Yongjoo Kim Senior Researcher
Highway Pavement Research DivisionKorea Institute of Construction Technology
Development and Application of Polymer-Modified Warm-Mix Asphalt Technology Cus-
tomized for Mongolia Road Condition
2nd International Mongolia Road Expo & ConferenceMarch 21-22, 2014., Buyant-Ukhaa Sport’s Palace
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Content
Polymer-Modified Warm-Mix Asphalt (PWMA)Polymer-Modified Warm-Mix Asphalt (PWMA)
Pavement Conditions in MongoliaPavement Conditions in Mongolia
Field Applications of PWAM Customized for Mongolian Road Condition
Development of PWAM Customized for Mongolian Road ConditionDevelopment of PWAM Customized for Mongolian Road Condition
Conclusions
3
KICT Activity in Mongolia
KICT is collaborating with MRT, MRA, UB, ESTO to contribute to improve Mongolian road condition
MOU Technical Sup-port Training
5
Key Factors of Building Good Asphalt Pavement
If anyone wants to build good pavement, you should consider the following four key factors.
Material Selec-tion Mix Design Production Construction
High quality and consistent materi-als should be se-lected based on the standard specifica-tion.
Bitumen & Aggregate
Paving and compact-ing process should be proceed with proper temperature.
Mixing and produc-ing temperatures should be controlled accurately at as-phalt plant.
Design Aggregate Structure
Design Binder Content
Laboratory mix de-sign and perfor-mance tests should be conducted at well equipped labo-ratory.
6
Causes of Early Failures in Mongolian Road
1. Traffic Loading
Base and Subbase
2. Environment Loading
3. Inappropriate Materials 4. No Quality Control of Pavement Construction
7
Ulaanbaatar City Road
7
Stripping
Construction Joint
Thermal Crack
Surface Layer
Base Layer
Crushed Aggregate
Intermediate Layer
Base Layer
Crushed Aggregate
Surface Layer
18cm
4cm
3cm
5cm
6cm
15cm
30cm
Mongolia Korea
Too thin asphalt layer leads to create crack faster and other distress
Bad Smoothness
9
Polymer-Modified Asphalt
9
Polymer-modified asphalt coats aggregates to en-hance adhesion
AggregateAggregate
Asphalt Polymer
+ +
Aggregate
Polymer-Modified Asphalt Mixture
=
Polymer-Modified Asphalt
Polymer
Asphalt
Polymer-modified asphalt is a composition of bitumen and polymer
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Polymer-Modified Asphalt Covers Wide Range of Tem-perature
0 10 20 30 40 50 60-10-20-30-40 70 80
PG 58-28
PG 70-34
Unmodified Bitumen
Polymer-Modified Asphalt
This is the benefit of the Polymer
Temperature ºC
-50
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Roles of Polymer-Modified Asphalt Pavement
Plastic Deformation (Rutting)
Low Temperature Crack-ing Heavy Traffic Condition Cold Weather Condition
PMA Pavement leads to
Increasing pavement life
1) Improve rutting resistance
2) Reduce fatigue cracking
3) Mitigate thermal cracking
4) Resist top-down cracking
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Considerations of Using Polymer-Modified Asphalt Mixture
Warm-mix asphalt technology can reduce producing and compacting temperature of polymer-modified asphalt mix-ture to maintain its workabil-ity and compactability
Polymer-Modified Asphalt Polymer-Modified Asphalt (PMA) mixture should be produced at 170˚C to 190˚C and compacted at 140˚C to 160˚C be-cause of maintaining mixture’s workabil-ity and compactability.※ If appropriate temperatures are not
achieved, well coating aggregate and required field density are not guaran-teed
Polymer-Modified Asphalt
Unmodified As-phalt
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Warm-Mix Asphalt Technology
180°C
160°C
140°C
120°C
100°C
80°C
WMA technology allows the mixing, paving, and compaction of asphalt mixes at significantly lower temperatures (30˚C) than conventional HMA
ProductionTemperature
ConstructionTemperature
ProductionTemperature
ConstructionTemperature
180°C
160°C
140°C
120°C
100°C
80°C
Hot-Mix Asphalt Pavement Warm-Mix Asphalt Pavement
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Benefits of Warm-Mix Asphalt
By decreased production, and compaction tempera-tures, we have many benefits
WARM WARM
HOT HOT
Production Process
1. Saving Energy2. Reducing Emissions
Paving Process
1. Better workability and compactability
2. Extending Constriction Period
3. Early Traffic Open
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Reduction of Traffic Open Time
Temperature vs. Time
WMA Pavement5 hrs 20 min
HMA Pavement7 hrs 30 min
Early Site Open(Lead to save indirect cost)
Tem
pera
ture
(C
)
Time (min)
Temperature Monitoring
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Extension of Compaction Temperature of Warm-Mix As-phalt Pavements
200°C 180°C 160°C 140°C 120°C 100°C 80°C 60°C 40°C 20°C
1st 2nd 3rdHot-Mix Asphalt
Warm-Mix Asphalt
1st Com-
paction
2nd
Compaction
3rd Com-
paction
Not com-pactable
1st 2nd 3rd Not com-pactable
WMA provides longer compaction time
WMA provides longer construction pe-riod
Better workability and comapctabil-
ity
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Extension of Paving Construction Period in Cold Region
1 2 3 4 5 6 7 8 9 10 11
Hot-Mix Asphalt Pavement
Warm-Mix Asphalt Pavement
Current Period of Road Construction in Mongolia (6 months)
Changed Period of Road Construction in Mongolia (7.5 months)
WMA technology would extend construction period, about 2 months in Mongolia, WMA mixtures are still workable and com-pactable at low temperatures.
