Pavement Material 3 Flashcards
(14 cards)
Pavement type:
Flexible pavement and rigid pavement
What is the typical Section of a flexible pavement
- Surface Course
2.Base Course - Subbase
- Subgrade
What is hot mix asphalt/ asphalt concrete?
Classified as a flexible pavement because the structure deflects under loading
Composed of several layers of material. Each layer receives the loads from the above layer, spreads them out, then passes on the next layer below
What is wearing surface course
Layer in contact load with traffic loads and normally contains highest quality materials
Provided, friction, smoothness, noise control, rut and shoving resistance and drainage
What is base course ?
Beneath the surface course. Provides additional load distribution and contributes to drainage and frost resistance . Constructed out of aggregate and HMA
What is a Subbase?
Course between base and subgrade
Functions as structural support minimise intrusion fines, frost damage and provide a working platforms.
The placement of granular subbase and base course can be undertaken by either what?
Grader or mechanical spreader
What is compaction of material
Compaction is to reduced voids content, increase strength, bearing capacity and reduce compressibility
What are the two critical factors that control the compaction process?
The moisture content and particle distribution of the materials
State SIX aggregate characteristics that are of interest to the roading engineers.
Aggregates for use in asphalt mixes or sprayed seals should be:
Sound and durable
Well shaped
Clean and consistently graded
Resistant to polishing
Properties dependant on source
Toughness
Soundness
Density
Porosity (water absorption)
Resistance to polishing
Affinity for bitumen
Aggregates controlled by Properties
Shape
Particle size distribution
Cleanliness
What is aggregate test
