Term
Design Principles (Walker, 1991) |
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Definition
1. Line 2. Form 3. Texture 4. Color
5. Variety
6. Repetition
7. Balance
8. Perception
9. Scale
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Term
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Definition
Asphalt -
A naturally-occurring constituent of most crude petroleum's.
- Strong adhesive
- Highly waterproof
- Solid or semi-solid at norm. temperatures
- Can be liquefied by applying heat or by dissolving it in petroleum solvents
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Term
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Definition
Asphalt cement-
Asphalt that is refined to meet specifications for paving, industrial, and special purposes.
- Free from water and coarse foreign material and containing less than one percent of ash
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Term
4 Types of Cutback Asphalt |
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Definition
4 Types of Cutback Asphalt
- Rapid Curing (RC)- Gasoline solvent, High volatility
- Medium Curing (MC)- Kerosene solvent, medium vol.
- Slow Curing (SC)- Oil, Low vol.
- Road Oil - A heavy petroleum oil, very slow curing
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Term
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Definition
Emulsified Asphalt-
An emulsion of asphalt and water.
When applied, the water evaporates, leaving the asphalt cement to perform its function.
Emulsions are used because they effectively reduce asphalt viscosity for lower temperature uses (tack coats, fog seals, slurry seals, bituminous surface treatments (BST), stabilization material).
Emulsions are typically either anionic (asphalt droplets are negatively charged) or cationic (asphalt particles are positively charged).
Emulsion ~ A mixture of two or more liquids that are normally immiscible (nonmixable or unblendable)
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Term
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Definition
Prime Coat-
An application of a low viscosity cutback asphalt to an absorbent surface such as crushed stone or gravel.
It is used to prepare the base course for an asphalt pavement.
the asphalt penetrates into the base, plugs the voids, hardens the top, and helps bind base material to the overlying asphalt pavement. |
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Term
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Definition
Tack Coat-
A light application of an emulsified asphalt used to ensure a bond betweeen two asphalt pavement courses. |
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Term
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Definition
Road Mix-
- An asphalt pavement mixture.
- Produced by mixing mineral aggregate and cutback or emulsified asphalt.
- Mixed at the site with special mixing equipment.
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Term
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Definition
Hot Mix Asphalt- (Asphalt pavement mixture)
- Produced at a central mixing facility
- Must be spread and compacted at an elevated temperature.
- Both aggregate & asphalt are heated prior to mixing
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Term
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Definition
Cold Mix Asphalt - (Asphalt pavement mixture)
- May be spread and compacted at a normal temperature
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Term
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Definition
Porous Asphalt -
- Consists of an open-graded asphalt-aggregate mix over an open-graded aggregate base.
- Open-graded mixtures contain aggregate that is essentially uniform in size
- Resulting pavement contains pores that allow stormwater to penetrate and be stored in the base material until it can infiltrate into the soil beneath.
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Term
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Definition
Lift -
The compressed depth of a layer of asphalt paving material installed in one application.
- (i.e. a 6" depth of paving may contain two 3" lifts)
- 4"-6" is usually max. depth of a lift.
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Term
Advantages of Asphalt Pavements |
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Definition
Advantages of Asphalt Pavements -
- Inexpensive for large areas
- Resistent to acids, alkalis, and salts
- Dark color reduces glare
- Can be recycled
- Can be used within hours of placement and compaction
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Term
Disadvantages of Asphalt Pavement |
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Definition
Disadvantages of Asphalt Pavement -
- Can be damaged by petroleum solvent spills
- Absorbs radiant energy producing higher air temps
- Tends to shift under high traffic loads, requiring a type of edge restraint
- Softens under high temps
- Susceptible to surface damage by sharp edged objects
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Term
Depth requirements for asphalt pavements |
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Definition
Depth requirements for asphalt pavements -
Depends upon-
- Anticipated traffic load
- Strength and bearing capacity of the subsoil
- Climatic conditions (frost penetration depth)
- Strength of aggregate materials
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Term
Geotextile fabrics role in asphalt pavement |
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Definition
Geotextile fabrics role in asphalt pavement -
Geotextile fabrics are sometimes used under asphalt pavements, particularly in locations with very fine textured low load bearing subsoil
The fabrics serve to isolate the aggregate base and assist with maintaining the integrity of the base. |
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Term
How many types of
portland cement
does ASTM C150 recognize? |
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Definition
How many types of
portland cement
does ASTM C150 recognize?
5
Type I - Normal general purpose
Type II - Moderate sulfate resistance
Type III - High early strength
Type IV - Low heat of hydration
Type V - High sulfate resistance |
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Term
Portland Cement (Concrete) |
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Definition
Portland Cement (Concrete) -
- High in compressive strength
- Low in tensile strength
- Compressive strength measured in psi after 28 days
- water to cement ratio heavily influences conc. strength
- Less water = stronger mix
- More water = improved workability
Slump test measures workability of mix and consistency between batches |
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Term
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Definition
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