What is a consequence of using a thin lift that requires less HMA per square foot than a thick lift?

• A. Paver speed may increase, making it difficult for rollers to keep up.
• B. Compaction window becomes longer.
• C. Screed wear decreases.
• D. Mats tear less easily.

Answer: (A)

When a lift is thinner, you place less HMA per square foot, so the paver can move faster to cover the same area. That higher lay-down rate pushes the roller team to follow more quickly to compact the mat while it’s still workable. If rollers can’t keep up with the faster arrival of fresh material, compaction quality suffers, leading to density and surface issues. In addition, thinner lifts cool and stiffen more quickly, narrowing the window for proper compaction, which reinforces why keeping pace matters.

The other outcomes don’t directly follow from thinner lift thickness: the compaction window doesn’t lengthen (it tends to shorten with faster lay-down and quicker cooling), screed wear isn’t inherently reduced by thinner lifts, and mat tearing isn’t a guaranteed consequence of using a thinner lift.