Asphalt Paving Materials

Chapter 6

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Bituminous Materials

BituminousMaterials

NaturalAsphalts

PetroleumAsphalts

Tar &Pitch

(late 1800s) (1900s)(early 1900s)

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Natural Asphalt

Rock Asphalt Native AsphaltAsphalt Sand

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Rock Asphalt

Rock Asphalt

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ROCK ASPHALT & OIL SHALE IN KENTUCKY

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Asphalt Sands

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Asphalt Sands

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Asphalt Sands

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Native Asphalt

La Brea Tar Pits

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Native Asphalt

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Source: Geological Society of Trinidad and Tobago (www.gstt.org)

Native Asphalt

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Native Asphalt

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http://www.flickr.com/photos/striderv/4314238332/lightbox/

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Native Asphalt

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Native Asphalt

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Bituminous Materials

BituminousMaterials

NaturalAsphalts

PetroleumAsphalts

Tar &Pitch

(late 1800s) (1900s)(early 1900s)

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Chickamauga Coking Ovens

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Dunlap, TN Coking Ovens

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Bituminous Materials

BituminousMaterials

NaturalAsphalts

PetroleumAsphalts

Tar &Pitch

(late 1800s) (1900s)(early 1900s)

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Crude Oil ChemistryOils (Hydrocarbons)

Resin-coated asphaltenes

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Crude Oil

AromaticHydrocarbons (oils)

SaturatedHydrocarbons

Light Crude Heavy Crude

“oils”“oils”

“oils”

“oils”

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Petroleum Distillation

TubeHeater

Bitumen Residuum38-70 Carbons

Crude

DistillationColumn

Diesel Oil15-38 Carbons

Kerosene10-14 Carbons

Naphtha5-10 Carbons

Gasoline1-4 Carbons

Butane & Propane1-4 Carbons

550ºC

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Crude Oil

33

20

16

30

58

67

26

21

14

10

28

27

BitumenResiduum

GasolineKerosene

Lt. Gas Oil

Hv. Gas Oil

BoscanVenezuela

ArabianHeavy

NigeriaLight

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Liquefying Asphalt CementAsphalt Cement

(Bitumen Residuum)

Heatit

Suspendit in water

Thin it withsolvents

Hot-MixAsphalt

Temperature-Viscosity

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Peanut Butter

Ketchup

Chocolate Syrup

Honey

Tomato Juice

Vegetable Oil AASHTO T-245 MARSHALL MIXING TEMP. RANGE (170 +/- 20 cSt)

AASHTO T-245 MARSHALL COMPACTING TEMP. RANGE (280 +/- 30 cSt)

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Liquefying Asphalt CementAsphalt Cement

(Bitumen Residuum)

Heatit

Suspendit in water

Thin it withsolvents

Hot-MixAsphalt

CutbackAsphalt

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Cutback (Liquid) Asphalt

Rapid Curing (RC)Asphalt cement thinned with gasoline or naphthaUsed for tack and seal coats (surface applications)

Medium Curing (MC)Asphalt cement thinned with keroseneUsed for prime coats, cold-laid pavement bases

Slow Curing (SC)Asphalt cement thinned with diesel oil or gas oilsUsed for cold-laid pavement bases

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Incr

easi

ng T

hick

ness

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Cutback (Liquid) Asphalt

30

30-60

70

70-140

250

250-500

800

800-1600

3000

3000-6000

Solvent

Asphalt

Grade

Kinematic Viscosity@ 140°F (CS)

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Liquefying Asphalt CementAsphalt Cement

(Bitumen Residuum)

Heatit

Suspendit in water

Thin it withsolvents

Hot-MixAsphalt

EmulsifiedAsphalt

CutbackAsphalt

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Emulsified AsphaltWater & emulsifying agent

5-10 micron spheres of asphalt

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Emulsified Asphalt

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Emulsified Asphalt

LIMESTO

NE

SILICA

Anionic Emulsifier Cationic Emulsifier

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Emulsified Asphalt

Rapid Setting (RS or CRS)Used for surface coats, penetration macadam

Medium Setting (MS or CMS)Used for open-graded asphalt-treated base

Slow Setting (SS or CSS)Used for dense-graded asphalt-treated base

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