Asian Bitumen Conference , Nov 2011 Singapore , Presentation by Benzene International Pte Ltd, on Modified Bitumen and the trends

By NARAYANAN ELLANGO B.Eng, M.Sc (Eng)
www.benzeneinternational.com

ARGUS ASIAN BITUMEN 2011
SINGAPORE

Benzene International Pte Ltd, Singapore

POLYMER MODIFIED BITUMEN AN INTRODUCTION:
SIMPLY BITUMEN + MODIFIER = MODIFIED BITUMEN
Developments in the manufacturing process of Polymer Modified Bitumen (PMB) are constantly increasing
the end performance of road and asphalt surfaces. Modified Bitumen has been used for over 30 years and
was introduced in the 80’s. Manufactures are continually striving to improve the performance through
tighter quality controls and advanced manufacturing processes employed. Many local authorities now
recommend the use of a minimum of 10% modified bitumen which results in longer lasting roads with better
performance.

A well-engineered binder can be the determining whether a bitumen product will perform under the rigours
of modern day traffic conditions.

Through research and calculated statistics of increased overall traffic volumes, tire pressures, heavy axle
loadings, speed of traffic, environmental and climate changes and concerns, have demanded innovative road
construction designs and materials to be utilised.

Polymers were introduced to bitumen to modify its original behaviour. They type and quantity of polymer
added, the based bitumen binder used and the production technique used will greatly influence the end
performance characteristics of the modified bitumen produced. A balance between the viscosity and elastics
properties of a binder, can be found, controlled and achieved by using the correct base bitumen and
polymer.


WHAT ARE POLYMERS?
DEFINITION: Any of numerous natural and synthetic compounds of usually high
molecular weight consisting of up to millions of repeated linked units, each a relatively
light and simple molecule.

•Very large molecules

•Made up of smaller monomers

•Common both in nature and everyday life

•First synthetic polymers created around 1910

•Varying molecules and lengths


KRATON POLYMERS
The main grades used in bitumen applications are:

Kraton D1184 polymer and KRATON D 1186 polymer are the industry benchmark polymers
Kraton D1101 polymer for exceptional low temperature performance
Kraton G1650 polymer for those applications that require outstanding heat and oxidation
resistance such as hot mopping asphalt binders.
Kraton D1118 polymer for improved flow of self-adhesive products
Kraton D polymer based on isoprene for increased tack in self-adhesive products, also at low
temperatures.

HIGH SHEAR MIXERS
High shear mixers grind the polymer while immersed in the bitumen. The polymer is mixed
into the bitumen and passed through the high shear mixer, to cut the particles into small
pieces. The size of the pieces is influenced by the gap width between the stator and the
rotor. Decreasing size, increases the specific surface area, speeding up the absorption of
the oily components in the bitumen.

The absorption of oily components softens the polymer particles, and allows shear forces
in the high shear mixer to tear and stretch these particles, further increasing the specific
surface area. Eventually this should result in a homogeneous dispersion of the polymer
throughout the bitumen.


ADVANTAGES OF USING MODIFIED BITUMEN:
•Higher Resistance to Deformation at High Temperature
•Enhanced Deformation Resistance to Low Temperature Cracking
•Improved Temperature Susceptibility
•Improved Aging Resistance
•Improved Adhesion between Aggregate and Binder
•Higher Fatigue Life of Mixes
•Delay in Thermal / Reflective Cracking
•Over all Extended Pavement Surface Life
•Savings in Total Road Life Costing.
•Improved Binder Film Thickness
•Improved Cohesion
•Improved Workability
•Improved Fuel Resistance
•Improved Water Resistance
•Not detrimental to basic properties of Bitumen and Enhances them.


EFFECT OF POLYMERS
1.00E+08

1.00E+07

1.00E+06

1.00E+05
MODULUS

1.00E+04

1.00E+03

50 pen bitumen
1.00E+02
Plastomer Modified bitumen

1.00E+01 Elastomer Modified bitumen

1.00E+00
0 5 10 20 30 40 50 60 70 80
TEMPERATURE °C


EFFECTS OF POLYMERS
1E+04

Unmodified

Plastomer Modified

Elastomer Modified
MICRO STRAIN

1E+03

1E+02
1E+02 1E+03 1E+04 1E+05
CYCLES TO FAILURE


ADVANTAGES OF USING MODIFIED BITUMEN
Fig 1.0.
Severe rutting on a road built with Unmodified Bitumen, after just two years since
completion.

Fig 2.0.
Roads built with Modified Bitumen can have a lifespan of over 6 years.


