Background

Asphalt Tar– Soluble in petroleum

products– Generally a by-

product of petroleum distillation process

– Can be naturally

– Resistant to petroleum products

– Generally by-product of coke (from coal) production

Can be naturally occurring

Petroleum-Based AsphaltsAsphalt is waste product from refinery processing of crude oil– Sometimes called the “bottom of the barrel”Sometimes called the bottom of the barrel

Properties depend on:– Refinery operations– Composition crude source-dependent

GasolineNaphthaKerosene

Diesel

Motor OilsLube Oil

Asphalt

Barrel of Crude Oil

Asphalt Cement Components

Asphaltenes– Large, discrete solid inclusions (black)

Hi h i it t– High viscosity component

Resins– Semi-solid or solid at room temperature

» Fluid when heated» Brittle when cold

Oils– Colorless liquid– Soluble in most solvents– Allows asphalt to flow

Refinery Operation

LIGHT DISTILLATE

FIELD STORAGEPUMPINGSTATION

HEAVY DISTILLATE

PROCESSUNIT

TOWERDISTILLATIONREFINERY

RESIDUUM

MEDIUM DISTILLATE

UNIT

ASPHALTCEMENTS

FOR PROCESSING INTOEMULSIFIED ANDCUTBACK ASPHALTS

STILL

AIR

AIRBLOWNASPHALT

STORAGE OR

GAS

PETROLEUM

SAND AND WATER

CONDENSERS AND

COOLERS

TUBEHEATER

Types

Asphalt cementsGenerally refinery produced material– Generally refinery produced material

– Air blown asphalt cements Cutbacks– Asphalt cements “cut” with petroleum solvents

Emulsions– Mixture of asphalt cement, water, and emulsifyingMixture of asphalt cement, water, and emulsifying

agent

Air Blown Asphalt Cement

Cutbacks

Rapid cure (RC) (Naphtha or Gasoline)Hi h l tilit f l t– High volatility of solvent

– Tack coats, surface treatmentsMedium cure (MC) (Kerosene)– Moderate volatility– Stockpile patching mix

Slow cure (SC) (Low viscosity oil)Slow cure (SC) (Low viscosity oil)– Low volatility– Prime coat, dust control

Emulsions

Emulsifier gives surface charge to asphalt droplets suspended in water medium– Anionic

» Negative charge» Alkaline» Good with limestones (positive charge)

– Cationic » Positive charge» Positive charge» Acid» Good with silica gravels (negative charge)

Hot

Cold recycling

Bitumen

Water Air

Foamed Bitumen

2 - 3% cold water injected into the hot bitumen will produce foam with an expansion of 10 to 20 times of the original volume

Purchasing of Asphalt Cements

Need to be able to specify desirable characteristicscharacteristics“Desirable characteristics” have evolved over time and with increasing technological advances

Purchasing requires specificationsPurchasing requires specifications

Early Specifications

Lake AsphaltsAppearance– Appearance

– Solubility in carbon disulfidePetroleum asphalts (early 1900’s)– Consistency

»Chewing»Penetration machine

- Measure consistency

Penetration TestingSewing machine needleSpecified load, time, temperature

100 g Penetration in 0.1 mm

Initial After 5 seconds

Penetration Specification

Five Grades• 40 - 50• 60 - 70• 85 - 100• 120 150• 120 - 150• 200 - 300

Viscosity Graded Specifications

Viscosity: the ratio between the applied shear stress and the rate of shear

Definition

stress and the rate of shear.

