Post on 14-Aug-2021
Lime in AsphaltLime Association of Texas Workshop
H t TXHouston, TX April 9, 2014p
1
Outline Background Types of Distress Benefits of Lime Summary
Long Life Pavement( i if )(5 to 40 Years Increase in Life)
Minimize Premature Pavement Distress
Minimize Rehabilitation and Maintenance
Minimize User Inconvenience (Customer Focused Construction)
Todays Technology/Materials/Contractors
Safe Driving Surface
Design Considerationsg
SafetyThicknessMixture
Safetyy
Work Zone Surface Propertiesp
– Friction– DrainageDrainage– Splash and Spray– Noise– Noise
Thickness Design Fatigue Limit S l t Mi t f Diff t D th i Select Mixture for Different Depth in
Pavement Structure
Friction/Splash/Spray/Noise Permanent deformation Thermal cracking Water Susceptibility
Stiffnessh / High RAP/RAS
Permanent deformation
Fatigue resistance Water susceptibility
MIXTURE DESIGN
Mixture design test parameters use for structuralDESIGN parameters use for structural design input
Designs for different traffic Designs for different traffic level and climates
Specific mixtures for different Specific mixtures for different layers in pavement
N i l i t Nominal maximum aggregate size
P f l d Proper use of recycled materials
b l b d Lab mix-lab compacted vsplant mix-field compacted
Mixture/Structural Design
StiffnessStiffness
Rutting
F ti Fatigue
Thermal cracking
Water susceptibility
Agingg g
Lab mix-lab compacted vsplant mix-field compactedplant mix field compacted
Recycled MaterialsRecycled Materials
RAP/RAS binder stiffness RAP/RAS binder stiffness Uniformity of RAP/RAS Cracking-fatigue,
thermal, reflection Aging
Lime in Asphalt
Several states require lime in all asphalt q pmixtures 5 10% of all asphalt mixtures contain lime 5-10% of all asphalt mixtures contain lime 150,000 tons of lime used in asphalt
mixture per year
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Summary-Design
Safe surfaces-friction, drainage, splash-ispray, noise
Specific mixtures for different layers Proper use of recycled materials
Outline Background
T f Di Types of Distress Benefits of Lime Summary
Pavement Performance Problems
Raveling Bleeding/Flushing
Transverse Cracking Longitudinal CrackingBleeding/Flushing
Rutting/Shoving Alli C ki
Longitudinal Cracking Reflection Cracking L li d Di Alligator Cracking Localized Distress
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RavelingRaveling
15
Raveling
16
Bleeding
17
Bleeding
18
Permanent Deformation
High T, Large Load, S i d/Sl L di (L )
19
Sustained/Slow Loading (Large t)Decreases w/Aging
Rutting and Shoving
20
ShovingShoving
21
Fatigue Cracking
22
Fatigue Cracking
23
Fatigue Crackingg g
Intermediate T, Repeated Loading, Fast
24
Loading (Small t)Increases w/Aging
Thermal Crackingg
L T L T R id L di (S ll t)25
Low T, Large T, Rapid Loading (Small t)Increases w/Aging
ThermalThermal Cracking
26
Longitudinal Crackingg g
27
Joint Reflective CrackingPavement Distress - Types
Joint Reflective Cracking
28
StrippingStripping
29
Patchingg
30
CrackCrack Sealing
31
Outline Background T f Di t Types of Distress
Benefits of Lime Summary
Benefits of Using LimeBenefits of Using Lime
Red ce Water S sceptibilitReduce Water SusceptibilityReduce AgingReduce Aging Increase Stiffness of MixtureReduce Plastic Index
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Loss of BondLoss of BondLoss of Strength
Water sensitivity Water susceptibility StrippingStripping
34
StrippingStripping
Loss of adhesionLoss of adhesion between aggregate surface and asphalt cement in thecement in the presence of
i tmoisture
35
Stripping Potential Controlled by:Stripping Potential Controlled by:
Asphalt cement properties Asphalt cement properties Aggregate properties Mixture characteristics Climate Traffic Construction practices Construction practices Pavement design
id ticonsideration36
Asphalt Cement PropertiesAsphalt Cement Properties
Physical propertiesPhysical properties Viscosity T t Temperature Adhesive ability Chemical properties
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Aggregate PropertiesAggregate Properties
Shape and surface textureShape and surface texture Gradation Fi t t & ti Fines content & properties Coating Absorption Surface chemistrySurface chemistry
