ACI Test 2023 Questions and Answers 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
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.
The container for the concrete shall be large enough to provide at least ___ inches, or _____ of coarse agg, of concrete in all directions around the TMD - Answer- 3in., 3 x NMS
The temperature measuring device shall have the capability of measuring the temperature of the freshly mixed concrete to ± ______ oF accuracy and have a
range of ______ to ______ oF. - Answer- 1,30to120 A composite sample of concrete is not required even if the only purpose for obtaining the sample is to determine temperature. T or F - Answer- T
The Temperature Measuring Device used for determining concrete temperature must be calibrated ______ or whenever there is a question of accuracy. - Answer- annually
The temperature of freshly mixed concrete can be measured in - Answer- all of the above
Submerge the sensing portion of the thermometer at least ______ inches into the concrete - Answer- 3
Gently press concrete around the thermometer such that the_______ does not
affect the reading. - Answer- ambient air temp
The thermometer must remain in the concrete during the measurement for a minimum of ______ minutes. In addition, the temperature measurement must be completed within
_______ minutes after obtaining the sample. - Answer- 2, 5
The temperature of freshly mixed concrete is measured and recorded to the nearest _____ - Answer- 1 degree
SLUMP TEST - Answer- ****The slump test does not provide an indication of the water content of a concrete mixture. - Answer- F
A slump mold can be fabricated from both plastic and metal. - Answer- T
****The length of the tamping for the slump test shall be approximately - Answer- The slump test is applicable to concrete having a coarse aggregate up to _______ inch in size. - Answer- 1.5 inches
The height of the slump cone is - Answer- 12 in
6. The exterior of the slump cone is tapped 10 to 15 times after rodding each layer. - Answer- F
The slump mold is filled with three layers of concrete - Answer- by volume
8. If the top surface of the concrete falls below the top of the slump cone while rodding the final layer of concrete, - Answer- stop, add concrete to maintain an excess, then continue the rod count from
where you left off.
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
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.
The container for the concrete shall be large enough to provide at least ___ inches, or _____ of coarse agg, of concrete in all directions around the TMD - Answer- 3in., 3 x NMS
The temperature measuring device shall have the capability of measuring the temperature of the freshly mixed concrete to ± ______ oF accuracy and have a
range of ______ to ______ oF. - Answer- 1,30to120 A composite sample of concrete is not required even if the only purpose for obtaining the sample is to determine temperature. T or F - Answer- T
The Temperature Measuring Device used for determining concrete temperature must be calibrated ______ or whenever there is a question of accuracy. - Answer- annually
The temperature of freshly mixed concrete can be measured in - Answer- all of the above
Submerge the sensing portion of the thermometer at least ______ inches into the concrete - Answer- 3
Gently press concrete around the thermometer such that the_______ does not
affect the reading. - Answer- ambient air temp
The thermometer must remain in the concrete during the measurement for a minimum of ______ minutes. In addition, the temperature measurement must be completed within
_______ minutes after obtaining the sample. - Answer- 2, 5
The temperature of freshly mixed concrete is measured and recorded to the nearest _____ - Answer- 1 degree
SLUMP TEST - Answer- ****The slump test does not provide an indication of the water content of a concrete mixture. - Answer- F
A slump mold can be fabricated from both plastic and metal. - Answer- T
****The length of the tamping for the slump test shall be approximately - Answer- The slump test is applicable to concrete having a coarse aggregate up to _______ inch in size. - Answer- 1.5 inches
The height of the slump cone is - Answer- 12 in
6. The exterior of the slump cone is tapped 10 to 15 times after rodding each layer. - Answer- F
The slump mold is filled with three layers of concrete - Answer- by volume
8. If the top surface of the concrete falls below the top of the slump cone while rodding the final layer of concrete, - Answer- stop, add concrete to maintain an excess, then continue the rod count from
where you left off.
