PIC Mix Design & Specification Compliance Flashcards

In Superpave mix design, the performance grade (PG) of an asphalt binder is primarily determined by:

Answer: The high and low pavement design temperatures at the project location

Superpave PG binder grading is based on the high and low pavement design temperatures at the project site, ensuring the binder performs adequately across the climate range.

What does VMA stand for in hot-mix asphalt mix design?

Answer: Voids in the Mineral Aggregate

VMA (Voids in the Mineral Aggregate) is the total volume of inter-granular void space in a compacted mix, including air voids and effective asphalt binder content.

A job mix formula (JMF) specifies the target gradation and binder content for an HMA mix. On a project, inspectors must verify that production mix properties are within:

Answer: The allowable tolerances established in the project specifications

Production mix properties must fall within the specification tolerances established around the JMF targets; deviations outside these limits require corrective action.

The Nominal Maximum Aggregate Size (NMAS) of a Superpave mix is defined as:

Answer: One sieve size larger than the first sieve to retain more than 10% of the aggregate

NMAS in Superpave is one standard sieve size larger than the first sieve that retains more than 10% of the combined aggregate blend.

Which mix design method was widely used before Superpave became the FHWA standard and relies on stability and flow measurements from a standardized hammer-compacted specimen?

Answer: Marshall Mix Design

The Marshall Mix Design method, which measures stability and flow of hammer-compacted specimens, was the dominant HMA design procedure before Superpave.

Target air void content for a Superpave design mix at Ndesign gyrations is:

Answer: 4%

Superpave mix design targets 4% air voids at the design number of gyrations (Ndesign), balancing durability and resistance to rutting.