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Mixture CharacteristicsMixture Characteristics
Asphalt cement contentAsphalt cement content Aggregate gradation Ai id t t Air voids content Strength
39
Hot-WetHot Wet
Southeast USSoutheast US High temperature-low viscosity Moisture in summer Bleeding Blistering
40
Cold-DryCold Dry
Freeze-Thaw CyclesFreeze Thaw Cycles Several days of moisture D il f h l Daily freeze-thaw cycles Water expansion Brittle asphalt
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TrafficTraffic
V l ADT Volume – ADT Heavy vehicles
42
Construction PracticesConstruction Practices
Quality controlQuality control Compaction - air voids J i t d it & ti Joint density & segregation Time of year
43
Water
44
Water
Fabric Chip Seal
Water45
Water
Water
Water
46
Water Susceptibility Water sensitivity Stripping Water damage Loss of Strength in the presence of
moisture– Adhesion between asphalt binder and
aggregategg g– Loss of strength in asphalt binder
47
Anti Strip AgentsAnti-Strip Agents
Liquids amines/di amines Liquids-amines/di-amines Solids-lime/portland cement/by-
products
48
Antistrip AdditivesLiquid Antistrip Agents
Chemical Compounds Containing Amines (Basic Chemical Compounds Containing Amines (Basic Compounds Derived from Ammonia)
Heat Stability
0 5 % Generally0.5 % Generally
May Change AC Properties (Soften)
Heat AC, Add Liquid Antistrip, Mix for 2 Min
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Antistrip AdditivesLime
Hydrated Lime - Ca(OH)Hydrated Lime Ca(OH) Bonding of the Calcium with the Silicates in
A tAggregate And/or Interaction or Modification of the Acidic
Portions of AC 1 to 1.5% Generally1 to 1.5% Generally Dry Mixed w/ Hot Aggregate or Damp Aggregate
Immediately before AC Added and MixedImmediately before AC Added and Mixed 50
Water Sensitivity TestsWater Sensitivity-Tests
Boil Test (ASTM D3625)(Tex-503-C) Immersion Compression (ASTM D1075)Immersion Compression (ASTM D1075) Tensile Strength Ratio (AASHTO T 283) Hamburg (Tex-242-F)
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TSR and Hamburg
AASHTO T283AASHTO T283 Modified LottmanTest (TSR)– 1 Freeze-Thaw
(F/T) Cycle
Resilient Modulus Test (MR)
b Hamburg Wheel-Tracking Device (HWTT)52
Resilient Modulus Test ResultsUniversity of Nevada Reno StudyUniversity of Nevada, Reno Study
Resilient Modulus 77F (Ksi)
250
300Truckee, CA Grass Valley, CA
150
200
Before
100
150 Lottman
After Lotmann
0
50
0 1 2 0 1 2
53Percent Hydrated Lime (%)
Resilient Modulus Test ResultsUniversity of Nevada Reno StudyUniversity of Nevada, Reno Study
Resilient Modulus 77F (Ksi)400
( )
Mammoth, CA Moreno, CA
300
Before
100
200 Lottman
After Lotmann
0
100 Lotmann
00 1 2 0 1 2
54Percent Hydrated Lime (%)
Types of Lime Added to Dry AggregateUniversity of Nevada Reno StudyUniversity of Nevada, Reno Study
Resilient Modulus 77F (Ksi)
400
500
( )
300
400
200
Before Lottman
After
0
100Lotmann
0Control Hyd. Lime I Hyd. Lime II Quicklime Dolomitic
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Deeth ReconstructionState of Nevada Test Results
500
State of Nevada Test ResultsResilient Modulus (KSI)
300
400 Original
200
300 Vacuum SaturatedLottman
0
100
0No PCC, 5.5% FA, 5.5% AC
1.5 % PCC, 5.5% AC
1.5% PCC, 3.0% FA, 6.0% AC
2.0% PCC, 2.5% FA, 6.0% AC6.0% AC 6.0% AC
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Water Sensitivityy
After asphalt chemistry After asphalt chemistry After aggregate surface chemistry After coatings
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After Aggregate Surface
CA++Asphalt
CA++Asphalt
CA++
CA++
Initial coating Long term coating
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Long term coating Adhesion cohesion
Hamburg Test Results (Nebraska Study)
0B1_1.0% Screenings-1st PairB1_1.0% Screenings-2nd PairB1_1.0% Screenings-AverageB2 1.0% Dry Lime-1st Pair
-4
n (m
m)
B2_1.0% Dry Lime 1st PairB2_1.0% Dry Lime-2nd PairB2_1.0% Dry Lime-AverageB3_1.0% Lime Slurry-1st PairB3_1.0% Lime Slurry-2nd PairB3 1 0% Lime Slurry-Average
-8
Impr
essi
on
B3_1.0% Lime Slurry Average
B1 Stripping Point approx. 1,800 passes
-12
Max
imum
B2 Stripping Point approx. 4,300 passes
B3 Stripping Point approx. 2,200 passes
-16
papp o , 00 passes
0 1000 2000 3000 4000 5000 6000 7000 8000
No. of Passes
