7.3.4. Shape Tests

Try these first

1. 1.

   What does the Flakiness Index measure?

   Hint

   Think about how thickness is categorized.

2. 2.

   What does the Elongation Index evaluate?

   Hint

   Consider the relationship of length compared to the mean sieve size.

3. 3.

   What is the purpose of the Flakiness Index?

   • To measure density
   • To measure flaky particles
   • To evaluate toughness

   Hint

   Think about what flakiness refers to.

4. 4.

   True or False: A combined index of 40% is acceptable for bituminous mixes.

   • True
   • False

   Hint

   Recall the acceptable limits we discussed.

5. 5.

   You have an aggregate sample with a Flakiness Index of 18% and an Elongation Index of 25%. Is the combined index acceptable for use in a pavement mix? Show calculations.

   Hint

   Add both indices to check against the requirement.

6. 6.

   If a construction project requires aggregates with specific indices, how would you adjust a sample with 60% flaky particles to meet the 35% combined index requirement?

   Hint

   Consider how you would compose a new mix.