Relative to the adjacent lift, how should the height of the loose lift be positioned?

• A. Lower than adjacent
• B. Equal to adjacent
• C. Higher than adjacent
• D. Varies with temperature

Answer: (C)

The loose lift should be placed slightly higher than the adjacent lift. As asphalt is compacted, it densifies and its thickness decreases, so starting with a loose layer that sits a bit high ensures the finished surface ends up at the correct grade. If it were placed at the same height or lower, compaction would leave a surface that’s low at the joint. Temperature can affect workability, but the standard practice is to overbuild a little to account for compaction, not to vary height with temperature.