NETTCP Quality Control 2

Question 1

When performing a sieve analysis on aggregate, which sieve size is used to define the boundary between coarse and fine aggregate?

Accepted Answer

No. 4 (4.75 mm)

Answer

The No. 4 sieve (4.75 mm) is the standard boundary between coarse and fine aggregate in ASTM and AASHTO specifications.

Question 2

What does the term 'plasticity index' (PI) represent in soil classification?

Accepted Answer

The difference between liquid limit and plastic limit

Answer

Plasticity index is calculated as PI = LL − PL, indicating the range of moisture content over which soil behaves plastically.

Question 3

Which QC test is used to determine the in-place density of compacted asphalt pavement using a nuclear gauge?

Accepted Answer

AASHTO T 355

Answer

AASHTO T 355 covers the use of nuclear surface moisture-density gauges for testing asphalt mixtures in place.

Question 4

During concrete production, what is the primary purpose of performing a slump test?

Accepted Answer

To measure workability of fresh concrete

Answer

The slump test (ASTM C 143) measures the consistency and workability of fresh concrete before placement.

Question 5

A QC technician finds that a batch of HMA has a voids in the mineral aggregate (VMA) value below the minimum specified. What is the most likely corrective action?

Accepted Answer

Increase the percentage of coarse aggregate or adjust gradation

Answer

Low VMA is typically corrected by adjusting the aggregate gradation, often by increasing the coarse fraction to create more void space.

(NETTCP) New England Transportation Technician Certification Program Practice Test

(NETTCP) New England Transportation Technician Certification Program Practice Test

NETTCP Quality Control 2