Extended period of road construction will encourage to build more roads in Mongolia
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LEADCAP WMA Technology
LEADCAP Family
LEADCAP-B (Base)
LEADCAP-M (Modified)
LEADCAP-A(Advanced)
In 2009, the Korea Institute of Construction Technology (KICT) and Kumho Petrochemical, Ltd. developed a new warm-mix as-phalt technology.
Named “Low Energy and Low Carbon-Dioxide Asphalt Pavement (LEADCAP)”
LEADCAP is an additive of a wax-based composition including a crystal controller and an adhe-sion promoter.
Easy to reduce viscosity of bitumen to be compacted at warm temperature
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Why We Should Use Polymer-Modified Warm-Mix Asphalt (PWMA) Pavement in Mongolia
Heavy TrafficLow temperature
Thermal Crack
Construction Defect
Rutting Overall Damage
Traffic Loading
Base and Subbase
Environment Loading Quality Control &Quality Assurance
Polymer Modified Asphalt (PMA) Warm-Mix Asphalt
SBS (Styrene-Butadiene-Styrene Block Copolymer) Rubber : Elastic recovery properties
Wax based composi-tion
Low viscosity
Improve rutting resistance Mitigate thermal cracking Manage temperatures
Build durable and long life pavement in cold region
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Development of Polymer-Modified Warm-Mix Asphalt (PWMA) Customized for Mongolian Weather and Traffic Conditions
Improving engineer-ing properties, par-ticularly, crack resis-tance at low tempera-ture and rutting re-sistance at high tem-perature
Improving workabil-ity
Providing better compaction on the road and the ability to haul paving mix for longer distance
Extending the paving season by be-ing able to pave at lower temperature
PMA
WMA
Polymer + LEADCAP
LEADCAP WMA additive
N2 Polymer N4 Polymer
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Ductility and Viscosity Results
Ductility Viscosity
2.8
1.91.7
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Stright Asphalt WMA PMA-N2 WMA PMA-N4
Rota
tion
al
vis
cosit
y
@ 1
35
ºC
(P
a.s
)
Type of Asphalt Binder
The rotational viscosity of WMA PMA-N2 and WMA PMA-N4 de-creases about 0.9Pa.s to 1.1Pa.s compared to straight asphalt.
It is good indicator of effectiveness of WMA additive to reduce the vis-cosity of polymer-modified asphalt at 135 ºC
7.9
25.2
29.8
0
5
10
15
20
25
30
35
Stright Asphalt WMA PMA-N2 WMA PMA-N4
Du
cti
lity
(cm
)
Type of Asphalt Binder
The ductility of WMA PMA-N2 and WMA PMA-N4 increases about 17.3cm to 21.9 ºC compared to straight asphalt.
It indicates that WMA PMA would be more flexible than straight as-phalt at room temperature.
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PG & Flexibility at Low Temperature
Performance Grade
PG 58-28
PG 70-34
Unmodified Bitumen
WARM PMA Bi-tumen
58
2834
70
Low
Tem
p.
Hig
h T
em
p.
