NETTCP Material Specifications 3 — Questions and Answers
Question 1: In New England state DOT specifications, what is the maximum sodium sulfate soundness loss typically permitted for coarse aggregate used in pavement surface courses?
- 12% (Correct answer)
- 5%
- 18%
- 25%
Correct answer: 12%
Most New England DOT specifications limit sodium sulfate soundness loss to 12% for coarse aggregate in pavement surface courses to ensure freeze-thaw durability.
Question 2: Which ASTM designation governs the specification for deformed and plain steel bars for concrete reinforcement (rebar)?
- ASTM A615 (Correct answer)
- ASTM A36
- ASTM A706
- ASTM A307
Correct answer: ASTM A615
ASTM A615 is the standard specification for deformed and plain carbon-steel bars used as concrete reinforcement.
Question 3: For corrugated metal pipe (CMP) used in drainage culverts, what property is specified by AASHTO M 36?
- Corrugated steel pipe dimensions, coating, and wall thickness (Correct answer)
- Minimum compressive ring strength
- Maximum allowable deflection under load
- Hydraulic flow coefficients
Correct answer: Corrugated steel pipe dimensions, coating, and wall thickness
AASHTO M 36 specifies the dimensions, wall thickness, corrugation profile, and coating requirements for corrugated steel pipe.
Question 4: What is the minimum California Bearing Ratio (CBR) typically required for subbase material per AASHTO specifications?
- 20% (Correct answer)
- 10%
- 5%
- 30%
Correct answer: 20%
AASHTO typically requires a minimum CBR of 20% for granular subbase material to provide adequate support for the pavement structure.
Question 5: Epoxy-coated reinforcing bars used in bridge decks must meet which ASTM specification?
- ASTM A775 (Correct answer)
- ASTM A934
- ASTM A820
- ASTM A1064
Correct answer: ASTM A775
ASTM A775 covers epoxy-coated steel reinforcing bars where the coating is applied after fabrication of the bar.
Question 6: In the context of highway paint markings, which retroreflectivity standard is referenced in AASHTO specifications for new pavement markings?
- ASTM E1710 (Correct answer)
- ASTM D711
- AASHTO T 255
- ASTM D476
Correct answer: ASTM E1710
ASTM E1710 is the standard test method for measuring retroreflectivity of pavement markings using a portable retroreflectometer.
Question 7: What aggregate property is determined by AASHTO T 84 and T 85?
- Specific gravity and absorption of fine and coarse aggregate respectively (Correct answer)
- Gradation of combined aggregates
- Flat and elongated particle ratios
- Organic impurity content of sand
Correct answer: Specific gravity and absorption of fine and coarse aggregate respectively
AASHTO T 84 measures specific gravity and absorption of fine aggregate, while T 85 covers coarse aggregate.
NETTCP Material Specifications 3
In New England state DOT specifications, what is the maximum sodium sulfate soundness loss typically permitted for coarse aggregate used in pavement surface courses?