η = τ / γ

Types of Viscosity Tubes

Asphalt Institute TubeZietfuchs Cross-Arm

Tube

Testing

Absolute viscosityU-shaped tube with– U-shaped tube with timing marks & filled with asphalt

– Placed in 60C bath– Vacuum used to pull

asphalt through tube– Time to pass marks– Viscosity in Pa s (Poise)

40

Penetration GradesAC 40

100)

AR 16000

50

6070

85100

120150

AC 20

AC 10

AC 5

AC 2 5

100

50

osity

, 60C

(140

F) AR 8000

AR 4000

AR 2000

150200300

AC 2.510

5

Visc

o AR 1000

Short Term Binder AgingRolling Thin Film Oven

– Simulates aging from hot mixing and construction

ControlFan

1.3. 9Air jet

Bottle carriage

Penetration0 sec 5 sec

Viscosityvacuum

100g 100g

5 secPenetration

1 .1. 17

AC OR AR

hard

Consistency(pen or viscosity)

Pen limitViscosity limit

soft

A

CB

Viscosity limit

Lower viscosity limit

-15 25 60 135Temperature, C

3- 60/70 AC Asphalts meeting specs

1 .1. 18

SUPERPAVE

-20 20 60 135Pavement Temperature, C

ViscosityWorkability

RuttingFatigueCracking

1.3. 3

FreshFresh&

RTFO

PAVPAV

Rotational Viscometer (Brookfield)

Torque Motor

Inner Cylinder

Thermosel Environmental

Chamber

Digital Temperature Controller

101055

Viscosity, Pa sViscosity, Pa s

Mixing/Compaction Temps

..22

..33

..55

11

Compaction RangeMixing Range

..11100100 110110 120120 130130 140140 150150 160160 170170 180180 190190 200200

Temperature, CTemperature, C

Mixing Range

SUPERPAVE

-20 20 60 135Pavement Temperature, C

ViscosityWorkability

RuttingFatigueCracking

1.3. 3

FreshFresh&

RTFO

PAVPAV

Short Term Binder AgingRolling Thin Film Oven

– Simulates aging from hot mixing and construction

ControlFan

1.3. 9Air jet

Bottle carriage

Rack of individual pans(50g of asphalt / pan)

Pressure Aging Vessel

Bottom of pressure aging

vessel

Vessel Lid Components1.3. 19

Motor

Area for

Parallel Plates

Liquid Bath

SUPERPAVE

-20 20 60 135Pavement Temperature, C

ViscosityWorkability

RuttingFatigueCracking

1.3. 3

FreshFresh&

RTFO

PAVPAV

C l d

Deflection Transducer

Air BearingControl andData Acquisition

Asphalt Beam

Air Bearing

Load CellFluid Bath

LoadingFrameSupports

TemperatureDetector

Bending Beam Rheometer Equipment

Fluid BathFluid BathLoading

Ram

Cooling System

Direct Tension Test

Courtesy of FHWA

SUPERPAVE

-20 20 60 135Pavement Temperature, C

ViscosityWorkability

RuttingFatigueCracking

1.3. 3

FreshFresh&

RTFO

PAVPAV

Superpave Asphalt Binder Specification

The grading system is based on Climate

PG 70 10PG 70 - 10

Performance Grade

Min pavement temperature

Grade

Average 7-day max pavement temperature

Binder Selection & Tests

Select GradePG 76 10

verify GradeG* δ S PG-64-22

• climate• reliability

PG-76-10PG-70-10

• G*, δ, S, m, etc.• temp/vis. profile

G 6

KUWAIT

DHAHRAN

AL-QAISUMAH

AL-WAJH

TABOUKTABOUK R.

BURAYDAH

HAIL

HAIL R.

RAFHANORTH BORDER R.

AL-JAWF

AL-JAWF R.

AL-QURAYYATTURAIF

ARAR

AL-QURAYYAT R.

QATAR

O M A N

U A E

EASTERN PROVINCE

HAFUF

RIYADH

RIYADH REGION

SULAYYIL

ASIR R

BISHABAHA

AL-BAHA R.TAIF

MAKKAHJEDDAH

YANBUMADINAH

MADINAH R.

MAKKAH R.

AL-DAWADMI

BURAYDAH

AL-QASSIM R.

PG 70 - 10

PG 70 - 10

PG 64 - 10 PG 76 - 10

O M A N

NAJRAN R.

NAJRAN SHARURAH

JIZAN

ABHA

JIZAN R.

ASIR R.

KHAMISMUSHAYT

Tentative Temperature Zoning for Asphalt Binder Specifications for the Gulf Countries.

Questions - ?