Comprehensive Guide to ASTM C231 Air
Content Testing Procedures and
Corrections Exam Questions and
Answers with Verified Solutions | Latest
Updated 2026
What does ASTM C231 NOT Air contained within aggregate voids
measure in terms of air?
Why is an aggregate Because C231 excludes air inside
correction factor needed? aggregate particles
What happens if you don't Air content will be incorrectly high
apply the aggregate correction
factor?
Which meter type is affected Type A
by changes in barometric
pressure?
Which meter type is NOT Type B
affected by barometric
pressure?
What happens if the meter is Air loss causes inaccurate readings
not perfectly sealed?
What indicates a leak during Water level does not return to zero
calibration?
, What is the purpose of tapping To release trapped air and relieve
the bowl during testing? local restraints
What happens if you don't tap Air content may read falsely low or
enough? inconsistent
What happens if you over-tap Loss of entrained air → falsely low air
or over-vibrate? content
What slump requires rodding >75 mm (3 in.)
only?
What slump allows either 25-75 mm (1-3 in.)
rodding or vibration?
What slump requires <25 mm (1 in.)
vibration?
How deep should the rod About 25 mm (1 in.)
penetrate into the previous
layer?
What happens if you don't Poor consolidation and inaccurate
penetrate layers properly? air results
Why must the bowl be struck Ensures correct volume for accurate
off level? air calculation
What happens if the bowl is Invalid test results
overfilled or underfilled?
Why must internal surfaces be Prevents air bubbles from sticking to
wet before testing? surfaces
Content Testing Procedures and
Corrections Exam Questions and
Answers with Verified Solutions | Latest
Updated 2026
What does ASTM C231 NOT Air contained within aggregate voids
measure in terms of air?
Why is an aggregate Because C231 excludes air inside
correction factor needed? aggregate particles
What happens if you don't Air content will be incorrectly high
apply the aggregate correction
factor?
Which meter type is affected Type A
by changes in barometric
pressure?
Which meter type is NOT Type B
affected by barometric
pressure?
What happens if the meter is Air loss causes inaccurate readings
not perfectly sealed?
What indicates a leak during Water level does not return to zero
calibration?
, What is the purpose of tapping To release trapped air and relieve
the bowl during testing? local restraints
What happens if you don't tap Air content may read falsely low or
enough? inconsistent
What happens if you over-tap Loss of entrained air → falsely low air
or over-vibrate? content
What slump requires rodding >75 mm (3 in.)
only?
What slump allows either 25-75 mm (1-3 in.)
rodding or vibration?
What slump requires <25 mm (1 in.)
vibration?
How deep should the rod About 25 mm (1 in.)
penetrate into the previous
layer?
What happens if you don't Poor consolidation and inaccurate
penetrate layers properly? air results
Why must the bowl be struck Ensures correct volume for accurate
off level? air calculation
What happens if the bowl is Invalid test results
overfilled or underfilled?
Why must internal surfaces be Prevents air bubbles from sticking to
wet before testing? surfaces
