Quizlet Cards Flashcards
The temperature measuring device shall have a capacity of measuring temperature of freshly mixed concrete to +- _____ degrees F [+- _____ C] throughout a range of _____.
1 degree F [0.5 C], 30 degrees F to 120 F [0 C to 50 C]
The temperature measuring device shall be calibrated _____, or whenever there is a question of _____.
Annually, accuracy
The temperature of concrete may be measured in a wheelbarrow. True or False?
True
The temperature of concrete may be measured in a wall form. True of False
True
A composite sample of concrete is required even if the only purpose for obtaining the sample is to determine temperature. True of False?
False
What must be done to the sample container prior to sampling the concrete?
Dampen (with water)
How long must the temperature measuring device remain in the freshly mixed concrete?
At least 2 minutes but not more than 5 minutes
According to ASTM C1064, what is one reason to take the temperature of concrete?
Verify conformance to a specified requirement for temperature of concrete
This method covers sampling from four types of mixtures which are _____, _____, _____, and _____.
Stationary mixers, paving mixers, revolving drum mixers, and open top mixers
The maximum allowable time between obtaining the first and final portions of a composite sample is _____ minutes.
15
The maximum elapsed time allowed between obtaining the final portion of the composite sample and beginning the tests for slump, temperature, and air content is _____ minutes.
5
The molding of strength test specimens shall begin within _____ minutes after fabricating the composite sample.
15
The concrete sample must be protected from contamination and _____.
Rapid Evaporation
When sampling from a stationary mixer, the batch must be sampled at _____ or more regularly spaced intervals during discharge of the middle portion of the batch
2
The composite sample for a paving mixer must represent a minimum of _____ different portions of the batch of concrete taken from the pile after discharge.
5
When the concrete contains aggregate larger than that permitted for a particular test method, the sample of concrete must be _____ _____ before making the test.
Wet Seived
The slump test is applicable to plastic concrete with a maximum size aggregate of _____.
1.5 in. [37.5 mm]
When the concrete contains aggregate larger than allowed for the slump test, the large aggregate must be _____.
Removed by wet sieving the sample over 1.5 in. [37.5 mm] sieve
The interior surface of the slump mold is allowed to have minor irregularities. True or False?
False
For use in the slump test, the end or both ends of the tamping rod must be _____.
Rounded to a hemispherical tip
The sample of concrete for use in making the slump test must be obained in accordance with ASTM Standard _____.
C172, Standard Practice for Sampling Freshly Mixed Concrete
The surface on which the slump mold will be placed must be _____.
Flat, level, moist, nonabsorbent, and free of vibration
The slump mold is filled in _____ layers.
3
How deep should the tamping rod penetrate into each layer?
Rod each layer throughout its depth; on the second and final layers, the rod should penetrate into the previous layer approximately 1 in. [25 mm]
What must be done if the concrete drops below the top of the slump mold while the top layer is being rodded?
Add additional concrete to keep an excess of concrete above the top of the mold at all times
How much time is allowed for lifting the slump mold?
5 +- 2 seconds
