Air voids behind the paver typically range between which percentages?

• A. 0%-5%
• B. 10%-20%
• C. 20%-30%
• D. 5%-10%

Answer: (B)

Air voids behind the paver reflect how loose the asphalt mat is as it’s laid and before the rollers finish compacting it. The mat is deposited with a fair amount of air spaces, and rollers work to squeeze out some of those voids to reach the proper density. In practice, the loose mat behind the paver typically shows about 10 to 20 percent air voids. This range balances having enough openness for proper compaction and stability, while not being so loose that the mix can fault or drain excessively. The other ranges would indicate either too dense a loose mat or too open a mat, which doesn’t align with how the paving process behaves right after placement.