1. Line
2. Form
3. Texture
4. Color

5. Variety

6. Repetition

7. Balance

8. Perception

9. Scale

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

Asphalt cement

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

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

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)

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.

Tack Coat-

A light application of an emulsified asphalt used to ensure a bond betweeen two asphalt pavement courses.

Road Mix-

• An asphalt pavement mixture.
• Produced by mixing mineral aggregate and cutback or emulsified asphalt.
• Mixed at the site with special mixing equipment.

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

Cold Mix Asphalt - (Asphalt pavement mixture)

• May be spread and compacted at a normal temperature

Porous Asphalt -

• Consists of an open-graded asphalt-aggregate mix over an open-graded aggregate base.

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.

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

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 

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

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.

How many types of

portland cement

does ASTM C150 recognize?

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

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