Sampling Freshly Mixed Concrete Flashcards
Sampling by this method is required when tests are to be made to determine _____ with specification requirements.
Compliance
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
Portions of a composite sample shall be thoroughly remixed before beginning tests on the sample. T/F
True
The max elapsed time allowed between obtaining the final portion of the composite sample and beginning the tests for slump, temp, 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 evaportion
The minimum size sample for making strength test specimens is ____.
28 L (1 cubic foot)
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 portion of the batch of concrete taken from the pile after discharge.
5
When sampling from a revolving drum truck mixer, concrete must be sampled at a min of ___ regularly spaced intervals during discharge of the middle portion of this batch.
2
Concrete samples from a truck mixer must be obtained before any water or admixtures are added to the mixer at the job site. T/F
False
The composite samples from a truck mixer must be obtained from the ___ portion of the batch.
Middle
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 sieved
