CCIL Advanced Aggregate Characterization 3

Question 1

The uncompacted void content of fine aggregate (ASTM C1252) is used primarily to evaluate which aggregate property?

Accepted Answer

Particle angularity and surface texture

Answer

Uncompacted void content measures the voids in a loosely poured sample; higher void content indicates more angular particles with rougher surface textures.

Question 2

What does a high flakiness index value in coarse aggregate indicate about its particle shape?

Accepted Answer

A high proportion of thin, plate-like particles

Answer

A high flakiness index indicates that a significant proportion of aggregate particles are flat and plate-like, which can negatively affect workability and durability.

Question 3

Per ASTM D4791, a coarse aggregate particle is classified as flat and elongated when its longest dimension to shortest dimension ratio exceeds which threshold?

Accepted Answer

5:1

Answer

ASTM D4791 defines a particle as flat and elongated when the ratio of maximum to minimum dimension exceeds 5:1 using a proportional caliper device.

Question 4

Which method is used to measure the fracture faces on coarse aggregate particles to assess angularity for use in HMA design?

Accepted Answer

ASTM D5821 Fractured Particle Count

Answer

ASTM D5821 involves manually counting the percentage of particles with one or more fractured faces, quantifying angularity for hot mix asphalt design criteria.

Question 5

In advanced aggregate characterization, what does a low bulk specific gravity value typically suggest about an aggregate's internal structure?

Accepted Answer

High internal porosity or lightweight mineralogy

Answer

A low bulk specific gravity indicates that the aggregate has significant internal porosity or consists of inherently lightweight minerals, affecting unit weight and durability.

CCIL - Canadian Council of Independent Laboratories Practice Test

CCIL - Canadian Council of Independent Laboratories Practice Test

CCIL Advanced Aggregate Characterization 3