UNMODIFIED BITUMEN BINDER USED FOR ROAD SURFACE

MODIFIED BITUMEN USED FOR THINNER ROAD SURFACE


TYPES OF POLYMER MODIFIED BINDERS
The Performance Graded (PG) System is a method of measuring asphalt binder performance. This system
was introduced in the USA and originally developed during the Strategic Highway Research Program (SHRP)
in the early 90’s. The Superpave™ performance grading (PG) specification classifies asphalt binders into
performance grades that change at 6°C intervals according to the service climate. Examples of Polymer
Modified Bitumen are High Impact Performance Grade Bitumen PG 76-10 and PG 82-10, both can
withstand the toughest conditions and is created with a high resistance to strong shearing forces. This type
of modified bitumen is commonly used on race tracks, railway tracks and airstrips due to increased
resistance to fuel spillage. This specialist grade of bitumen is often considered as much more expensive, but
in the long run will offer significant cost savings due to lower maintenance costs.

When Polymer Modified Bitumen (PMB) is combined with mineral aggregates it provides higher cohesion
and better adhesion compared to conventional and paving bitumen grades. PMB also offers great elastic
recovery after relief. Additional advantages and benefits of using PMB include the following: Lower
susceptibility to temperature variations, higher resistance to deformation wear and tear and Increase in
fatigue life.
In colder climatic conditions and winter months the PMB stops cracking that occurs when the road surface
contracts. On the other side of the spectrum, in extreme hot climatic conditions and summer months the
PMB stops the asphalt from softening, when road surface temperatures may exceed 65°C. Commonly used
in the Gulf, The Americas, Canada and through Africa.


HIGH IMPACT PERFORMANCE GRADE PG 76-10 SPECIFICATIONS
TEST SPECIFICATION
Flash Point Temperature (°C), T48 230 Min
Viscosity, ASTM D4402: Maximum, 3 Pa·s Test 135
Temperature (°C)

Dynamic Shear, TP5; G*/sin δ, Minimum, 1.00 kPa 76
Temperature (°C) at 10 rad/s

ROLLING THIN FILM OVEN (T240) OR THIN FILM OVEN (T179) RESIDUE
Mass loss, Maximum 1%

PRESSURE AGING VESSEL RESIDUE
P.A.V. Aging Temperature (°C) 110
Dynamic Shear, TP5; G*/sin δ, Minimum, 5000 kPa 37

PHYSICAL HARDENING REPORT
Creep Stiffness, TP1 Stiffness, Maximum, 300.0 0
MPa at 60 seconds m-value, Minimum, 0.300 at 60
seconds Test Temperature (°C)

Direct Tension, TP3 Failure Strain, Minimum, 1.0% 0
(loading rate of 1.0 mm/min)
Test Temperature (°C)


HIGH IMPACT PERFORMANCE GRADE PG 82-10 SPECIFICATIONS
TEST SPECIFICATION
Flash Point Temperature (°C), T48 230 Min
Viscosity, ASTM D4402: Maximum, 3 Pa·s Test 135
Temperature (°C)


ROLLING THIN FILM OVEN (T240) OR THIN FILM OVEN (T179) RESIDUE
Mass loss, Maximum 1%

PRESSURE AGING VESSEL RESIDUE
P.A.V. Aging Temperature (°C) 110
Dynamic Shear, TP5; G*/sin δ, Minimum, 5000 kPa 40

PHYSICAL HARDENING REPORT
Creep Stiffness, TP1 Stiffness, Maximum, 300.0 MPa 0
at 60 seconds m-value, Minimum, 0.300 at 60
seconds Test Temperature (°C)

Direct Tension, TP3 Failure Strain, Minimum, 1.0% 0
(loading rate of 1.0 mm/min)
Test Temperature (°C)


TYPES OF MODIFIED BITUMEN
1.Plastomeric Thermo Plastic Based Type-A(PMB 120, 70, 40) –
Penetration Based Polymer used PE, EVA, EBA,EMA etc.

2. Elastomeric Thermoplastic Based Type-B(PMB 120, 70, 40)–
Penetration Based Polymer used SIS, SBS, ETP etc.

3. Natural Rubber Based Type-C (NRMB 120, 70, 40) –
Penetration Based Latex or Rubber powder

4. Crumb Rubber Based Type-D (CRMB 50, 55, 60) –Softening
Point Based Crumb Rubber powder from discarded truck tires

( High Viscosity Bitumen – Class 170 & 320 deserves a mention here)


