Concrete -exam 2 Test Questions with
Complete Solutions.
According to ASTM C 172 the maximum allowable time after obtaining the final portion of the
composite sample and beginning the tests for slump, temperature, and air content is _________
minutes. Water-cement ratio - Answer 5
T/F According to ASTM C 172, concrete samples from a truck mixer must be obtained before any
water or admixtures are added to the mixer at the job site - Answer False
T/F According to ASTM C 172, portions of a composite sample shall be thoroughly remixed
before beginning tests on the sample - Answer True
T/F Samples smaller than 28L (1 cu.ft.) are allowed on routine air content, temperature, and
slump tests - Answer True
T/F Typically water reducers add air to the concrete along with allowing the water to be
lessened - Answer True
T/F According to ASTM C 143 when rodding the second and third layers, you should rod through
the current layer and penetrate the previous layer 1". - Answer True
T/F After the final rodding, the sides of the slump mold should be tapped lightly with the
tamping rod - Answer False
T/F When raising the slump mold, it should not be rotated or twisted - Answer True
If you have a slump of 3 3/16 inches what do you record? - Answer 3 1/4
According to ASTM C 143, how much time (sec) is allowed to raise the slump cone for the
starting position to 12" above the ground? - Answer 3-7
When determining the temperature of fresh concrete, what is the minimum amount of concrete
cover (inch) in all directions around the thermometer? - Answer 3"
What methods to test the air in concrete? - Answer Pressure meter, Gravimetric, Volume
metric
, T/F Samples should be taken before 10% or after 90% of the batch has been discharged. -
Answer False
T/F How to determine relative yield → Ry=Y/Yd - Answer True
T/F How to determine yield in cubic yards → Y(m3)=M/D - Answer False
T/F Rod each layer 25 times when 4L or smaller measures are used - Answer True
According to ASTM C138/C138M, a plastic container can be used for the measure in the test
method - Answer False
Tests for slump and air content must be started within ___________(min) after obtaining the
final portion of the composite sample - Answer 5
T/F According to ASTM C 231, you should fill one petcock with water until water without
bubbles is expelled from the other side. Then you pump up the chamber to the initial pressure
line, and lastly close the petcocks before you open the pressure release valve - Answer True
According to the lab, what percent of cement is substituted with fly ash? - Answer 20
According to ASTM C 143, 231, 138, 173, what is the shape of the tip of the tamping rod? -
Answer Hemispherically rounded
T/F According to ASTM C 231 an aggregate correction factor must be applied to the final reading
before the % air is recorded - Answer True
T/F After the final rodding, the sides of the slump mold should be tapped lightly with the
tamping rod - Answer False
According to ASTM C 231 an aggregate correction factor must be applied to the final reading
before the % air is recorded - Answer True
According to ASTM C 31, the fineness modulus of the Fine Aggregate should not be less than
____ or more than ____ - Answer 2.3, 3.1
According to ASTM C 31, the grading requirements for Coarse Aggregate size #57 rock. What is
the maximum aggregate size? - Answer 1"
Complete Solutions.
According to ASTM C 172 the maximum allowable time after obtaining the final portion of the
composite sample and beginning the tests for slump, temperature, and air content is _________
minutes. Water-cement ratio - Answer 5
T/F According to ASTM C 172, concrete samples from a truck mixer must be obtained before any
water or admixtures are added to the mixer at the job site - Answer False
T/F According to ASTM C 172, portions of a composite sample shall be thoroughly remixed
before beginning tests on the sample - Answer True
T/F Samples smaller than 28L (1 cu.ft.) are allowed on routine air content, temperature, and
slump tests - Answer True
T/F Typically water reducers add air to the concrete along with allowing the water to be
lessened - Answer True
T/F According to ASTM C 143 when rodding the second and third layers, you should rod through
the current layer and penetrate the previous layer 1". - Answer True
T/F After the final rodding, the sides of the slump mold should be tapped lightly with the
tamping rod - Answer False
T/F When raising the slump mold, it should not be rotated or twisted - Answer True
If you have a slump of 3 3/16 inches what do you record? - Answer 3 1/4
According to ASTM C 143, how much time (sec) is allowed to raise the slump cone for the
starting position to 12" above the ground? - Answer 3-7
When determining the temperature of fresh concrete, what is the minimum amount of concrete
cover (inch) in all directions around the thermometer? - Answer 3"
What methods to test the air in concrete? - Answer Pressure meter, Gravimetric, Volume
metric
, T/F Samples should be taken before 10% or after 90% of the batch has been discharged. -
Answer False
T/F How to determine relative yield → Ry=Y/Yd - Answer True
T/F How to determine yield in cubic yards → Y(m3)=M/D - Answer False
T/F Rod each layer 25 times when 4L or smaller measures are used - Answer True
According to ASTM C138/C138M, a plastic container can be used for the measure in the test
method - Answer False
Tests for slump and air content must be started within ___________(min) after obtaining the
final portion of the composite sample - Answer 5
T/F According to ASTM C 231, you should fill one petcock with water until water without
bubbles is expelled from the other side. Then you pump up the chamber to the initial pressure
line, and lastly close the petcocks before you open the pressure release valve - Answer True
According to the lab, what percent of cement is substituted with fly ash? - Answer 20
According to ASTM C 143, 231, 138, 173, what is the shape of the tip of the tamping rod? -
Answer Hemispherically rounded
T/F According to ASTM C 231 an aggregate correction factor must be applied to the final reading
before the % air is recorded - Answer True
T/F After the final rodding, the sides of the slump mold should be tapped lightly with the
tamping rod - Answer False
According to ASTM C 231 an aggregate correction factor must be applied to the final reading
before the % air is recorded - Answer True
According to ASTM C 31, the fineness modulus of the Fine Aggregate should not be less than
____ or more than ____ - Answer 2.3, 3.1
According to ASTM C 31, the grading requirements for Coarse Aggregate size #57 rock. What is
the maximum aggregate size? - Answer 1"
