CPII Road and Pavement Inspection 5 — Questions and Answers
Question 1: Which pavement surface treatment involves applying a thin polymer-modified asphalt slurry with aggregate to seal and improve friction on an existing pavement?
- Fog seal
- Slurry seal
- Microsurfacing (Correct answer)
- Cape seal
Correct answer: Microsurfacing
Microsurfacing uses polymer-modified binder and well-graded aggregate mixed on-site; unlike slurry seal, it can be opened to traffic quickly and used to fill ruts.
Question 2: A longitudinal crack located in the wheel path of an asphalt pavement is most likely caused by:
- Reflection from a joint in the underlying base
- Fatigue from repeated traffic loading causing shear failure (Correct answer)
- Thermal expansion and contraction
- Construction cold joint from paving in separate passes
Correct answer: Fatigue from repeated traffic loading causing shear failure
Wheel-path longitudinal cracks outside the joint area indicate fatigue or shear failure from repeated loading on a pavement with insufficient structural capacity.
Question 3: Which test method is used to measure the in-place density of compacted asphalt pavement during construction inspection?
- Sand cone method (ASTM D1556)
- Nuclear density gauge (ASTM D2950) (Correct answer)
- Proctor test (ASTM D698)
- Plate load test (ASTM D1196)
Correct answer: Nuclear density gauge (ASTM D2950)
The nuclear density gauge is the most common field method for measuring asphalt compaction by measuring gamma radiation attenuation through the pavement.
Question 4: What does 'map cracking' (crazing) in a concrete pavement slab indicate?
- Structural overloading from heavy trucks
- Surface shrinkage, alkali-silica reaction, or freeze-thaw damage limited to the slab surface (Correct answer)
- Voids beneath the slab from erosion of base material
- Transverse joint load transfer failure
Correct answer: Surface shrinkage, alkali-silica reaction, or freeze-thaw damage limited to the slab surface
Map cracking features random, interconnected surface cracks and typically results from surface shrinkage during curing, ASR, or freeze-thaw expansion limited to the top layer.
Question 5: When inspecting pavement joint seals on a concrete road, which condition warrants immediate sealant replacement?
- Sealant is slightly below flush with the pavement surface
- Sealant is missing or has separated from joint walls allowing debris intrusion (Correct answer)
- Sealant surface shows minor surface oxidation
- Sealant color has faded from original black
Correct answer: Sealant is missing or has separated from joint walls allowing debris intrusion
Missing or debonded joint sealant allows incompressible debris to fill joints, causing joint spalling and blowups during thermal expansion.
Question 6: The 'distress density' value used in PCI calculation is defined as:
- The number of distress occurrences per lane mile
- The total distress quantity divided by the sample unit area, expressed as a percentage (Correct answer)
- The ratio of cracked area to uncracked area only
- The average severity level weighted by area
Correct answer: The total distress quantity divided by the sample unit area, expressed as a percentage
Distress density (%) = (total distress quantity in the sample unit / sample unit area) × 100, and is used with severity to determine the deduct value.
Question 7: Which sign is a pavement inspector most likely to note as evidence of base course failure beneath flexible pavement?
- Transverse thermal cracking in isolated locations
- Pumping of fines through cracks under traffic loads (Correct answer)
- Longitudinal cracking along the centerline joint
- Surface raveling near the pavement edge
Correct answer: Pumping of fines through cracks under traffic loads
Pumping occurs when water-saturated fine material is ejected through pavement cracks under wheel loads, signaling base or subgrade saturation and failure.
CPII Road and Pavement Inspection 5
Which pavement surface treatment involves applying a thin polymer-modified asphalt slurry with aggregate to seal and improve friction on an existing pavement?