CCIL Superpave Mix Design 2

Question 1

In Superpave mix design, what does the term 'N_design' refer to?

Accepted Answer

The number of gyrations used to compact specimens to the design air void level

Answer

The number of aggregate gradation points required

Answer

The nominal maximum aggregate size in millimeters

Answer

The number of binder performance grade tests required

Question 2

Which Superpave aggregate property measures resistance to polishing under traffic?

Accepted Answer

Flat and Elongated particle content

Answer

Coarse Aggregate Angularity (CAA)

Answer

Sand Equivalent (SE)

Answer

Los Angeles Abrasion value

Question 3

What is the primary purpose of the Superpave gyratory compactor (SGC)?

Accepted Answer

To simulate field compaction by applying a kneading action with a fixed angle and pressure

Answer

To measure the resilient modulus of asphalt mixtures

Answer

To determine the optimum binder content by measuring density at failure

Answer

To compact specimens for indirect tensile strength testing only

Question 4

In Superpave volumetric design, VMA stands for:

Accepted Answer

Voids in the Mineral Aggregate

Answer

Volume of Mineral Aggregate

Answer

Volumetric Mix Analysis

Answer

Void Maximum Allowance

Question 5

A Superpave mix design shows VFA = 58% at the design air void content. What does this indicate?

Accepted Answer

The binder fills only 58% of the VMA, which may be too low for adequate durability

Answer

The mix has too much binder and may bleed under traffic

Answer

The mix meets typical requirements for high-traffic roadways

Answer

The aggregate gradation passes through the restricted zone

Question 6

Which parameter is used to select the Superpave performance grade (PG) binder for a given project?

Accepted Answer

Design pavement temperature range at the project location and traffic level

Answer

Annual average daily traffic (AADT) and aggregate gradation

Answer

Marshall stability and flow values at the site

Answer

The sand equivalent value of the local aggregate source

Question 7

In Superpave, what is the significance of the 'restricted zone' on the 0.45-power gradation chart?

Accepted Answer

Gradations passing through this zone were found to produce tender mixes prone to rutting, though its use is now optional

Answer

Aggregates must pass through this zone to ensure adequate VMA

Answer

It defines the maximum allowable amount of natural sand in the mix

Answer

It marks the boundary between coarse-graded and fine-graded mixes