PIC Inspection Standards & Quality Control 3 — Questions and Answers
Question 1: What is the acceptable range for asphalt content deviation from the JMF target under most AASHTO/state DOT specifications?
- ±0.1%
- ±0.3%
- ±0.5% (Correct answer)
- ±1.0%
Correct answer: ±0.5%
Most state DOT specifications allow asphalt binder content to deviate no more than ±0.5% from the JMF target during plant production.
Question 2: When inspecting a longitudinal joint between two adjacent HMA lanes, which condition is most indicative of a quality joint?
- Visible aggregate exposed along the joint line
- A slight hump of 0.5 inches above the adjacent lane
- Density matching the adjacent mat within specification (Correct answer)
- A distinct color difference between the two lanes
Correct answer: Density matching the adjacent mat within specification
A quality longitudinal joint is characterized by density comparable to the adjacent mat, ensuring structural continuity and resistance to moisture infiltration.
Question 3: Under ASTM D3549, what is the standard method for measuring the thickness of bituminous pavement cores?
- Ultrasonic pulse velocity measurement
- Digital caliper measurement at three equidistant points averaged (Correct answer)
- Steel rule measurement at the thinnest point only
- GPR scanning of the extracted core
Correct answer: Digital caliper measurement at three equidistant points averaged
ASTM D3549 specifies that core thickness be measured with a caliper at three equidistant points around the core perimeter and the values averaged.
Question 4: A contractor claims a failing density lot should be accepted based on individual test results rather than the lot average. Which principle of statistical quality control does the inspector cite to refute this?
- The central limit theorem
- Lot-by-lot acceptance testing (Correct answer)
- The range control chart method
- Stratified random sampling
Correct answer: Lot-by-lot acceptance testing
Lot-by-lot acceptance testing evaluates the lot as a whole using the mean of sample results, not individual outlier tests, to determine acceptance or rejection.
Question 5: Which in-place permeability test method is used to assess the potential for water infiltration through a completed asphalt pavement surface?
- Florida field permeameter test (Correct answer)
- Modified Proctor compaction test
- Marshall stability flow test
- Hveem cohesiometer test
Correct answer: Florida field permeameter test
The Florida field permeameter measures the rate of water infiltration through a compacted asphalt surface to evaluate permeability and potential for moisture damage.
Question 6: An inspector observes that the HMA delivery tickets show consistent plant mix temperatures around 290°F but the in-place mat temperature before rolling is only 230°F. What is the most likely cause?
- Incorrect thermometer calibration at the plant
- Excessive haul time or inadequate truck covers during transport (Correct answer)
- Overcompaction by the breakdown roller
- Insufficient tack coat application rate
Correct answer: Excessive haul time or inadequate truck covers during transport
A significant temperature drop from plant to mat typically results from long haul distances or trucks lacking protective covers, causing rapid heat loss during transport.
Question 7: Which specification section most commonly defines the required number of random core locations per lot for density acceptance testing?
- The soils and aggregate section
- The traffic control plan
- The special provisions or standard specifications for HMA (Correct answer)
- The environmental mitigation plan
Correct answer: The special provisions or standard specifications for HMA
The number and location of cores required for density acceptance are defined in the project's special provisions or the agency's standard specifications for hot mix asphalt.
PIC Inspection Standards & Quality Control 3
What is the acceptable range for asphalt content deviation from the JMF target under most AASHTO/state DOT specifications?