ACI Test All Answers Correct
- What is the maximum duration allowed between the first and final portions of a composite sample
collection?
The maximum allowable time between obtaining the first and last portions of a composite sample is 15
minutes.
- Should wet sieving of a concrete sample occur after the individual samples are mixed into a
composite?
False. Wet sieving should not be conducted after the samples are combined; it has distinct timing
requirements.
- After obtaining a composite sample, within how many minutes must tests for slump, temperature, and
air content commence?
These tests are required to start within 5 minutes of acquiring the composite sample.
- When must test specimens be molded after the composite sample collection?
The molding of test specimens should occur within 15 minutes after the collection of the composite
sample.
- What precautions should be taken with concrete samples to prevent negative effects?
Concrete samples should be safeguarded from sunlight, wind, rapid evaporation, and contamination.
- What is the minimum volume of concrete sample needed for molding strength test specimens?
A minimum concrete sample size of 28 liters (1 cubic foot) is required for this purpose.
- Is obtaining a representative sample the main goal of the sampling process?
True. Ensuring that the sample is representative is the key objective of the sampling procedure.
- How many portions should be collected from a revolving drum truck mixer during sampling?
Concrete should be taken from 2 or more sections of the batch when sampling from a revolving drum
truck mixer.
, - What circumstances call for wet sieving of concrete?
Wet sieving is necessary if the concrete includes aggregates larger than what is acceptable for testing.
- Is it permissible to use three small containers on the subgrade when sampling from a paving mixer?
False. This method is not acceptable for obtaining the required concrete samples.
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TEMPERATURE MEASUREMENTS
- How long may it take for temperature stabilization when the nominal maximum size (NMS) of coarse
aggregate exceeds a certain dimension?
It may take up to 20 minutes for the temperature to stabilize when the NMS of coarse aggregate is
greater than 3 inches.
- What size container is necessary to ensure proper temperature measurement in concrete?
The container must be large enough to allow for at least 3 inches (or 3 times the NMS) of concrete to
surround the temperature measuring device on all sides.
- What accuracy should the temperature measuring device have, and what range must it encompass?
The device should accurately measure temperature within ±1°F and cover a temperature range from
30°F to 120°F.
- Is a composite sample required if the only intention is to measure temperature?
True. A composite sample is not necessary for determining temperature alone.
- How frequently should the temperature measuring device be calibrated?
The calibration must be performed annually or whenever there is doubt regarding its accuracy.
- What is the maximum duration allowed between the first and final portions of a composite sample
collection?
The maximum allowable time between obtaining the first and last portions of a composite sample is 15
minutes.
- Should wet sieving of a concrete sample occur after the individual samples are mixed into a
composite?
False. Wet sieving should not be conducted after the samples are combined; it has distinct timing
requirements.
- After obtaining a composite sample, within how many minutes must tests for slump, temperature, and
air content commence?
These tests are required to start within 5 minutes of acquiring the composite sample.
- When must test specimens be molded after the composite sample collection?
The molding of test specimens should occur within 15 minutes after the collection of the composite
sample.
- What precautions should be taken with concrete samples to prevent negative effects?
Concrete samples should be safeguarded from sunlight, wind, rapid evaporation, and contamination.
- What is the minimum volume of concrete sample needed for molding strength test specimens?
A minimum concrete sample size of 28 liters (1 cubic foot) is required for this purpose.
- Is obtaining a representative sample the main goal of the sampling process?
True. Ensuring that the sample is representative is the key objective of the sampling procedure.
- How many portions should be collected from a revolving drum truck mixer during sampling?
Concrete should be taken from 2 or more sections of the batch when sampling from a revolving drum
truck mixer.
, - What circumstances call for wet sieving of concrete?
Wet sieving is necessary if the concrete includes aggregates larger than what is acceptable for testing.
- Is it permissible to use three small containers on the subgrade when sampling from a paving mixer?
False. This method is not acceptable for obtaining the required concrete samples.
---
TEMPERATURE MEASUREMENTS
- How long may it take for temperature stabilization when the nominal maximum size (NMS) of coarse
aggregate exceeds a certain dimension?
It may take up to 20 minutes for the temperature to stabilize when the NMS of coarse aggregate is
greater than 3 inches.
- What size container is necessary to ensure proper temperature measurement in concrete?
The container must be large enough to allow for at least 3 inches (or 3 times the NMS) of concrete to
surround the temperature measuring device on all sides.
- What accuracy should the temperature measuring device have, and what range must it encompass?
The device should accurately measure temperature within ±1°F and cover a temperature range from
30°F to 120°F.
- Is a composite sample required if the only intention is to measure temperature?
True. A composite sample is not necessary for determining temperature alone.
- How frequently should the temperature measuring device be calibrated?
The calibration must be performed annually or whenever there is doubt regarding its accuracy.
