CCIL Advanced Aggregate Characterization 5

Question 1

What is the significance of determining the clay content of aggregate using the methylene blue value (MBV) test?

Accepted Answer

It quantifies swelling clay minerals that can harm concrete durability and workability

Answer

It measures aggregate abrasion resistance under wet conditions

Answer

It assesses the organic matter content of fine aggregate

Answer

It determines the alkali-reactive silica content

Question 2

In the context of hot mix asphalt aggregate specifications, what does the sand equivalent (SE) value measure?

Accepted Answer

The relative proportion of clay-like material to sand-sized particles in fine aggregate

Answer

The percentage of fine aggregate passing the No. 200 sieve

Answer

The angularity of sand particles determined by uncompacted voids

Answer

The bulk specific gravity of combined fine and coarse aggregate blend

Question 3

The 10% fines value (TFV) test is an alternative to the aggregate crushing value and is particularly useful for evaluating which type of aggregate?

Accepted Answer

Weak or porous aggregates prone to crushing at lower loads

Answer

Dense crystalline rocks with high abrasion resistance

Answer

Lightweight expanded clay aggregates

Answer

Recycled concrete aggregates only

Question 4

Which standardized test method is used to evaluate the susceptibility of aggregates to polishing under traffic, relevant to skid resistance of asphalt pavements?

Accepted Answer

ASTM D3319 Accelerated Polishing Test (British Pendulum)

Answer

ASTM C131 Los Angeles Abrasion Test

Answer

ASTM C88 Sulfate Soundness Test

Answer

ASTM C1252 Uncompacted Void Content

Question 5

When evaluating recycled concrete aggregate (RCA) for structural concrete use, which property typically causes the most concern compared to virgin aggregate?

Accepted Answer

Higher absorption and lower specific gravity due to adhered mortar

Answer

High specific gravity values exceeding 3.0

Answer

Lower Los Angeles abrasion values

Answer

Reduced alkali reactivity potential

Question 6

In quality control testing of aggregate production, what is the purpose of running a combined gradation analysis for a blended aggregate stockpile?

Accepted Answer

To ensure the blended product meets the required particle size distribution specification

Answer

To verify the specific gravity of each aggregate fraction individually

Answer

To determine the organic content of the combined aggregate

Answer

To measure the abrasion resistance of the combined blend

Question 7

The Los Angeles abrasion and impact test (ASTM C131/C535) uses steel spheres as a charge. For coarse aggregate larger than 37.5 mm, which charge size and test method designation applies?

Accepted Answer

ASTM C535 with 12 steel spheres

Answer

ASTM C131 Method A with 6 steel spheres

Answer

ASTM C131 Method B with 8 steel spheres

Answer

ASTM C131 Method D with 4 steel spheres