Voids filled with asphalt, the percentage of VMA that holds effective binder, calculated as VMA minus air voids, divided by VMA. It ties the other two volumetric numbers together: high VFA means a rich mix at risk of bleeding and rutting, low VFA means thin binder films and poor durability. Superpave limits fall around 65 to 75 percent for heavy traffic, with higher ranges allowed on low-volume roads.
Voids and VMA both look fine but VFA's at 79, it's going to be right on the edge of flushing come July.
Also heard as
- voids filled with asphalt
Related terms
VMA
Voids in mineral aggregate: the space between aggregate particles available for binder and air.
Air voids
The small pockets of air between binder-coated aggregate in compacted mix, given as a percent of total volume.
Bleeding
Free binder rising to the pavement surface, leaving shiny, sticky black patches that turn slick when wet.