7.2.6. Specific Gravity and Water Absorption

Try these first

1. 1.

   Define specific gravity in your own words.

   Hint

   Think about how it relates to water.

2. 2.

   What is an acceptable value for water absorption?

   Hint

   Remember the limit we discussed in class.

3. 3.

   What does specific gravity measure?

   • Density of an aggregate
   • Weight of an aggregate
   • Volume of an aggregate

   Hint

   Think about what density compares to.

4. 4.

   True or False: Water absorption can affect bitumen adhesion.

   • True
   • False

   Hint

   Relate this to moisture effects in asphalt.

5. 5.

   You have two aggregates, Aggregate A (SG 2.8, WA 1.5%) and Aggregate B (SG 2.4, WA 2.5%). Which would be preferable for a high-strength concrete mix? Justify your decision.

   Hint

   Compare the attributes of both aggregates.

6. 6.

   A contractor wants to use an aggregate with water absorption above the acceptable limit for a surface layer in asphalt. Discuss the potential risks.

   Hint

   Think about long-term effects on pavement durability.