CT 201 - Sample Prep Flashcards
Sieving thoroughness for a mechanical shaker is satisfactory if less than ___________ percent of the sample passes any one sieve by hand sieving after the specimen has been agitated in the mechanical shaker.
0.5%
Circle the best description of appropriate hand sieving.
A. Use a laterial and vertical motion
B. Provide a jarring action
C. Keep the sample moving over the sieve at all times
D. All of the above
Sample splitters shall have an _________ number of chutes.
Even
The minimum width of the splitter chutes should be approximately __________ larger than the maximum particle size.
50 percent
Sample splitters for coarse aggregate should have a minimum of ________chutes.
8
Sample splitters for fine aggregate should have a minimum of ________ chutes.
12
When air drying a sample, the max temp should not exceed ___________.
140 deg. F
A sample has been sufficiently dried for splitting when _____________.
The portion passing the No.4 sieve flows freely.
Approved methods for removing coatings from coarse agg and breaking up clods include ____________.
Using a mortar and rubber covered pestle, Using a soil pulverizing apparatus, washing the sample
Which test method governs adjusting gradings?
CT 105
Sample splitters are preferred over hand quartering.
True
The rate of discharge from the chutes should provide ____________.
A continuous rate of flow
When hand-quartering samples weighing more than 100 lbs., why may it be necessary to moisten the sample?
To prevent segregation
How is a stick or pipe used when quartering samples weighing more than 100 lbs.?
It is inserted beneath the canvas to divide the sample into two equal parts.
If the sample has been separated into basic sieve sizes, it is permissible to scoop material from the basic sieve sizes without splitting.
True
Excess portions of the sample that remain after splitting should be immediately discarded.
False