NETTCP Material Specifications 2 — Questions and Answers
Question 1: According to AASHTO M 43, what sieve size defines the boundary between fine and coarse aggregate?
- No. 4 (4.75 mm) (Correct answer)
- No. 8 (2.36 mm)
- No. 16 (1.18 mm)
- 3/8 inch (9.5 mm)
Correct answer: No. 4 (4.75 mm)
AASHTO M 43 defines the No. 4 (4.75 mm) sieve as the boundary between fine and coarse aggregate.
Question 2: Which AASHTO designation covers requirements for Superpave Performance-Graded (PG) asphalt binders?
- AASHTO M 320 (Correct answer)
- AASHTO M 226
- AASHTO T 240
- AASHTO M 17
Correct answer: AASHTO M 320
AASHTO M 320 specifies Performance-Graded asphalt binder requirements used in the Superpave system.
Question 3: What does the 'L' value in a PG 64-22 asphalt binder designation represent?
- The minimum pavement temperature in °C at which the binder must perform (Correct answer)
- The high-temperature performance grade in °C
- The viscosity grade at 135°C
- The penetration value at 25°C
Correct answer: The minimum pavement temperature in °C at which the binder must perform
In PG 64-22, the -22 represents the minimum pavement design temperature in degrees Celsius.
Question 4: For hot mix asphalt, which property of coarse aggregate is measured by AASHTO T 96 (Los Angeles Abrasion)?
- Resistance to degradation by abrasion and impact (Correct answer)
- Soundness under freeze-thaw cycling
- Flat and elongated particle content
- Specific gravity and absorption
Correct answer: Resistance to degradation by abrasion and impact
AASHTO T 96 measures aggregate resistance to degradation by abrasion and impact using the Los Angeles machine.
Question 5: Which type of portland cement is most commonly specified for general construction of transportation structures in New England?
- Type I/II (Correct answer)
- Type III
- Type IV
- Type V
Correct answer: Type I/II
Type I/II cement meets requirements for general use and moderate sulfate resistance, making it the standard choice for transportation construction.
Question 6: What minimum compressive strength at 28 days does AASHTO M 157 typically require for Class A bridge concrete?
- 4,000 psi (Correct answer)
- 2,500 psi
- 3,500 psi
- 5,000 psi
Correct answer: 4,000 psi
Class A bridge concrete typically requires a minimum 28-day compressive strength of 4,000 psi per AASHTO M 157 guidelines.
Question 7: When specifying geosynthetic reinforcement for mechanically stabilized earth (MSE) walls, which AASHTO standard applies?
- AASHTO M 288 (Correct answer)
- AASHTO M 145
- AASHTO M 196
- AASHTO M 252
Correct answer: AASHTO M 288
AASHTO M 288 covers geosynthetic specification for highway applications, including reinforcement for MSE walls.
NETTCP Material Specifications 2
According to AASHTO M 43, what sieve size defines the boundary between fine and coarse aggregate?