NETTCP Material Specifications 5 — Questions and Answers
Question 1: Which test method is used to determine the flat and elongated particle content of coarse aggregate per ASTM D4791?
- A proportional caliper device measuring length, width, and thickness (Correct answer)
- Dry sieving through square-hole sieves
- Washing and decantation
- The Los Angeles abrasion machine
Correct answer: A proportional caliper device measuring length, width, and thickness
ASTM D4791 uses a proportional caliper to measure individual particle dimensions and classify particles as flat, elongated, or flat and elongated.
Question 2: In NETTCP-region DOT specifications, reclaimed asphalt pavement (RAP) used in hot mix asphalt is typically limited to what maximum percentage in surface courses?
- 25% (Correct answer)
- 10%
- 40%
- 50%
Correct answer: 25%
Most New England DOTs limit RAP content to approximately 25% in surface courses to maintain mixture performance and workability.
Question 3: What property of bituminous tack coat material is specified to ensure adequate bonding between pavement layers?
- Residual asphalt application rate after emulsion breaks (Correct answer)
- Penetration value at 25°C
- Flash point temperature
- Kinematic viscosity at 135°C
Correct answer: Residual asphalt application rate after emulsion breaks
Tack coat specifications focus on the residual asphalt application rate (typically 0.02–0.10 gal/yd²) after the emulsion water evaporates and the binder breaks.
Question 4: Precast concrete drainage pipe must meet which ASTM standard for reinforced concrete culvert pipe?
- ASTM C76 (Correct answer)
- ASTM C14
- ASTM C118
- ASTM C412
Correct answer: ASTM C76
ASTM C76 is the standard specification for reinforced concrete culvert, storm drain, and sewer pipe used in highway drainage.
Question 5: For high-density polyethylene (HDPE) drainage pipe used in highway culverts, which AASHTO material specification applies?
- AASHTO M 294 (Correct answer)
- AASHTO M 252
- AASHTO M 278
- AASHTO M 304
Correct answer: AASHTO M 294
AASHTO M 294 covers corrugated polyethylene pipe for use in subsurface drainage and storm sewers under highways.
Question 6: What does the term 'gradation envelope' refer to in aggregate specifications?
- The range of allowable percent passing values at each sieve size (Correct answer)
- The shape of aggregate particles measured by caliper
- The temperature range for hot mix asphalt compaction
- The moisture content limits for subgrade preparation
Correct answer: The range of allowable percent passing values at each sieve size
A gradation envelope defines the upper and lower limits of percent passing at each sieve size, within which the aggregate must fall to be accepted.
Question 7: Which AASHTO specification covers the requirements for liquid anti-stripping additives used in asphalt mixtures to improve aggregate-binder adhesion?
- AASHTO M 316 (Correct answer)
- AASHTO M 320
- AASHTO T 283
- AASHTO R 35
Correct answer: AASHTO M 316
AASHTO M 316 specifies requirements for liquid anti-stripping agents (chemical adhesion promoters) added to asphalt binders to improve moisture resistance.
NETTCP Material Specifications 5
Which test method is used to determine the flat and elongated particle content of coarse aggregate per ASTM D4791?