01664293

Component

Open graded friction course (OGFC) and porous friction course (PFC) wearing surfaces are used by many transportation agencies in the US and around the world primarily to improve safety in wet weather. However, durability (i.e., raveling) of these mixtures has been an issue and a topic of study. The primary objective of this study was to study the influence of the LA abrasion value of the aggregate on the performance (raveling resistance and porosity) of the OGFC mixture in lab. This study evaluated OGFC mixtures made with 11 different aggregate sources having LA abrasion values ranging from 20 to 54. The results indicated that higher LA aggregate yielded more resistance to raveling. However, further study and analysis indicated that the aggregate particles fractured during mixing and compaction and the degree of aggregate breakdown was quantified by calculating the uniformity coefficient (Cᵤ) of compacted and uncompacted OGFC mix specimens. Aggregate breakdown resulted in the gradation changing to a finer, more well-graded aggregate distribution (higher Cᵤ) with a higher packing density, thus reducing the porosity, which increased performance in the Cantabro abrasion test. The results also indicated that compaction effort of 50 gyrations of the Superpave Gyratory Compactor resulted in breakdown that increased the Cᵤ by a factor of approximately 1.5 compared to the Cᵤ after mixing alone in the laboratory bucket mixer.

This paper was sponsored by TRB committee AFP70 Standing Committee on Aggregates.

18-06295

English

15p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; References; Tables

Abrasion tests; Aggregate gradation; Aggregate mixtures; Coefficients; Compaction; Deterioration; Friction course; Gyratory testing machines; Laboratory tests; Open graded aggregates; Pavement performance; Performance tests; Porosity; Stripping (Pavements)

Los Angeles Abrasion Test

South Carolina

Highways; Materials; Pavements; I30: Materials

Transportation Research Board Annual Meeting 2018 Paper #18-06295

TRIS, TRB, ATRI

Jan 8 2018 11:37AM