PAVING ASPHALTSOrigins, properties, manufacture and use
PAVING ASPHALTSOrigins, properties, manufacture and use
Dr. Ludo Zanzotto
Bituminous Materials Chair
Faculty of Engineering
University of Calgary
May 2001
Dr. Ludo Zanzotto
Bituminous Materials Chair
Faculty of Engineering
University of Calgary
May 2001
Historical BackgroundHistorical Background
One of the oldest engineering materials “asphaltos” - sticky, firm - Greek “jatu-krit - pitch creating - Latin: “pixtumen” Use:
– Sumerians (3000 B.C.) - building purposes– Egyptians (2500 B.C.) - “mumyia” - mummy– Biblical times (2500 - 1500 B.C.)
• Noah’s ark - waterproofing
• Tower of Babel - mortar
• Paving
Sources and Manufacture of AsphaltSources and Manufacture of Asphalt
Sources– natural asphalt– crude oil
Asphalt manufacture– distillation - oxidation– extraction - modification– cracking processes
Paving asphalt represents 3 ~ 4 % of the total annual crude oil throughput in USA and Canada
Yield of Asphalt from Different Yield of Asphalt from Different Crude OilsCrude Oils
API DegreesSP.Gravity% Sulfur
BOSCANVENEZUELA
10.1.9996.4
ARABIANHEAVY
28.2.8862.8
NIGERIALIGHT38.1.8340.2
36
7
26
58
21
14
10
28
27
33
20
16
30
1
GasolineKerosene
Lt. Gas Oil
Hv. Gas Oils
BitumenResiduum
Vol. %
Useage of AsphaltUseage of Asphalt
Canadian market (1999).... 3.75 millions of t/year USA market (1999)............38.00 millions of t/year World market................~ 130.00 millions of t/year
80 ~ 90 % of asphalts are used in pavements 10 ~ 20 % of asphalts are used in roofing,
waterproofing and for other purposes
World: 2.0 ~ 2.5 billions t/year of asphalt paving mixes
Potential Asphalt Production from Potential Asphalt Production from Heavy Oils in Western CanadaHeavy Oils in Western Canada
Recoverable heavy oil in Western Canada: 3.5 ~ 7.0 billions of tons
Potential production of asphalt: 1600 ~ 2800 millions of tons
Price of asphalt in USA (spring 2001): US $ 100 ~ 150/t
Price of asphalt in Canada (spring 2001): US $ 150 ~ 180/t
Value of Western Canadian Asphalt: US $ 160 ~ 420 billion
Total Existing Length of Roads and Total Existing Length of Roads and Streets in USAStreets in USA
Total Mileage6,243,000 kilometers (3,880,000 miles)
Paved Mileage *3,466,000 kilometers (2,154,000 miles)
* 94% asphalt surfaced
Total Existing Mileage of Roads and Streets in U.S.A.
Portland Cement Concrete 200,000 kms (124,000 miles)
Earth 603,000 kms (375,000 miles)
Gravel or similar 2,174,000 kms (1,351,000 miles)
Asphalt 3,267,000 kms (2,030,000 miles)
Source: Federal High Administration
Number of Refineries MarketingNumber of Refineries MarketingPaving Asphalt in USA and CanadaPaving Asphalt in USA and Canada
Crude Oil Throughput in US and Crude Oil Throughput in US and Canadian RefineriesCanadian Refineries
0
10
20
30
40
Nu
mb
er
of
Re
fin
eri
es
<5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-50
Throughput (10,000 bpd)
Paving Asphalt Production Capacity Paving Asphalt Production Capacity of US and Canadian Refineriesof US and Canadian Refineries
0
2
4
6
8
10
12
14
Nu
mb
er
of
Re
fin
eri
es
<5 5-7.5 7.5-10 10-20 20-30 30-40 40-50 50-60 >60
Asphalt Production Capacity (100 tpd)
Composition and Structure of AsphaltComposition and Structure of Asphalt
Physical and chemical character of asphalt is determined by:– composition of crude oil– method of crude oil and asphalt processing
Asphalt: complex, multicomponent, colloidal system
