Investigation on the durability of OGFC-5 ultra-thin friction course with different mixes

Abstract The ultra-thin friction course is one of the most effective treatments in highway preventive maintenances, but insufficient durability of mixtures seriously restricts the service life of ultra-thin friction course. This paper investigated the durability of Open-Graded Friction Course (OGFC)-5 ultra-thin friction course mixtures with different gradations and asphalt contents. Performances of raveling resistance, moisture susceptibility, rutting resistance, stripping resistance, and fracture resistance were evaluated by Cantabro test, Hamburg wheel tracking (HWT) test, and Indirect Tensile Asphalt Cracking Test (IDEAL-CT), respectively. The Pearson’s correlation analysis between durability indicators and air voids as well as asphalt film thickness were also conducted. The results showed that mixtures with denser gradation exhibited better raveling resistance and relatively enhanced moisture susceptibility. However, the denser gradation would decrease the rutting resistance and stripping resistance of mixtures, as well as increase the fracture propagation rate, thus a reduced fracture resistance performance. Increasing asphalt content could improve the performance of resistance to raveling, moisture damage, stripping, and fracture. Higher asphalt content also enhanced the rutting resistance of mixtures while the asphalt content was not recommended to be extremely high. Results of Pearson correlation analysis showed that the smaller air voids and asphalt film thickness could result a better raveling resistance and moisture susceptibility performance of OGFC-5 mixtures. However, for the performance of resistance to rutting, stripping and fracture, the larger air voids and asphalt film thickness were required. Therefore, during the design process of OGFC-5 ultra-thin friction course mixtures, the air voids and asphalt film thickness should be determined in combination with the concerned performance.