ACI Test Questions with Verified
Solutions
The total time allowed between obtaining the first and final portions of a composite
sample is - ANSWER-15 minutes
When it is necessary to wet sieve the concrete sample, wet sieving should be
performed after the individual samples are remixed into a composite sample (T or F) -
ANSWER-F
Tests for slump, temperature, and air content must begin within ______ minutes after
obtaining the composite sample - ANSWER-5 minutes
Begin molding test specimens within ______ minutes after obtaining the composite
sample - ANSWER-15 minutes
The concrete samples should be protected from - ANSWER-the sun, wind, and other
sources of rapid evaporation, from contamination
When test specimens are to be molded, the minimum size of sample obtained is -
ANSWER-28 L (1 ft^3)
The primary objective of the sampling process is to obtain a representative sample (T or
F) - ANSWER-T
When sampling from a revolving drum truck mixer collect concrete from ______ portions
of the batch - ANSWER-2 or more
When the coarse aggregate of a concrete mixture can be retained on a 2in. sieve, wet
sieve a sufficient amount of material for the air content test (ASTM C 231) over a
______ sieve - ANSWER-1.5 in
Proper consolidation of concrete in the bowl of the pressure meter is accomplished by -
ANSWER-either rodding or vibration depending on the slump of the concrete
Strike off the top surface of the concrete by using - ANSWER-either strike off bar or
plate
The length of the tamping rod for the air pressure test shall not be less than - ANSWER-
16 in
, 7. Assume that the reading from the dial gage is 5.5% and the aggregate correction
factor for the concrete mixture is 0.5%. The final air content for this mixture is -
ANSWER-5.5 - 0.5% = 5.0%
After completion of the air test - ANSWER-a. release the pressure in the bowl by
opening the petcocks.
AIR CONTENT BY ROLL A METER - ANSWER-
It is permissible to use the Volumetric Method to determine the air content of fresh
concrete made with - ANSWER-lightweight aggregates only
2. The volumetric method measures the volume of air present within - ANSWER-the
paste fraction only
3. The purpose for adding isopropyl alcohol to the volumetric meter is to - ANSWER-
help dissolve the foam that can be created during the test
4. Wet sieve a sufficient amount of material for the volumetric air content test over a
______ in. sieve when the coarse aggregate for the mixture can be retained on a 1.5in.
sieve. - ANSWER-1
5. The bowl of the volumetric meter is filled in ______ layers of equal depth. -
ANSWER-2
6. The excess concrete above the rim of the bowl is struck off using - ANSWER-strike
off bar
7. Prior to adding any isopropyl alcohol to the meter, it is necessary to add at least ____
of water. - ANSWER-1 pint
8. The meter should be inverted and agitated for at least - ANSWER-45 sec
. The rolling process should be continued for a minimum of - ANSWER-1min
Wet sieving is performed - ANSWER-when the concrete contains aggregates larger
than appropriate for a test
When sampling from a paving mixer it is not acceptable to place 3 small containers on
the sub grade in order to obtain the required samples of concrete (T or F) - ANSWER-F
TEMPERATURE - ANSWER-
it may require up to ___ min before the temp stabilizes when the NMS of the coarse agg
is greater than ___ - ANSWER-20min., 3in.
Solutions
The total time allowed between obtaining the first and final portions of a composite
sample is - ANSWER-15 minutes
When it is necessary to wet sieve the concrete sample, wet sieving should be
performed after the individual samples are remixed into a composite sample (T or F) -
ANSWER-F
Tests for slump, temperature, and air content must begin within ______ minutes after
obtaining the composite sample - ANSWER-5 minutes
Begin molding test specimens within ______ minutes after obtaining the composite
sample - ANSWER-15 minutes
The concrete samples should be protected from - ANSWER-the sun, wind, and other
sources of rapid evaporation, from contamination
When test specimens are to be molded, the minimum size of sample obtained is -
ANSWER-28 L (1 ft^3)
The primary objective of the sampling process is to obtain a representative sample (T or
F) - ANSWER-T
When sampling from a revolving drum truck mixer collect concrete from ______ portions
of the batch - ANSWER-2 or more
When the coarse aggregate of a concrete mixture can be retained on a 2in. sieve, wet
sieve a sufficient amount of material for the air content test (ASTM C 231) over a
______ sieve - ANSWER-1.5 in
Proper consolidation of concrete in the bowl of the pressure meter is accomplished by -
ANSWER-either rodding or vibration depending on the slump of the concrete
Strike off the top surface of the concrete by using - ANSWER-either strike off bar or
plate
The length of the tamping rod for the air pressure test shall not be less than - ANSWER-
16 in
, 7. Assume that the reading from the dial gage is 5.5% and the aggregate correction
factor for the concrete mixture is 0.5%. The final air content for this mixture is -
ANSWER-5.5 - 0.5% = 5.0%
After completion of the air test - ANSWER-a. release the pressure in the bowl by
opening the petcocks.
AIR CONTENT BY ROLL A METER - ANSWER-
It is permissible to use the Volumetric Method to determine the air content of fresh
concrete made with - ANSWER-lightweight aggregates only
2. The volumetric method measures the volume of air present within - ANSWER-the
paste fraction only
3. The purpose for adding isopropyl alcohol to the volumetric meter is to - ANSWER-
help dissolve the foam that can be created during the test
4. Wet sieve a sufficient amount of material for the volumetric air content test over a
______ in. sieve when the coarse aggregate for the mixture can be retained on a 1.5in.
sieve. - ANSWER-1
5. The bowl of the volumetric meter is filled in ______ layers of equal depth. -
ANSWER-2
6. The excess concrete above the rim of the bowl is struck off using - ANSWER-strike
off bar
7. Prior to adding any isopropyl alcohol to the meter, it is necessary to add at least ____
of water. - ANSWER-1 pint
8. The meter should be inverted and agitated for at least - ANSWER-45 sec
. The rolling process should be continued for a minimum of - ANSWER-1min
Wet sieving is performed - ANSWER-when the concrete contains aggregates larger
than appropriate for a test
When sampling from a paving mixer it is not acceptable to place 3 small containers on
the sub grade in order to obtain the required samples of concrete (T or F) - ANSWER-F
TEMPERATURE - ANSWER-
it may require up to ___ min before the temp stabilizes when the NMS of the coarse agg
is greater than ___ - ANSWER-20min., 3in.
