ACI CERTIFICATION: PERFORMANCE CHECKLIST QUESTIONS
WITH CORRECT ANSWERS 2025/2026
What must occur before a sample of concrete can be taken from a revolving drum mixer? -
CORRECT ANSWER -All water and admixtures must be added to the mixer.
When sampling from a stationary or revolving drum mixer, what is collected and when is it taken
during discharge? - CORRECT ANSWER -In two or more portions of concrete, at regularly spaced
intervals, and from the middle of the batch.
How are the sample portions obtained from the discharge stream of a stationary or revolving
drum mixer? - CORRECT ANSWER -Repeatedly pass a receptacle through the entire discharge
stream. Completely divert the discharge stream into a sample container.
Describe the procedure for collecting a sample from a paving mixer. - CORRECT ANSWER -
Discharge the contents of the paving mixer. Obtain samples from at least five different portions
of the pile.
What is the minimum size for a sample when strength test specimens are to be molded? -
CORRECT ANSWER -28 L (1 cubic foot)
What is the maximum allowable time between obtaining the first and final portions of the
composite sample? - CORRECT ANSWER -15 minutes
What action is required after the individual concrete samples have been transported to the
place where tests are to be performed? - CORRECT ANSWER -Combine and remix the samples
with a shovel.
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WITH CORRECT ANSWERS 2025/2026
What must occur before a sample of concrete can be taken from a revolving drum mixer? -
CORRECT ANSWER -All water and admixtures must be added to the mixer.
When sampling from a stationary or revolving drum mixer, what is collected and when is it taken
during discharge? - CORRECT ANSWER -In two or more portions of concrete, at regularly spaced
intervals, and from the middle of the batch.
How are the sample portions obtained from the discharge stream of a stationary or revolving
drum mixer? - CORRECT ANSWER -Repeatedly pass a receptacle through the entire discharge
stream. Completely divert the discharge stream into a sample container.
Describe the procedure for collecting a sample from a paving mixer. - CORRECT ANSWER -
Discharge the contents of the paving mixer. Obtain samples from at least five different portions
of the pile.
What is the minimum size for a sample when strength test specimens are to be molded? -
CORRECT ANSWER -28 L (1 cubic foot)
What is the maximum allowable time between obtaining the first and final portions of the
composite sample? - CORRECT ANSWER -15 minutes
What action is required after the individual concrete samples have been transported to the
place where tests are to be performed? - CORRECT ANSWER -Combine and remix the samples
with a shovel.
Whatwshouldwbewdonewifwthewconcretewcontainswaggregatewlargerwthanwiswappropriatewforwthewsize
wofwthewmoldsworwthewequipmentwbeingwused?w-wCORRECTwANSWERw-Wetwsieving