Asphalt is composed of a multitude species which differ by:– molecular mass, chemical structure, polarity
Molecular mass between 400 - 3000 D Carbon skeleton: 25 - 150 atoms
Composition and Structure of Asphalt (Cont’d)Composition and Structure of Asphalt (Cont’d)
Composition varies considerably among asphalts manufactured from different crude oils
The largest portion of paving asphalts are produced as vacuum residues with the cut point between 425°C and 565°C
Relatively small difference in elemental analysis– C: 80.0 ~ 85.0 %– H: 7.8 ~ 8.3 %– S: 1.0 ~ 7.0 %– O: 2.7 ~ 5.0 %
Composition and Structure of Asphalt (Cont’d)Composition and Structure of Asphalt (Cont’d)
Group composition:– saturates– naphthene aromatics– polar aromatics– asphaltenes
Composition and Structure of Asphalt (Cont’d)Composition and Structure of Asphalt (Cont’d)
Hypothetical structure of asphaltene
Composition and Structure of Asphalt (Cont’d)Composition and Structure of Asphalt (Cont’d)
Unit sheet mass: 1 000 - 4 000 D
Cluster or particle mass: 4 000 - 10 000 D
Micelle mass: 40 000 - 40 000 000 D
Properties of AsphaltProperties of Asphalt
Critical conditions during construction and service– Construction:
• mixing
• spreading appropriate viscosity
• compacting
– Service:
• plastic deformation (rutting)
• thermal cracking
• fatigue cracking
• water sensibility
Properties of Asphalt (Cont’d)Properties of Asphalt (Cont’d)
-50 0 50 100 150
T [°C]
Consistency Consistency
Flexibility
Flexibility Resistance todeformation
Mixing
Resistanceto deformation
Loading Tim e [s]10
-s10
10
IDEAL BEHAVIO UR
-50 0 50 100 150
T [°C]
Consistency Consistency
Loading Tim e [s]10 -s 1010
Too brittle Too brittle
Too soft
Too soft
REAL BEHAVIO UR
Specifications of Paving AsphaltsSpecifications of Paving Asphalts
The role of specifications:– specify properties that directly reflect asphalt
behaviour– express these properties in physical units– provide limits for those properties to exclude
poor performing products– provide information from which the service
performance can be predicted Important properties of asphalt:
– mechanical– adhesive– durability
Specifications of Paving Asphalts (Cont’d)Specifications of Paving Asphalts (Cont’d)
Conventional tests used for asphalt characterization:– penetration, ductility, softening point R&B, flash
point, spot test, Fraass breaking point….. Ageing characteristics:
– Thin Film Oven Test, Rolling Thin Film Oven Test, Pressure Aging Vessel…
Rheological tests:– Bending Beam Rheometer, Direct tension Test,
Dynamic Shear Rheometer
Specifications of Paving Asphalts (Cont’d)Specifications of Paving Asphalts (Cont’d)
Beginning of specifications - around 1900 Classification of asphalts for commercial
purposes in the first half of the century - exclusively conventional tests
First: grading test - penetration at 25°C 1960’s in USA: grading test - viscosity at 60°C Canada: hybrid - penetration/viscosity 1990’s in USA : Superpave specification
(“performance related”)
Classical Penetration- Based Classical Penetration- Based SpecificationSpecification
Min Max Min Max Min Max Min Max Min Max
Penetration @ 77°F(25°C) 100g, 5s 40 50 60 70 85 100 120 150 200 300
Flash Point, °F (Cleveland open cup) 450 --- 450 --- 450 --- 425 --- 350 ---
Ductility at 77°F (25°C) 5cm/min, cm 100 --- 100 --- 100 --- 100 --- 100A ---
Solubility in trichloroethylene, % 99 --- 99 --- 99 --- 99 --- 99 ---
Retained penetration after thin-film 55+ --- 52+ --- 47+ --- 42+ --- 37+ ---oven test, %
