7.2.3. Toughness

Try these first

1. 1.

   Define toughness in the context of aggregates.

   Hint

   Think about how materials withstand sudden forces.

2. 2.

   What does a suitable Aggregate Impact Value indicate for surface courses?

   Hint

   Relate it to the performance of pavements.

3. 3.

   What is toughness in aggregates?

   • Resistance to abrasion
   • Resistance to impact
   • Resistance to chemical attack

   Hint

   Think about what affects pavement performance the most.

4. 4.

   True or False: A lower Aggregate Impact Value is better for surface courses.

   • True
   • False

   Hint

   Consider the relation of the value to pavement longevity.

5. 5.

   You are tasked with selecting aggregates for a new highway. The project demands high durability due to heavy traffic. How would you evaluate the toughness of the aggregates you're considering?

   Hint

   Consider combining tests to validate your aggregate choice.

6. 6.

   Discuss the long-term implications for a pavement built with aggregates that have an unacceptably high Aggregate Impact Value. What kind of maintenance might be required?

   Hint

   Relate your answer to economic factors in construction.