ACI CONCRETE STRENGTH TESTING
TECHNICIAN SAMPLE WRITTEN EXAM
REVIEW SHEET WITH VERIFIED ANSWERS
GRADED A+
⩥ What is the minimum thickness for a glass or acrylic strike-off plate?
Answer: 1/2 in. [12 mm]
⩥ What is the specified weight of the mallet used on measures that are
0.5 ft^3 [14 L] or smaller?
Answer: 1.25 +- 0.50 lb. [600 +- 200 g]
⩥ Measures other than air meter bowls used for this test must conform
to ASTM _____.
Answer: C29
⩥ Air meter bowls used for this test must conform to ASTM _____ and
be calibrated for volumee according to ASTM _____.
Answer: C231, C29
⩥ The concrete sample must be obtained in accodance with what ASTM
method?
,Answer: C172
⩥ What method of consolidation must be used when the slump is greater
than 3 in. [75 mm]?
Answer: Rodding
⩥ What method of consolidation must be used when the slump is less
than 1 in. (25 mm]?
Answer: Vibration
⩥ If rodding is the method of consolidation being used, the measure
must be filled in how many layers?
Answer: 3
⩥ For a measure of 0.5 ft^3 [14 L], what is the required number of
strokes of the tamping rod for consolidation of each layer?
Answer: 25
⩥ When rodding the middle and the top layers, the tamping rod should
penetrate into the layer below approximately _____.
Answer: 1 in. [25 mm]
⩥ If vibration is the method of consolidation, the measure must be filled
in _____ approximately equal layers.
, Answer: 2
⩥ If, after consolidation of the final layer, the concrete level is 1/2 in.
(13 mm) above the top of the measure, what should be done?
Answer: Remove a representative portion of the excess concrete with a
trowel or scoop
⩥ After consolidation of the final layer, an excess of concrete ____
above the top of the measure is considered optimum.
Answer: 1/8 in. [3 mm]
⩥ After completing the strike-off procedure, what must be done before
weighing the measure and sample?
Answer: Clean off any excess concrete
⩥ The pressure method of determining air content can be used on
concrete containing _____ _____ aggregate.
Answer: Relatively Dense
⩥ The pressure method of determining air content cannot be used on
concrete containing the following types of aggregates, _____, _____,
_____.
Answer: Lightweight, air-cooled blast furnace slag, or aggregates of
high porosity
TECHNICIAN SAMPLE WRITTEN EXAM
REVIEW SHEET WITH VERIFIED ANSWERS
GRADED A+
⩥ What is the minimum thickness for a glass or acrylic strike-off plate?
Answer: 1/2 in. [12 mm]
⩥ What is the specified weight of the mallet used on measures that are
0.5 ft^3 [14 L] or smaller?
Answer: 1.25 +- 0.50 lb. [600 +- 200 g]
⩥ Measures other than air meter bowls used for this test must conform
to ASTM _____.
Answer: C29
⩥ Air meter bowls used for this test must conform to ASTM _____ and
be calibrated for volumee according to ASTM _____.
Answer: C231, C29
⩥ The concrete sample must be obtained in accodance with what ASTM
method?
,Answer: C172
⩥ What method of consolidation must be used when the slump is greater
than 3 in. [75 mm]?
Answer: Rodding
⩥ What method of consolidation must be used when the slump is less
than 1 in. (25 mm]?
Answer: Vibration
⩥ If rodding is the method of consolidation being used, the measure
must be filled in how many layers?
Answer: 3
⩥ For a measure of 0.5 ft^3 [14 L], what is the required number of
strokes of the tamping rod for consolidation of each layer?
Answer: 25
⩥ When rodding the middle and the top layers, the tamping rod should
penetrate into the layer below approximately _____.
Answer: 1 in. [25 mm]
⩥ If vibration is the method of consolidation, the measure must be filled
in _____ approximately equal layers.
, Answer: 2
⩥ If, after consolidation of the final layer, the concrete level is 1/2 in.
(13 mm) above the top of the measure, what should be done?
Answer: Remove a representative portion of the excess concrete with a
trowel or scoop
⩥ After consolidation of the final layer, an excess of concrete ____
above the top of the measure is considered optimum.
Answer: 1/8 in. [3 mm]
⩥ After completing the strike-off procedure, what must be done before
weighing the measure and sample?
Answer: Clean off any excess concrete
⩥ The pressure method of determining air content can be used on
concrete containing _____ _____ aggregate.
Answer: Relatively Dense
⩥ The pressure method of determining air content cannot be used on
concrete containing the following types of aggregates, _____, _____,
_____.
Answer: Lightweight, air-cooled blast furnace slag, or aggregates of
high porosity