Ductility at 77°F (25°C) 5cm/min, cm --- --- 50 --- 75 --- 100 --- 100A ---after thin-film oven test
40-50 60-70 85-100 120-150 200-300
Penetration Grade
REQUIREMENTS FOR ASPHALT CEMENT FOR USE IN PAVEMENT CONSTRUCTIONASTM D946
A If ductility at 77°F (25°C) is less than 100 cm, material will be accepted if ductility at 60°F (15.5°C) is 100 cm minimum at the pull rate of 5 cm/min
Viscosity-Based SpecificationViscosity-Based Specification
AC-2.5 AC-5 AC-10 AC-20 AC-40
Viscosity, 140°F (60°C), P 250 ± 50 50 ± 100 1000 ± 200 2000 ± 400 4000 ± 800
Viscosity, 275°F (135°C), min, cSt 80 110 150 210 300
Penetration, 77°F (25°C), 100g, 5s, min 200 120 70 40 20
Flash point, Cleveland open cup, min, °F (°C) 325 (163) 350 (177) 425 (219) 450 (232) 450 (232)
Solubility in trichloroethylene, min, % 99 99 99 99 99
Tests on residue from thin-film oven test:
Viscosity, 140°F (60°C), max, P 1250 2500 5000 10,000 20,000 Ductility, 77°F (25°C), 5 cm/min, min, cm 100A 100 50 20 10
VISCOSITY GRADE
REQUIREMENTS FOR ASPHALT CEMENT, VISCOSITY GRADED AT 140°F (60°C)ASTM D3381
Note: Grading based on original asphalt
A If ductility is less than 100, material will be accepted if ductility at 60°F (15.5°C) is 100 minimum at a pull rate of 5 cm/min
Canadian Federal SpecificationCanadian Federal Specification
Penetration at 25°C [dmm]
Canadian Federal Specification (Cont’d)Canadian Federal Specification (Cont’d)
Canadian Federal Specification (Cont’d)Canadian Federal Specification (Cont’d)
Grades
Requirements
Penetration at 25°C100g and 5s, 0.1mm
*Viscosity at 60°C, Pa.s or*Viscosity at 135°C, mm2/s
*Group A
*Group B
*Group C
Flash Point (Cleveland Open Cup), °C
Thin-film oven test, % loss in mass
Penetration of residue at 25°C, 100g, 5s, 0.1mm, % of original penetration
Solubility in trichloro-ethylene, % by mass
60-70
Min Max
60 70
80-100
Min Max
80 100
120-150
Min Max
120 150
150-200
Min Max
150 200
200-300
Min Max
200 300
300-400
Min Max
300 400
Test MethodASTM
D 5
D 2171
D 2170
User must specify either Figure 1 or Figure 2 for all asphalt grades. Both figures shall not be used simultaneously
230 ---
--- 0.8
52 ---
99 ---
230 ---
--- 0.85
47 ---
99 ---
User must specify either Figure 1 or Figure 2 for all asphalt grades. Both figures shall not be used simultaneously
220 ---
--- 1.3
42 ---
99 ---
220 ---
--- 1.3
40 ---
99 ---
175 ---
--- 1.5
37 ---
99 ---
175 ---
--- 1.5
35 ---
99 ---
D 92
D 1754
D 2042
GRADES OF ASPHALT CEMENT
* All requirements, except for viscosity at 60°C or at 135°C, are the same for Group A, B and C. Minimum viscosity is defined by the bottom line ofeach group as shown in Figure 1 or 2.
Superpave SpecificationSuperpave Specification
Strategic Highway Research Program:– established by US Congress in 1987 as a five-
year, $ 150 million research program to improve the performance and durability of roads in USA
Outcome:– asphalt binder performance related specification
• uses modern physical tests
• weather related
• traffic related
Superpave Specification (Cont’d)Superpave Specification (Cont’d)
Unlike older go - no go specifications Superpave specification determines different levels of asphalt quality
The minimum quality needed for the particular road is also determined
Presently already used in all states in USA (modification in California)
Introduced in Ontario and Quebec Sooner or later will be used across Canada
Superpave Specification (Cont’d)Superpave Specification (Cont’d)
Further developments:– Asphalt binder Expert Task Group (ETG) under
