GRADED A+
For concrete with aggregates less than 3 inches, the thermometer must remain in the fresh concrete
sample a minimum of 5 minutes or until the temperature reading stabilizes. (T or F) - ➡-False (2-5
minutes)
The temperature measuring device must be accurate to within 0.1 degree. (T or F) - ➡-
The temperature measuring device shall have a capacity of measuring temperature of freshly mixed
concrete throughout a range of _____ to _____ degree F ( ______ to ______ degree C) - ➡-30 to 120
degree F ( 0 to 50 degree C)
A composite sample is not needed if only the temperature test is being run. (T or F) - ➡-True
The temperature of fresh concrete in a placement must be measured by inserting a thermometer
into the top six inches of concrete. (T or F) - ➡-False (3 in.)
The temperature of the concrete is recorded to the nearest ______ degree F (______ degree C) - ➡-
1 degree F (0.5 degree C)
ASTM C1064 states the container used to measure temperature of concrete must be large enough to
provide at least 5 inches of concrete around the sensor. (T or F) - ➡-
Calibrate the temperature measuring device at least __________, or whenever there is a question of
accuracy. - ➡-Annually
After the thermometer is placed in the concrete: - ➡-Gently press concrete around the thermometer
According to ASTM C1064, what is one reason to take the temperature of concrete? - ➡-Verify
conformance
, It is allowable to remove the temperature measuring devices from the freshly mixed concrete to read
the temperature if you cannot see the reading. (T or F) - ➡-False
The maximum allowable time between obtaining the first and last portions of the composite sample
may not exceed 5 minutes. (T or F) - ➡-False
Start molding specimens for strength tests within 30 minutes after fabricating the composite sample.
(T or F) - ➡-False (15 mins)
The composite concrete sample must be protected from sun, wind, contamination and rapid
evaporation. (T or F) - ➡-False (Contamination and rapid evaporation)
If the concrete contains aggregates larger than those that are appropriate for a size of mold or
equipment used, the sample should be wet-sieved before making the test. (T or F) - ➡-False (wet
screened)
The composite sample not be remixed before beginning any tests. (T or F) - ➡-False
Sampling should normally be performed, as the concrete is discharged from the mixer. (T or F) - ➡-
True
ASTM Method C172 includes the sampling from stationary mixers, paving mixers, truck mixers,
agitators, and non-agitating equipment. (T or F) - ➡-True
After sampling is completed, start the tests for slump and air content within: - ➡-None of the above
(5 mins)
In any case, do not obtain samples until: - ➡-All the water and admixtures have been added to the
concrete
No samples shall be taken before ______ or after ______ of the batch has been discharged. - ➡-
When strength tests are to be made, the minimum size of the composite sample shall be: - ➡-1
cubic foot