26.3.5. Voids in mineral aggregate VMA

Try these first

1. 1.

   What does VMA stand for?

   Hint

   Look for the abbreviation commonly used in asphalt design.

2. 2.

   What is included in the calculation of VMA?

   Hint

   Think about what elements in the asphalt mix are 'voids'.

3. 3.

   What does VMA help determine in asphalt mix design?

   • Strength of the mix
   • Amount of void space
   • Color of the asphalt

   Hint

   Consider what VMA literally stands for.

4. 4.

   True or False: A high VMA contributes to insufficient performance of asphalt.

   • True
   • False

   Hint

   Reflect on moderation in performance characteristics.

5. 5.

   If an asphalt mix has 5% air voids and 16% bitumen, calculate the VMA and discuss implications if it were reduced to 3% air voids.

   Hint

   Consider what happens to VMA if air voids decrease.

6. 6.

   Discuss how the balance of VMA could influence the lifecycle of a newly laid asphalt roadway under heavy traffic conditions.

   Hint

   Reflect on the performance under stress and the role of VMA.