NETTCP Sampling Methods 4

Question 1

What is the purpose of a 'split sample' in transportation materials testing?

Accepted Answer

To create two identical samples for independent testing or referee analysis

Answer

Split samples allow independent verification by the agency and contractor, or serve as a referee sample if results are disputed.

Question 2

When sampling liquid asphalt binder from a delivery tanker, from which location should the sample be drawn?

Accepted Answer

Through the sample valve at a mid-level or from multiple points

Answer

Sampling through a dedicated sample valve or at multiple tank levels ensures a representative sample of the homogeneous binder.

Question 3

According to AASHTO practice, pavement cores taken for density determination should be extracted at what minimum distance from the edge of the pavement?

Accepted Answer

12 inches

Answer

Cores must be taken at least 12 inches from the pavement edge to avoid edge effects that could produce unrepresentative density results.

Question 4

A technician is sampling embankment fill for moisture-density control. The fill lifts are 8 inches thick. Where should in-place density tests be located vertically within the lift?

Accepted Answer

At mid-depth of the compacted lift

Answer

Density tests should be performed at mid-depth of the compacted lift to measure the representative density of that layer.

Question 5

What does the term 'lot' refer to in pavement quality acceptance sampling plans?

Accepted Answer

A defined quantity of material for which one acceptance decision is made

Answer

A lot is a defined quantity (e.g., by tonnage or area) that is evaluated together to make a single accept/reject or pay-factor decision.

(NETTCP) New England Transportation Technician Certification Program Practice Test

(NETTCP) New England Transportation Technician Certification Program Practice Test

NETTCP Sampling Methods 4