Flexibility
Forc
e
(MP
a)
Deformation (mm)
Cold Bending Test
①
②
작성확인승인
시료번호시편크기무게최대하중굽힘강도최대변위
b×h () ㎟gNd () ㎜kPaMPa
-1519.83×20.0648.4384.405.785.771.2164.706994.884.77
-15-119.97×20.4648.28297.104.274.461.1963.435300.173.59
-15-219.78×20.5848.57326.604.684.901.1561.245625.284.07
Avr.336.034.915.041.1863.125973.444.14
작성 확인 승인
시료번호 시편크기 최대하중 굽힘강도 최대변위
b×h ( )㎟ N d ( )㎜ kPa MPa
-15 20.83×19.93 415.80 6.03 6.24 0.05 2.69 314.58 119.55
-15-1 19.97×19.93 502.10 7.60 7.53 0.09 4.88 689.13 83.02
-15-2 19.91×19.89 353.00 5.38 5.30 0.05 2.58 256.15 111.17
Avr. 423.63 6.33 6.35 0.06 3.38 419.95 104.58
: 2011-04-08시험일자 : 시험장소
: 제 조 처 : 채취장소
: 기준신율
① Unmodified Bitumen
② PWMA Bitumen
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Field Application of PWMA Pavement in Mongo-lia
2012 2013
UKHAA KHUDAG –GASHUUN SUKHAIT
South Gobi Road
Ulaanbaatar City Road
Ulaanbaatar City Road
Project Site
Project Site
Project Site
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Mix Design Results and Cross Section
UlaanbaatarSouth Gobi
OAC(%) Air Void(%)
HMA(Unmodified asphalt)
5.2 4.3
WMA (LEADCAP) 5.2 4.0
PWMA 5.4 3.8
OAC(%) Air Void(%)
HMA(Unmodified asphalt)
5.2 4.3
PWMA-1 5.2 4.0
PWMA-2 5.4 3.8
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Field Trials of PWMA Pavement in South Gobi Road in 2012
HMA PWMA-1 PWMA-2
Gmm (g/㎤ ) 2.505 2.492 2.499
Core Density (g/㎤ ) 2.267 2.295 2.305
Air Voids (%) 9.5 7.9 7.8
Condition Information
Weather Condition 2012.09 (Fall)
Mix Type 19mm Dense-Graded Asphalt
Additive Type-1 PWMA -1
Additive Type-2 PWMA-2
Mixing Type with LEADCAP Plant-mixed
Mixing Temp. 150±5˚C (PWMA-1)155±5˚C (PWMA-2)
Compaction Temp. 140±5˚C (PWMA-1)145±5˚C (PWMA-2)
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Field Trials of PWMA Pavement in Ulaanbaatar City Road in 2012
Condition Information
Weather Condition 2012.09 (Fall)
Mix Type 13mm Dense-Graded Asphalt
Additive Type-1 WMA(LEADCAP)
Additive Type-2 PWMA(PMA+LEADCAP)
Mixing Type Plant-mixed
Mixing Temperature 140±5˚C (WMA)150±5˚C (PWMA)
Compaction Tempera-ture
130±5˚C (WMA)140±5˚C (PWMA)
HMA WMA WMA PMA
Gmm (g/㎤ ) 2.388 2.443 2.437
Core Density (g/
㎤ )2.344 2.341 2.382
Air Voids (%) 1.8 4.1 2.5
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Field Trials of PWMA Pavement in Ulaanbaatar City Road in 2013
Condition Information
Weather Condition 2013.09 (Fall)
Mix Type 13mm Dense-Graded Asphalt
Additive Type-2 PWMA(STE-M3)
Mixing Type Plant-mixed
Mixing Temperature 150±5˚C (PWMA)
Compaction Tempera-ture 140±5˚C (PWMA)
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Conclusions
1. Early distresses, such as cracks and rutting, have occurred from Mongolian pavements due to heavy traffic, severe weather condition and inappropriate quality control of paving construction.
2. Polymer-modified warm-mix asphalt(PWMA) is selected to enhance rutting and crack resistances at high and low temperatures.
3. Polymer-modified warm-mix asphalt(PWMA) is selected to reduce the mixing and compacting temperatures and to provide better com-paction on the road and ability to haul paving mix for longer dis-tances.
4. The PWMA field trials were successfully completed in South Gobi road and Ulaanbaatar road.
5. Field experiences confirmed that PWMA is effective to produce and compact asphalt mixture at temperature of 20°C lower than conven-tional PMA mixture.
6. Long-term performance and durability of PWMA pavements should be monitored and researched further.
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‘NOTHING’ is not an Option
Polymer-Modified Warm-Mix Asphalt (PWMA) Pavement will leads to improve road condition in Mongolia
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