29. Binder Specifications

Question 1

Grading

Answer 1

Three systems: penetration grading, viscosity grading, performance grading

Question 2

Penetration grading

Answer 2

The less viscous the asphalt, the deeper the needle goes.
High penetration is ‘soft’, used in cold climates, while low penetration is ‘hard’, used in warm climates

Question 3

Penetration grading advantages

Answer 3

Easy, done at average service temp (25C)

Question 4

Penetration grading disadvantages

Answer 4

Empirical test, doesn’t provide guidance on mixing or compaction temperatures

Question 5

Viscosity grading

Answer 5

More fundamental, asphalts with similar results have similar rutting performance, better guidance available for mixing and compaction temperatures

Question 6

Viscosity grading advantages

Answer 6

Fundamental material property, done at max service temp, includes high & average temperature criteria

Question 7

Viscosity grading disadvantages

Answer 7

Harder to run, doesn’t address long-term aging, doesn’t consider low-temp cracking

Question 8

Performance grading (PG)

Answer 8

AKA: Superpave performance grading
Measures specific asphalt binder properties tied to field performance
Involves climate conditions and aging considerations

Question 9

PG 58 - 28

Answer 9

PG - performance grade
58 - degrees C, average 7 day max pavement temp
- 28 - degrees C, min pavement temp (1 day)
The higher the second number, the softer the asphalt

Question 10

What form of asphalt has the highest flash point?

Answer 10

Hard asphalt

Question 11

What two items are needed to choose concrete type?

Answer 11

Summer and winter temperatures