Moisture Sensitivity Dynamic Modulus (E*)
Un-Treated_UnagedLi id t t d U d
Un-Treated_UnagedLi id t t d U d0H
z,ks
i
0Hz,
ksi
Liquid-treated_UnagedLime-treated_Unaged
Liquid-treated_UnagedLime-treated_Unaged
104
F an
d 10
104
F an
d 10
odul
us E
*at
odul
us E
*at
60
CaliforniaTexas
Dyna
mic
Mo
Dyna
mic
Mo
Number of F-T Cycles Number of F-T Cycles
...But without Embrittlement at Low Temperature
70/100 + mixed filler w/ 40% lime70/100 + limestone filler
Temperature
No 70/100 + limestone filler70/100
No negativeeffect on cracking
ess
(Pa)
Beneficialeffect on
cracking
Stif
fne rutting
70/100 bitumen versus temperature
data from Wortelboeret al. (ESHA/LCPC),
E&E 1996
APA (under Water) Test Results24
B0_No AdditiveB1_1.0% ScreeningsB2_1.0% Dry LimeB3 1 0% Lime Slurry (Concentration Ratio = 0 33)
16
20
)
B3_1.0% Lime Slurry (Concentration Ratio 0.33)B4_1.0% Lime Slurry (Concentration Ratio = 0.22)B5_1.0% Lime Slurry (Concentration Ratio = 0.13)
APA Rutting Failure
12
16
epth
(mm
)
Criteria
8Rut
De
0
4
00 1000 2000 3000 4000 5000 6000 7000 8000
Strokes
Mechanisms: Filler Effect on Softening Point90
ratu
re C 90
80Hydrated LimeLimestoneGraywacke
ng T
empe
r
70
60
Graywacke
all S
ofte
nin 60
50
ng a
nd B
a
40
30
Hydrated lime added to the bitumen has a substantially greater
Rin 0 10 20 30 40 50 60 70 80
Filler Content (wt. %)
Hydrated lime added to the bitumen has a substantially greater impact in reducing the softening point of asphalt binder than does filler from graywacke or limestone source. Why?
Aging IndexWestern Research Institute
0% 10% 20%Log Aging Index
Western Research Institute
2.5
30% 10% 20%
2
1
1.5
0
0.5
0Boscan Ca. Central W. Texas Maya N. Slope Mays
64
Additive Effect on the Hardening of AsphaltUt h DOT Fi ld St d
6000Viscosity – Stokes at 140F
Utah DOT – Field Study
5000
6000
3000
4000
2000
3000
No Additive
0
1000HydratedLime
0 1 2 3 4 5 6 7 8Time in Years
Hydrated Lime Improves Mixture Stiffness at HighMixture Stiffness at High
TemperatureStiffening effect = better rutting resistance
12
8
10
(%)
rut depth of AC 14
data from 4
6
rut d
epth
LCPC 1999
0
2
10 100 1 000 10 000 100 00010 100 1,000 10,000 100,000loading cycles
AC 14 35/50 AC 14 35/50 + 1.25% lime
Comparison of Fatigue Life1.0
AAD-1 AAM-1 AAD-1+HL AAD-1+LS AAM-1+HL
%)
Nf = A(strain)-B
Stra
in (%
S
0.11.E+03 1.E+04 1.E+05
Fatigue life
Resistance to Thermal CrackingThermal Stress Restrained Specimen (TSRST)
0 F T 6 F TState Mix
0 F-T 6 F-T
Fracture Stress (psi)
Fracture Temp (C)
Fracture Stress (psi)
Fracture Temp (C)
U d 368 24 333 24
AL
Un-treated 368 -24 333 -24
Liquid-treated 345 -26 304 -29
Lime-treated 406 -24 424 -27
CA
Un-treated 303 -10 210 -11
Liquid-treated 329 -11 300 -17
Lime-treated 404 -13 381 -13Lime treated 404 13 381 13
IL
Un-treated 375 -13 232 -16
Liquid-treated 275 -14 251 -16
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Lime-treated 426 -18 377 -16
Resistance to Thermal Crackingh l i d i ( )Thermal Stress Restrained Specimen (TSRST)
(Cont’d)
0 F T 6 F TState Mix
0 F-T 6 F-T
Fracture Stress (psi)
Fracture Temp (C)
Fracture Stress (psi)
Fracture Temp (C)
U d 292 19 126 25
SC
Un-treated 292 -19 126 -25
Liquid-treated 268 -17 229 -28
Lime-treated 311 -17 198 -15
TX
Un-treated 287 -19 210 -20
Liquid-treated 277 -19 235 -20
Lime-treated 353 -17 377 -18Lime treated 353 17 377 18
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OUTLINE Background T f Di t Types of Distress Benefits of Lime
Summary
Summary
Improve Performance Improve Performance Balance Pavement Thickness Design and
Mi D iMixture Design Lime offers some help
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Pavement Distress Lime Benefits
• Reduce AgingRaveling • Reduce Aging• Improved Resistance to Water
Bleeding • Increased Stiffness• Improved Resistance to Water
Rutting • Increased Stiffness• Improved Resistance to WaterImproved Resistance to Water
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Pavement Distress Lime Benefits
• Increased StiffnessFatigue Cracking • Increased Stiffness• Improved Resistance to Water
Thermal Cracking • Aging
Reflective Cracking • AgingReflective Cracking • Aging
Stripping • Improved Resistance to WaterI d Stiffpp g • Increased Stiffness
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