ASTM C - 172 -- CONCRETE SAMPLING Flashcards
What is the “Nominal Aggregate Size”?
Smallest specified sieve in which 100 % of the material is allowed to pass.
In Minutes
How long do you have to obtain a composite sample after the pouring of concrete?
15 Minutes
In Minutes
How long do you have to start making molds of the composite sample after obtaining it?
15 Minutes
In Minutes
How long do you have to begin testing for temperature, slump, and air content after you have obtained your sample?
5 Minutes
In ft^3 OR 1/2 a what?
What is the minimum sample size when casting “strength specimens” or molds? (ft^3)(1/2 ___)
1 ft^3 OR 1/2 a Wheelbarrow
3 Different Methods
What types of concrete delivery require not sampling the first or last 10% of the load?
1) Stationary Mixers
2) Revolving Drum Trucks
3) Open Top Mixers
When do you sample from a PAVING concrete mixer?
After ALL concrete has been discharged
When do you sample from a CONTINUOUS mixer?
In the MIDDLE portion of the batch
In ft^3 OR Feet Cubed
How much material do you FIRST allow to be discharged from a Continuous Mixer BEFORE sampling?
5 ft^3
How long do you wait BEFORE BEGINNING test AFTER obtaining the sample from a Continuous Mixer? (2-_ __)
2-5 minutes
How many sample points must you obtain from when sampling Paving Mixers?
5 different points
How long do you have to sample all points max when using paving mixers?
15 minutes
When do you need to wet sieve?
When concrete contains larger aggregate than the test equipment allows.
To Slump, Air Content, and Strength
What will wet sieving do to the air content of the concrete during testing?
Air Content will increase B/C —> Large aggregate particles are removed.
What will wet sieving do to the slump of the concrete during testing?
Slump will increase –> B/C large aggregate particles are removed.
