CPC CPC Construction Methods & Materials 1 — Questions and Answers
Question 1: Which concrete curing method involves covering freshly placed concrete with wet burlap or curing blankets?
- Membrane curing
- Wet curing (Correct answer)
- Steam curing
- Chemical curing
Correct answer: Wet curing
Wet curing keeps concrete moist by covering it with water-saturated materials like burlap, promoting proper hydration.
Question 2: What is the primary purpose of adding fly ash as a supplementary cementitious material in concrete?
- Increase early strength
- Reduce water demand and improve long-term durability (Correct answer)
- Increase unit weight
- Speed up setting time
Correct answer: Reduce water demand and improve long-term durability
Fly ash reduces water demand, improves workability, and enhances long-term durability and resistance to sulfate attack.
Question 3: In steel construction, what does the term 'camber' refer to?
- Horizontal bracing between beams
- Intentional upward curvature built into a beam (Correct answer)
- The slope of a roof beam
- The depth-to-span ratio
Correct answer: Intentional upward curvature built into a beam
Camber is a deliberate upward curve built into a beam so that under load it deflects back to a level position.
Question 4: Which masonry unit is classified as a hollow unit under ASTM standards?
- Solid brick with net area ≥ 80%
- Concrete masonry unit with core area > 25% of gross area (Correct answer)
- Adobe block
- Rubble stone
Correct answer: Concrete masonry unit with core area > 25% of gross area
ASTM C90 defines a hollow CMU as one whose net cross-sectional area in any plane is less than 75% of its gross cross-sectional area.
Question 5: What is the standard slump range for normal structural concrete used in columns and walls?
- 0–1 inch
- 2–4 inches (Correct answer)
- 6–8 inches
- 9–10 inches
Correct answer: 2–4 inches
Normal structural concrete for columns and walls typically requires a slump of 2–4 inches to balance workability with strength.
Question 6: Which type of pile is most suitable for soils with obstructions or boulders that prevent driven piles from reaching bearing strata?
- Timber friction pile
- Steel H-pile
- Auger-cast (ACIP) pile (Correct answer)
- Precast concrete pile
Correct answer: Auger-cast (ACIP) pile
Auger-cast in-place (ACIP) piles are drilled into place, allowing them to penetrate past obstructions and reach bearing strata.
CPC CPC Construction Methods & Materials 1
Which concrete curing method involves covering freshly placed concrete with wet burlap or curing blankets?