22. The fibers did not improve the low-temperature cracking resistance of asphalt mixes. The statistical analysis of the test results indicated that the properties related to the cracking resistance of the fiber mixes did not significantly change during the different production day