C172 ASTM Questions with 100% Verified
Correct Answers
What is ASTM C 172
Is the standard of obtaining & preparing concrete samples to be tested.
What is a composite sample?
Two or one portions combined in one sample & represents the entire batch
Where should concrete be sample?
From middle portion of the batch
When should testing begin?
Within Required ASTM time limit
What is the order procedure of ASTM C172?
Wait → Middle → Two → Collect → Composite → 15 → 1 → 5 → 15 → Protect."
Name the five equipment sources from which concrete samples may be obtained.
* Stationary mixers
* Paving mixers
* Revolving drum mixers
* Continuous mixers
* Open-top containers
What is the purpose of proper sampling?
To obtain a representative sample of the concrete for testing.
What if additional water or admixtures are added after the sample is taken?
, Discard the sample and obtain a new sample after the additions have been mixed into the
concrete.
Why must a sample be discarded if water or admixtures are added afterward?
The sample no longer represents the actual concrete being delivered.
What must occur before concrete can be sampled?
Ensure all water and admixtures have been added and mixed into the concrete.
What type of container is preferred for collecting and combining concrete samples
A wheelbarrow is the preferred container for sampling and mixing concrete samples.
What can be used if a wheelbarrow is not available?
Multiple 5-gallon buckets or feed buckets may be used.
Why is a concrete tub useful at the testing location?
It provides a place to combine and remix the sample before testing.
Where in the discharge should a concrete sample be taken from a truck mixer?
From the middle portion of the load, after the first 10% and before the last 10% of discharge.
How is concrete sampled behind a paver or paving mixer?
Allow concrete to discharge onto the ground and obtain portions from at least 5 different
locations representing the entire batch.
What is the minimum sample size when strength specimens are required?
At least 1 cubic foot (1 ft³) of concrete.
When determining sample size, what should be considered?
Correct Answers
What is ASTM C 172
Is the standard of obtaining & preparing concrete samples to be tested.
What is a composite sample?
Two or one portions combined in one sample & represents the entire batch
Where should concrete be sample?
From middle portion of the batch
When should testing begin?
Within Required ASTM time limit
What is the order procedure of ASTM C172?
Wait → Middle → Two → Collect → Composite → 15 → 1 → 5 → 15 → Protect."
Name the five equipment sources from which concrete samples may be obtained.
* Stationary mixers
* Paving mixers
* Revolving drum mixers
* Continuous mixers
* Open-top containers
What is the purpose of proper sampling?
To obtain a representative sample of the concrete for testing.
What if additional water or admixtures are added after the sample is taken?
, Discard the sample and obtain a new sample after the additions have been mixed into the
concrete.
Why must a sample be discarded if water or admixtures are added afterward?
The sample no longer represents the actual concrete being delivered.
What must occur before concrete can be sampled?
Ensure all water and admixtures have been added and mixed into the concrete.
What type of container is preferred for collecting and combining concrete samples
A wheelbarrow is the preferred container for sampling and mixing concrete samples.
What can be used if a wheelbarrow is not available?
Multiple 5-gallon buckets or feed buckets may be used.
Why is a concrete tub useful at the testing location?
It provides a place to combine and remix the sample before testing.
Where in the discharge should a concrete sample be taken from a truck mixer?
From the middle portion of the load, after the first 10% and before the last 10% of discharge.
How is concrete sampled behind a paver or paving mixer?
Allow concrete to discharge onto the ground and obtain portions from at least 5 different
locations representing the entire batch.
What is the minimum sample size when strength specimens are required?
At least 1 cubic foot (1 ft³) of concrete.
When determining sample size, what should be considered?
