CPII Materials & Testing 4 — Questions and Answers
Question 1: What does the 'W' designation in a W8x31 structural steel section describe?
- Wide-flange section with approximately 8-inch depth and 31 lb/ft weight (Correct answer)
- Web thickness of 8 mm and 31 ksi yield strength
- Width of 8 inches and 31-inch depth
- Weld size of 8/16 inch and 31% efficiency
Correct answer: Wide-flange section with approximately 8-inch depth and 31 lb/ft weight
W-shapes are wide-flange sections; W8x31 means approximately 8 inches deep and weighing 31 pounds per linear foot.
Question 2: ASTM A325 and A490 bolts are primarily used in which type of structural connections?
- Concrete anchor bolts
- High-strength structural steel connections (Correct answer)
- Timber framing connections
- Masonry ties
Correct answer: High-strength structural steel connections
A325 and A490 are high-strength bolts used in structural steel moment and shear connections.
Question 3: During concrete placement, what condition causes 'cold joints'?
- Concrete placed in cold weather below 40°F
- A delay between successive concrete placements allowing the first lift to harden before the next is placed (Correct answer)
- Adding too much water to the mix
- Rapid cooling of concrete after placement
Correct answer: A delay between successive concrete placements allowing the first lift to harden before the next is placed
Cold joints form when concrete in a previous lift stiffens before the next lift is placed, preventing proper bonding between layers.
Question 4: What is the purpose of performing a wash gradation (wet sieve analysis) instead of a dry sieve analysis?
- To determine moisture content
- To remove dust and fine particles clinging to larger aggregate particles for accurate gradation (Correct answer)
- To measure aggregate absorption
- To separate lightweight particles
Correct answer: To remove dust and fine particles clinging to larger aggregate particles for accurate gradation
Washing the aggregate before sieving removes dust and fine material coating particle surfaces, giving a more accurate size distribution.
Question 5: Which test measures the resistance of asphalt mixtures to permanent deformation (rutting)?
- Marshall stability test (Correct answer)
- Ductility test
- Penetration test
- Flash point test
Correct answer: Marshall stability test
The Marshall stability test measures the load resistance of a compacted asphalt mix at 140°F, indicating rut resistance.
Question 6: When inspecting reinforced concrete construction, what is the minimum concrete cover required for reinforcement in a concrete bridge deck exposed to deicing salts per AASHTO?
- 1 inch
- 1.5 inches
- 2.5 inches (Correct answer)
- 3 inches
Correct answer: 2.5 inches
AASHTO requires a minimum of 2.5 inches of clear cover for reinforcement in bridge decks exposed to deicing chemicals.
Question 7: A field density test result for a soil embankment shows 92% compaction where 95% is required. What is the correct course of action?
- Accept the work if average of all tests meets 95%
- Reject the work and require additional compaction passes in the failing area (Correct answer)
- Add water to the failing area to raise density
- Increase the proctor test standard to match field conditions
Correct answer: Reject the work and require additional compaction passes in the failing area
Failing areas must be reworked with additional compaction equipment passes until they meet the specified minimum compaction requirement.
CPII Materials & Testing 4
What does the 'W' designation in a W8x31 structural steel section describe?