CTQP Materials Sampling and Testing 4

Question 1

When performing a field density test using the nuclear gauge method, the gauge must be kept at least how far from any wall or vertical obstruction?

Accepted Answer

12 inches

Answer

Nuclear gauges must be kept at least 12 inches from walls or vertical obstructions to prevent backscatter interference that could affect readings.

Question 2

Which AASHTO standard governs the procedure for reducing field samples of aggregate to testing size?

Accepted Answer

AASHTO T 248

Answer

AASHTO T 248 covers the standard method of test for reducing samples of aggregate to testing size using splitting or quartering techniques.

Question 3

A bituminous mixture sample collected from behind the paver should be tested for temperature within how many minutes of sampling?

Accepted Answer

10 minutes

Answer

Mix temperature must be measured within 10 minutes of sampling to ensure the reading accurately reflects the in-place material condition.

Question 4

The term 'lot' in materials acceptance testing typically refers to:

Accepted Answer

A defined quantity of material for statistical acceptance purposes

Answer

A lot is a defined quantity of material (such as a specified tonnage or lane-miles) used as the statistical unit for acceptance sampling and testing.

Question 5

When sampling hot mix asphalt from a truck, the standard practice is to discard how much material from the tailgate before collecting the sample?

Accepted Answer

The first few shovelfuls

Answer

The first few shovelfuls from the tailgate are discarded because edge material may be unrepresentative due to segregation during haul.

CTQP - Construction Training & Qualification Program Practice Test