CT 125 Agg - Sampling Flashcards
When sampling individual aggregate hot bins, what type of device is used?
Pan of sufficient size to intercept the entire cross section of the discharge stream and hold the required quantity of material without overflow.
Where is one location that baghouse dust can be sampled?
From the bottom of the baghouse, from the feed line, or from the surge tank preceding the proportioning device.
Where is the aggregate normally sampled at an HMA continuous mixing plant?
From a sampling device located in advance of the point where the aggregate enters the drier-drum mixer.
What are the functional requirements of the sampling device?
The sampling device must intercept the entire cross-section of the discharge stream and hold the required quantity of material without overflowing.
Where should aggregates be sampled at a concrete batch plant?
From the belt feeding the batch plant bins immediately preceding the weigh hopper.
When taking a belt cut from a feed belt, how many templates should be used?
Two
What shape should the templates be?
The templates should conform to the shape of the belt.
Once the belt is stopped and the templates are in place, how should the sample be taken?
Completely remove the material between the templates, including all fines.
Where in a windrow should samples be taken?
From the middle half
How should windrow samples be taken?
Isolate the sample area using steel or plywood templates and remove the entire cross section of the windrow before water is added.
When aggregate has been spread but not yet compacted, how many locations transversely across the roadway section should be sampled?
3 minimum
How deep into the roadway should aggregate be taken?
Full depth, being careful to exclude underlying material.
For any given aggr. type, what amount of material should be sampled?
An amount that meets or exceeds the quantity needed for subsequent testing
When sampling agg. from HMA batch plants, who is responsible for providing the sampling device?
Contractor
Where can supplemental fine aggregate be sampled from at an HMA batch plant?
Feed line and Surge tank
When sampling agg. from HMA continuous plants, where must the sampling device be located?
Before the dryer-drum mixer
When sampling agg, intercept the entire cross section of the discharge stream.
True
When diverting the whole stream of aggregate for sampling, the first _____and last ______ should be wasted.
1/4, 1/4
When using the sampler at the bottom of the baghouse, it is not necessary to clean the pipe prior to sampling the baghouse dust.
False
When sampling agg. from Portland cement concrete batch plants, templates are not required to obtain belt cut.
False
The following statements apply when sampling agg from windrows.
Use steel plates to isolate a sample in the middle half of the windrow. Remove a cross section equal to the width of a shovel or wider and obtain a sample from a vertical cut on either of the exposed faces.
When sampling aggregate from roadways, wait until the material has been compacted to model actual conditions.
False
When sampling agg. from transporation units, the sample should be obtained a distance from the edge that is about one -quarter of the bed width.
False. 1/3
Which statement apply when sampling agg from a stockpile and power equip is not available?
The sample should consist of at least three portions, material should be obtained from the top third, and bottom third. A board placed in the stockpile just above the sampling location can reduce segregation.
When sampling soil from the source, it is permissible to create a composite sample of different material types.
False
When sampling lime slurry, obtain at least _______ of material.
Two 1 quart cans.
