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

4

1st International Mongolia Road Expo & Conference

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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

8

South Gobi Road

Heavy Traffic

No QA/QC

Cold Weather

Early Failure after1 year Service Life

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

10

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

11

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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Polymer-Modified WMA Pavement Successfully Debut in Mongolia in 2012

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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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Quality Control with KICT Researchers

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Training and Technical Know-How Transfer

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Everyone is Smiling because We Successfully Built New PWMA Pavement in Mongolia

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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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Thank You

2nd International Mongolia Road Expo & ConferenceMarch 21-22, 2014., Buyant-Ukhaa Sport’s Palace

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