ATT Aggregate Sampling & Reduction 2

Question 1

According to ASTM D75, what is the minimum number of increments required to constitute a field sample of aggregate from a conveyor belt?

Accepted Answer

3 increments taken at random intervals

Answer

ASTM D75 requires a minimum of 3 increments taken at random intervals to form a representative field sample from a conveyor belt.

Question 2

When sampling aggregates from a stockpile, where should samples generally NOT be taken from?

Accepted Answer

The outer surface or slope of the stockpile

Answer

Segregation occurs along the outer slopes of stockpiles, making surface samples unrepresentative of the bulk material.

Question 3

The purpose of a sample splitter (riffle splitter) is to:

Accepted Answer

Reduce a large sample to a smaller representative portion

Answer

A riffle splitter divides a sample into two equal halves, allowing repeated halving to reach a target sample mass while maintaining representativeness.

Question 4

Under ASTM C702, which method of sample reduction is acceptable for both fine and coarse aggregate?

Accepted Answer

Both the mechanical splitter and quartering method

Answer

ASTM C702 permits both mechanical splitting and the quartering method for reducing aggregate samples of fine or coarse aggregate.

Question 5

When using the quartering method per ASTM C702, after forming the flat circular pile and dividing into four quarters, which portions are kept?

Accepted Answer

Two diagonally opposite quarters are discarded and the other two are combined

Answer

In quartering, two diagonally opposite quarters are kept and recombined; the other two opposite quarters are discarded, ensuring a representative half-sample.

(ATT) ACI Aggregate Testing Technician Practice Test

(ATT) ACI Aggregate Testing Technician Practice Test

ATT Aggregate Sampling & Reduction 2