6. Road Aggregates – Requirements and Types

Try these first

1. 1.

   What does the Aggregate Crushing Value (ACV) measure?

   Hint

   Consider the performance of aggregates under heavy loads.

2. 2.

   What is the maximum allowable water absorption percentage for road aggregates?

   Hint

   Think about how much moisture the aggregate can tolerate.

3. 3.

   What is the maximum allowable Aggregate Crushing Value (ACV) for wearing surfaces?

   • 30%
   • 40%
   • 20%

   Hint

   Remember that lower values indicate better strength.

4. 4.

   True or False: Flakiness Index must be less than 15% for surface courses.

   • True
   • False

   Hint

   Think about the requirement for aggregate shape.

5. 5.

   Given that a new pavement requires aggregates with a maximum AIV of 25% and an ACV of 35%, list the types of aggregates that best suit this requirement and justify your reasoning based on their properties.

   Hint

   Consider aggregates with both high strength and minimal impact.

6. 6.

   A project specifies that a mix must have a Flakiness Index above 25% for economic reasons, but the structure calls for high durability. How can you address these conflicting requirements?

   Hint

   Think about mixing different types of aggregates to satisfy the performance while adhering to budget constraints.