Lift Thickness & Surface Tolerance Flashcards
7 cards from real PIC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Lift Thickness & Surface Tolerance flashcards as text
A contractor places a base course lift measuring 4.2 inches compacted when the specification requires 4.0 inches maximum. What is the inspector's appropriate action?
Answer: Reject the lift for exceeding the maximum thickness tolerance
Maximum lift thickness specifications exist to ensure proper compaction throughout the depth, and exceeding them is a contractual non-conformance requiring rejection or corrective action.
What tool is most commonly used to verify compacted lift thickness in the field?
Answer: Pin probe or depth gauge inserted through the mat
A pin probe or depth gauge inserted through the freshly compacted mat directly measures lift thickness at the point of placement.
Surface tolerance for a finished wearing course on an interstate highway is typically measured with a how-long straightedge?
Answer: 10-foot
A 10-foot straightedge is the standard reference length used to check surface smoothness and tolerance on most state DOT specifications for wearing courses.
When compacting multiple thin lifts instead of one thicker lift, the primary disadvantage is:
Answer: Increased risk of tender zone behavior in each lift
Multiple thin lifts cool faster, increasing tender zone risk where the mix is susceptible to shoving under roller load before it stiffens.
A specification allows a surface tolerance of ±0.01 foot from design grade. A measured elevation is 0.013 foot below design grade. The inspector should:
Answer: Flag the area as out of tolerance and document it
A reading of 0.013 foot exceeds the ±0.01 foot (±0.12 inch) allowable deviation and must be flagged as out of tolerance per specification.
Which factor most significantly affects the required loose lift thickness before compaction?
Answer: Expected compaction ratio of the mix
The compaction ratio (ratio of loose to compacted thickness, typically 1.15–1.35) determines how thick the loose mat must be placed to achieve the specified compacted thickness.
On a resurfacing project, the existing pavement surface has a measured rut depth of 1.5 inches. If specification requires final surface tolerance of ±0.25 inch, the leveling course strategy must:
Answer: Use variable-depth leveling passes to fill ruts before wearing course
Rutted surfaces require variable-depth leveling lifts that fill low spots first so the wearing course can be placed at uniform thickness and meet surface tolerance.