NETTCP Asphalt Technology 5

Question 1

Which type of asphalt mix is typically used for open-graded friction course (OGFC) applications?

Accepted Answer

Gap-graded or open-graded mix with 15–20% air voids

Answer

OGFC mixes are intentionally open-graded with high air void content (15–20%) to allow water to drain through the surface, reducing hydroplaning.

Question 2

In reclaimed asphalt pavement (RAP) usage, what must be done to account for the aged binder already in RAP material?

Accepted Answer

Increase the virgin binder grade to compensate for stiffened RAP binder

Answer

Because RAP contains stiff, aged binder, the virgin binder grade is often softened (lower high-temp grade) to blend with RAP binder and achieve the target PG grade.

Question 3

What is 'shoving' in asphalt pavement, and what commonly causes it?

Accepted Answer

Transverse displacement of the pavement surface caused by braking or turning forces on unstable mix

Answer

Shoving is a form of plastic deformation where traffic braking or turning forces push asphalt laterally, creating humps or waves, often from mix instability.

Question 4

What is the function of mineral filler (material passing the No. 200 sieve) in an asphalt mix?

Accepted Answer

To fill the void space between larger aggregates and stiffen the asphalt mortar

Answer

Mineral filler fills microscopic voids between aggregate particles and stiffens the asphalt mastic, improving mix stability and durability.

Question 5

Which test is used to evaluate moisture sensitivity (stripping susceptibility) of a compacted asphalt mix?

Accepted Answer

Tensile strength ratio (TSR) test per AASHTO T 283

Answer

The TSR test compares the tensile strength of conditioned (water-soaked) specimens to unconditioned specimens; a ratio below 0.80 indicates moisture susceptibility.

(NETTCP) New England Transportation Technician Certification Program Practice Test

(NETTCP) New England Transportation Technician Certification Program Practice Test

NETTCP Asphalt Technology 5