CTQP Concrete Field Inspector 2

Question 1

According to ASTM C31, what is the required curing temperature range for standard-cured concrete cylinders?

Accepted Answer

60°F to 80°F (16°C to 27°C)

Answer

ASTM C31 requires standard-cured cylinders to be maintained at 60°F to 80°F (16°C to 27°C) during initial curing.

Question 2

What does the term 'bleed water' refer to in concrete?

Accepted Answer

Water that rises to the surface due to settlement of solids

Answer

Bleed water is the water that migrates to the top surface of freshly placed concrete as the heavier solid particles settle.

Question 3

Which ASTM standard governs the sampling of fresh concrete?

Accepted Answer

ASTM C172

Answer

ASTM C172 is the standard practice for sampling freshly mixed concrete from the point of delivery.

Question 4

When testing air content by the pressure method (ASTM C231), which aggregate type makes this method NOT applicable?

Accepted Answer

Lightweight aggregate

Answer

The pressure method cannot be used with lightweight or porous aggregates because they absorb air pressure, giving inaccurate readings.

Question 5

A concrete load arrives at 8:00 AM and mixing began at 7:00 AM. Under ASTM C94, what is the latest this concrete can be discharged?

Accepted Answer

9:00 AM

Answer

ASTM C94 requires concrete to be discharged within 90 minutes of mixing or before the drum has revolved 300 times, whichever comes first.

CTQP - Construction Training & Qualification Program Practice Test