Design, Construction, and Early Performance of Hot-mix Asphalt Stabilizer and Modifier Test Sections

About the report:

This study evaluated three modifiers and two types of fibers (stabilizers) commonly available in Virginia for hot-mix asphalt (HMA). Ten test sections were built in 1995 on I-66 west of Manassas, Virginia. The modified asphalts complied with the specifications for performance grade (PG) 76-22. They were placed in both dense-graded Marshall and coarse-graded Superpave mixtures. The fibers were placed only in the dense-graded Marshall mixtures. During the design process, the dense-graded Marshall mixture complied with all of the Superpave requirements with the exception of the gradation, which passed through the restricted zone. Samples from the sections were tested for asphalt content, gradation, and Superpave and Marshall volumetrics and then rut tested using the Georgia loaded-wheel tester and the asphalt pavement analyzer. Field samples generally passed Marshall volumetrics and generally failed Superpave volumetrics. Neither laboratory compaction method correlated with the ultimate field densities. All of the sections are rut resistant and have performed well after 45 months of service in the field.

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