ACI Concrete Field Testing Technician-
Grade I 2025
What method of consolidation must be used when the slump is greater than
3 in. [75 mm]? - >>Rodding
ANSWER
What method of consolidation must be used when the slump is less than 1
in. (25 mm]? - >>Vibration
ANSWER
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. - >>1/8 in. [3
ANSWERmm]
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
What is the minimum allowable capacity of the measuring bowl used in this
test method? - >>6 L (0.20 ft^3)
ANSWER
What are the required characteristics of the tamping rod used in this test
method? - ANSWER>>Round, straight steel rod, with a 16 mm [5/8 in.] +- 2
mm [1/16 in.] diameter, length at least 100 mm [4 in.] greater than the depth
of the measuring bowl, but not greater than 600 mm [24 in.] in overall
length, with the tamping end rounded to a hemispherical tip of the same
diameter as the rod.
What is the specified size of the mallet required for this test method when
the measuring bowl has the capacity of 14 L [0.5 ft^3] or less? -
ANSWER >>0.60 +- 0.25 kg [1.25 +- 0.50 lb.]
The sample of concrete used for this test is to be obtained in accordance
with what ASTM Standard? - ANSWER
>>C172
The maximum size aggregate allowed for this test method is _____. -
, ANSWER >>50 mm (2
in.)
If the concrete contains aggregate larger than the maximum allowed for this
test, the sample must be _____. - ANSWER>>Wet sieved over a 1 1/2 in.
(37.5 mm) sieve
If the concrete sample is to be consolidated by rodding, the measure is
filled in _____ layers. - >>3
ANSWERequal
If the concrete sample is to be consolidated by vibration, the measure is
filled in _____ layers. - >>2
ANSWERequal
When rodding the concrete sample, what is the specified number of strokes
required for each layer? - ANSWER
>>25
Vibration of the concrete sample is not allowed when the slump of concrete
exceeds _____. - >>75 mm (3 in.)
ANSWER
In rodding the sample, how deep should the rod penetrate each layer? -
ANSWER >>Rod bottom layer to full depth; rod second and final layer
penetrating the previous layer about 25 mm (1 in.)
After rodding each layer, what should be done to the measure before
adding another layer of concrete? - ANSWER>>Tap the sides of the
measure smartly 10 to 15 times with the mallet
When consolidating the concrete by vibration, how many times should the
vibrator be inserted into each layer? - ANSWER >>Three
(3)
Grade I 2025
What method of consolidation must be used when the slump is greater than
3 in. [75 mm]? - >>Rodding
ANSWER
What method of consolidation must be used when the slump is less than 1
in. (25 mm]? - >>Vibration
ANSWER
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. - >>1/8 in. [3
ANSWERmm]
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
What is the minimum allowable capacity of the measuring bowl used in this
test method? - >>6 L (0.20 ft^3)
ANSWER
What are the required characteristics of the tamping rod used in this test
method? - ANSWER>>Round, straight steel rod, with a 16 mm [5/8 in.] +- 2
mm [1/16 in.] diameter, length at least 100 mm [4 in.] greater than the depth
of the measuring bowl, but not greater than 600 mm [24 in.] in overall
length, with the tamping end rounded to a hemispherical tip of the same
diameter as the rod.
What is the specified size of the mallet required for this test method when
the measuring bowl has the capacity of 14 L [0.5 ft^3] or less? -
ANSWER >>0.60 +- 0.25 kg [1.25 +- 0.50 lb.]
The sample of concrete used for this test is to be obtained in accordance
with what ASTM Standard? - ANSWER
>>C172
The maximum size aggregate allowed for this test method is _____. -
, ANSWER >>50 mm (2
in.)
If the concrete contains aggregate larger than the maximum allowed for this
test, the sample must be _____. - ANSWER>>Wet sieved over a 1 1/2 in.
(37.5 mm) sieve
If the concrete sample is to be consolidated by rodding, the measure is
filled in _____ layers. - >>3
ANSWERequal
If the concrete sample is to be consolidated by vibration, the measure is
filled in _____ layers. - >>2
ANSWERequal
When rodding the concrete sample, what is the specified number of strokes
required for each layer? - ANSWER
>>25
Vibration of the concrete sample is not allowed when the slump of concrete
exceeds _____. - >>75 mm (3 in.)
ANSWER
In rodding the sample, how deep should the rod penetrate each layer? -
ANSWER >>Rod bottom layer to full depth; rod second and final layer
penetrating the previous layer about 25 mm (1 in.)
After rodding each layer, what should be done to the measure before
adding another layer of concrete? - ANSWER>>Tap the sides of the
measure smartly 10 to 15 times with the mallet
When consolidating the concrete by vibration, how many times should the
vibrator be inserted into each layer? - ANSWER >>Three
(3)
