Highway Pavement Aggregates

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What is the diameter range of gravels according to the classification?

4.75 to 75 mm (correct)

75 microns to 4.75 mm

4.75 to 300 mm

2 mm to 1 cm

What is the primary purpose of the sand equivalent test?

To analyze the diameter of aggregates

To determine the amounts of clays in aggregates (correct)

To evaluate the cleanliness of aggregates

To measure the hardness of aggregates

What happens to clay when it comes into contact with water?

It breaks down completely

It expands significantly (correct)

It shrinks significantly

It remains unchanged

What is the term for the process of aggregates breaking down during mixing and construction?

Degradation Signup and view all the answers

What is the purpose of the Los Angeles abrasion test?

To determine the aggregate toughness Signup and view all the answers

What is the primary cause of abrasive wear in pavements?

Traffic and loading Signup and view all the answers

What is the term for the absence of deleterious materials in aggregates?

Cleanliness Signup and view all the answers

Why do flat and elongated aggregate particles tend to fracture during compaction?

Because they orient themselves along the direction of compaction, inducing high stresses Signup and view all the answers

What is the effect of high absorption of asphalt binder by an aggregate?

It reduces the amount of asphalt binder available for film formation Signup and view all the answers

What is the purpose of measuring the aspect ratio of aggregate particles?

To measure the flatness and elongation of the particles Signup and view all the answers

What property of aggregate particles ensures a high degree of internal friction?

Angularity Signup and view all the answers

What happens when an aggregate is highly absorptive?

It continues to absorb asphalt binder after initial mixing Signup and view all the answers

What is the measurement method for coarse aggregate particles?

Counting the crushed faces on the aggregate particle Signup and view all the answers

What is the purpose of specifying control points for the gradation in Superpave?

To ensure enough air voids for asphalt binder expansion Signup and view all the answers

What is the main characteristic of Stone Matrix Asphalt (SMA)?

Load transfer by particle-to-particle contact of coarse aggregates only Signup and view all the answers

What is the minimum CBR value required for the subbase layer in freeways?

40% Signup and view all the answers

What is the maximum liquid limit allowed for the subgrade layer in freeways?

30% Signup and view all the answers

What is the requirement for fine aggregates passing sieve No 40 in the base layer?

Liquid limit and plasticity index should be less than 25% and 6%, respectively Signup and view all the answers

What is the requirement for the percentage of aggregate with one crushed face in the asphalt layer?

At least 50% Signup and view all the answers

What is the purpose of specifying a restricted zone in the gradation?

To prevent dense particle-to-particle contacts with a lubricating effect Signup and view all the answers

What is the minimum compaction degree required for the subgrade layer in freeways?

98% Signup and view all the answers

What is the type of asphalt mixture used for high permeability and noise reduction?

Open graded Signup and view all the answers