the auspices of Transportation Research Board (US Academy of Sciences) and Federal Highway Administration
– development of parameters and testing methods better related to service performance
– ultimately: development of damage weighted performance models
Superpave Specification (Cont’d)Superpave Specification (Cont’d)
Superpave specification attempts to measure properties that are directly related to pavement field performance
Handling Pump
Permanent Deformation
FatigueCracking
ThermalCracking
Flow
Rutting
Structural Cracking
Low Temp Cracking
Rotational Viscometer
Dynamic Shear Rheometer
Bending Beam RheometerDirect Tension Tester
TEST EQUIPMENTPERFORMANCE PROPERTY
Dynamic Mechanical Analysis by Dynamic Mechanical Analysis by Dynamic Shear RheometerDynamic Shear Rheometer
Stiffness and m-value by Bending Stiffness and m-value by Bending Beam RheometerBeam Rheometer
Tensile Strength and T Critical by Tensile Strength and T Critical by Direct Tension TesterDirect Tension Tester
Superpave Asphalt Binder GradesSuperpave Asphalt Binder Grades
High Temperature Grades(Degrees C)
PG46
PG52
PG58
PG64
PG70
PG76
PG82
Low Temperature Grades(Degrees C)
-34, -40, -46
-10, -16, -22, -28, -34, -40, -46
-16, -22, -28, -34, -40
-10, -16, -22, -28, -34, -40
-10, -16, -22, -28, -34, -40
-10, -16, -22, -28, -34
-10, -16, -22, -28, -34
Performance Graded Asphalt Binder Performance Graded Asphalt Binder Specification Specification
Performance Grade PG46 PG52 PG58-34 -40 -46 -10 -16 -22 -28 -34 -40 -46 -16 -22 -28 -34 -40
Average 7-day Max PavementDesign Temperature, °C <46 <52 <58Minimum PavementDesign Temperature, °C >-34 >-40 >-46 >-10>-16>-22>-28>-34>-40>-46 >-16>-22>-28>-34>-40
ORIGINAL BINDERFlash Point Temp, T48: Min °C 230Viscosity, ASTM D 4402: Max, 3 Pa.s (3000 cP) Test Temp, °C 135Dynamic Shear, TP5: G*/sin , Min, 1.00 kPa Test temp@10 rad/s, °C 46 52 58
ROLLING THIN FILM OVEN (T240) OR THIN FILM OVEN (T179) RESIDUEMass Loss, Maximum, % 1.00Dynamic Shear, TP5: G*/sin , Min, 2.20 kPa Test temp@10 rad/s, °C 46 52 58
PRESSURE AGING VESSEL RESIDUE (PP1)PAV Aging Temp, °C 90 90 100Dynamic Shear, TP5: G*/sin , Min, 5000 kPa Test temp@10 rad/s, °C 10 7 4 25 22 19 16 13 10 7 25 22 19 16 13Physical Hardening REPORTCreep Stiffness, TP1: S, Max, 300 MPa m-value, Min, 0.300 Test Temp, @ 60s, °C -24 -30 -36 0 -6 -12 -18 -24 -30 -36 -6 -12 -18 -24 -30Direct Tension, TP3: Failure Strain, Min, 1.0% Test Temp@ 1.0mm/min, °C -24 -30 -36 0 -6 -12 -18 -24 -30 -36 -6 -12 -18 -24 -30
PG64-10 -16 -22 -28 -34 -40
<61
>-10 >-16 >-22 >-28 >-34 >-40
64
64
100
31 28 25 22 19 16
0 -6 -12 -18 -24 -30
0 -6 -12 -18 -24 -30
Performance Grade PG46 PG52 PG58-34 -40 -46 -10 -16 -22 -28 -34 -40 -46 -16 -22 -28 -34 -40
Average 7-day Max PavementDesign Temperature, °C <46 <52 <58Minimum PavementDesign Temperature, °C >-34 >-40 >-46 >-10>-16>-22>-28>-34>-40>-46 >-16>-22>-28>-34>-40
Flash Point Temp, T48: Min °C 230Viscosity, ASTM D 4402: Max, 3 Pa.s (3000 cP) Test Temp, °C 135Dynamic Shear, TP5: G*/sin , Min, 1.00 kPa Test temp@10 rad/s, °C 46 52 58
Mass Loss, Maximum, % 1.00Dynamic Shear, TP5: G*/sin , Min, 2.20 kPa Test temp@10 rad/s, °C 46 52 58
PAV Aging Temp, °C 90 90 100Dynamic Shear, TP5: G*/sin , Min, 5000 kPa Test temp@10 rad/s, °C 10 7 4 25 22 19 16 13 10 7 25 22 19 16 13Physical Hardening REPORTCreep Stiffness, TP1: S, Max, 300 MPa m-value, Min, 0.300 Test Temp, @ 60s, °C -24 -30 -36 0 -6 -12 -18 -24 -30 -36 -6 -12 -18 -24 -30Direct Tension, TP3: Failure Strain, Min, 1.0% Test Temp@ 1.0mm/min, °C -24 -30 -36 0 -6 -12 -18 -24 -30 -36 -6 -12 -18 -24 -30
Performance Graded Asphalt Binder Specification Performance Graded Asphalt Binder Specification (Cont’d)(Cont’d)
Performance Grade PG70 PG76 PG82-10 -16 -22 -28 -34 -40 -10 -16 -22 -28 -34 -10 -16 -22 -28 -34
Average 7-day Max PavementDesign Temperature, °C <70 <76 <82Minimum PavementDesign Temperature, °C >-10 >-16 >-22 >-28 >-34 >-40 >-10 >-16 >-22 >-28 >-34 >-10 >-16 >-22 >-28 >-34
ORIGINAL BINDERFlash Point Temp, T48: Min °C 230Viscosity, ASTM D 4402: Max, 3 Pa.s (3000 cP) Test Temp, °C 135Dynamic Shear, TP5: G*/sin , Min, 1.00 kPa Test temp@10 rad/s, °C 70 76 82
ROLLING THIN FILM OVEN (T240) OR THIN FILM OVEN (T179) RESIDUEMass Loss, Maximum, % 1.00Dynamic Shear, TP5: G*/sin , Min, 2.20 kPa Test temp@10 rad/s, °C 70 76 82
PRESSURE AGING VESSEL RESIDUE (PP1)PAV Aging Temp, °C 100(110) 100(110) 100(110)Dynamic Shear, TP5: G*/sin , Min, 5000 kPa Test temp@10 rad/s, °C 34 31 28 25 22 19 37 34 31 28 22 40 37 34 31 28Physical Hardening REPORTCreep Stiffness, TP1: S, Max, 300 MPa m-value, Min, 0.300 Test Temp, @ 60s, °C 0 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 0 -6 -12 -18 -24Direct Tension, TP3: Failure Strain, Min, 1.0% Test Temp@ 1.0mm/min, °C 0 -6 -12 -18 -24 -30 0 -6 -12 -18 -24 0 -6 -12 -18 -24
Superpave PG Grades of Asphalts Superpave PG Grades of Asphalts From Selected Crude OilsFrom Selected Crude Oils
Asphalt CGSB Pen T OfficialGrade 25°C High Low PG Grade
Cold Lake 80/100A 80 64.6 -27.5 92.1 64-22100 62.4 -29.1 91.5 58-28
Bow Valley 80/100A 80 63.1 -24.8 87.9 58-22100 60.9 -26.7 87.6 58-22
Redwater 80/100B 80 59.7 -25.5 85.2 58-22100 57.8 -26.2 84.0 52-22
Foster Creek 80 63.7 -26.6 90.3 58-22100 61.5 -28.2 89.7 58-28
Cold Lake 120/150A 120 60.5 -30.5 91.0 58-28150 58.1 -32.2 90.3 58-28
Bow Valley 120/150A 120 59.0 -28.3 87.3 58-28150 57.7 -30.2 87.9 52-28
Redwater 120/150B 120 56.1 -27.0 83.1 52-22150 54.0 -28.2 82.2 52-28
Foster Creek 120 59.7 -29.5 89.2 58-28150 57.3 -31.2 88.5 52-28
Cold Lake 150/200A 150 58.1 -32.2 90.3 58-28200 54.8 -34.1 88.9 52-34
Bow Valley 150/200A 150 57.7 -30.2 87.9 52-28200 53.5 -32.5 86.0 52-28
Redwater 150/200B 150 54.0 -28.2 82.2 52-28200 51.2 -29.7 80.9 --
Foster Creek 150 57.3 -31.2 88.5 52-28200 54.2 -33.4 87.6 52-28
Service Temperature [°C]
Superpave PG Grades of Asphalts From Selected Superpave PG Grades of Asphalts From Selected Crude Oils Crude Oils (Cont’d)(Cont’d)
Asphalt CGSB Pen T Official
Grade 25°C High Low PG Grade
Cold Lake 200/300A 200 54.8 -34.1 88.9 52-34
300 49.8 -36.1 85.9 46-34
Bow Valley 200/300B 200 53.5 -32.5 86.0 52-28
300 48.6 -35.0 83.6 46-34
Redwater 200/300C 200 51.2 -29.7 80.9 --
300 47.0 -31.7 78.7 --
Foster Creek 200 54.2 -33.4 87.6 52-28
300 49.4 -36.5 85.9 52-34
Cold Lake 300/400A 300 49.8 -36.1 85.9 46-34
400 46.0 -37.2 83.2 46-34
Bow Valley 200/300B 300 48.6 -35.0 83.6 46-34
400 44.9 -36.4 81.3 --
Redwater 300/400C 300 47.0 -31.7 78.7 --
400 43.7 -32.9 76.6 --
Foster Creek 300 49.4 -36.5 85.9 52-34
400 45.8 -38.8 84.6 46-34
`
Service Temperature [°C]
ConclusionsConclusions
Paving asphalt - important international commodity
Alberta - vast reserves of high quality paving asphalt
New US asphalt specification recognizes the difference in product quality
Strong demand for higher quality material Opportunity to export asphalt as a final material
or as heavy crude oil with enhanced value of its distillation residue