A. SPECIFICATION OF POLYMER MODIFIED BITUMEN, PMB(P)
ASTM Standards
Requirements

S.NO Characteristic PMB(P)-120 PMB(P)-70 PMB(P)-40
D5
1 Penetration at 25°C, 1/10mm, 100g, 5 sec 90-150 50-90 30-50
D 36
2 Softening Point, (R&B),°C, Min 50 55 60
-
3 Fraass Breaking Point # °C, Min -20 -16 -12
D 6084
4 Elastic Recovery at 15°C, %, Min or 50 40 30

G*/sin?, min1.0 kpa, 25 mm plate, 10rad/s at a
temp °C 52 58 72
D 92
5 Flash Point, COC, °C, Min 220 220 220
-
Separation, Difference in Softening Point, (R&B),°C,
6 Max 3 3 3
D 2170/D4402

7 Viscosity at 150°C, Poises 1-3 2-6 3-9
D 2872
8 Thin Film Oven Test & Tests on Residue - - -
D6
8a Loss in Mass, %, Max 1.0 1.0 1.0
-
Reduction in Penetration of residue at 25°C,
8b 1/10mm, 100g, 5 sec, %, Max 35 35 35
-
8c Increase in Softening Point, °C, Max 7 6 5
D 6085
8d Elastic Recovery at 25°C, %, Min or 35 30 20


B.SPECIFICATION OF POLYMER MODIFIED BITUMEN, PMB(E)
Requirement ASTM
Standards

S. NO Characteristic PMB(E)120 PMB(E)70 PMB(E)40
D5

D36
-
D6084
4 Elastic Recovery at 15°C, %, Min 70 70 70
D92
-

Separation, Difference in Softening Point,
6 (R&B),°C, Max 3 3 3
D2176
D2872

D6
-

Reduction in Penetration of residue at 25°C,
8b 100g, 5 s, %, Max 35 35 35
-

D6085
8d Elastic Recovery at 25°C, %, Min 50 50 50


C.SPECIFICATION OF NATURAL RUBBER MODIFIED BITUMEN, NRMB
Requirement ASTM
Standards

S.NO Characteristic NRMB 120 NRMB 70 NRMB40
D5

D 36
-
D 6084
D 92
-

Separation, Difference in Softening Point,
6 (R&B),°C, Max 3 3 3
D 2170/D4402

D 2872

D6
-

Reduction in Penetration of residue at 25°C, 100g,
8b 5 s, %, Max 35 35 35
-

D 6085


D. SPECIFICATION OF CRUMB RUBBER MODIFIED BITUMEN, CRMB
S.NO PROPERTIES CRMB CRMB CRMB ASTM STANDARDS
50 55 60

D5
1 Penetration at 25°C, 1/10mm, 100g, 5 sec < 70 < 60 < 50
D36
D6084
D92
-
Separation, Difference in Softening Point, (R&B),°C,
5 Max 4 4 4
D2170/D4402
D2872
7a Loss in Mass, %, Max 1.0 1.0 1.0 D6
-

Reduction in Penetration of residue at 25°C, 100g, 5s,
7b %,Max 40 40 40
-
D6085


SELECTION CRITERIA FOR GRADES OF MODIFIED BITUMEN

Lowest Mean Air Temperature °C Highest Air Mean Temperature °C

Less than 20°C 20°C to 30°C More than 30°C

More than -10°C PMB / NRMB 55 PMB / NRMB 45 PMB / NRMB 50

CRMB 50 CRMB 55 CRMB 60

-10°C or lower PMB / NRMB 55 PMB / NRMB 120 PMB / NRMB 45

CRMB 50 CRMB 50 CRMB 55


WORKING TEMPERATURE REQUIREMENT FOR MODIFIED BITUMEN

STAGE OF WORK INDICATED TEMPERATURE °C

BITUMEN AT MIXING TEMPERATURE 165 - 185

AGGREGATE AT MIXING 165 - 185

MIX AT MIXING PLANT 150 - 170

MIX AT LAYING 130 - 160

ROLLING AT LAYING SITE 115 - 145


REQUIREMENTS OF MIX PREPARED WITH MODIFIED BITUMEN
S.No Properties Requirement

Hot Cold High
Climate Climate Rainfall

1 Marshall Stability (75 12 10 12

blows) at 60oC, kN, Max - - -

2 Marshall Flow at 60oC, mm 2.5-4.0 3.5-5.0 3.0-4.5

3 Marshall Quotient, kg/mm - 250-500 -

4 Voids in Compacted Mix, % - 3.0-5.0 -
5.4% - 5.6%
4.7% - 5.2%
5 Modified Binder Content by
weight of mix-min* 4.3% - 4.7%

Retained stability after 24 hrs. in
6 water at 60oC %, min 90 95 100

7 Coating with aggregate, % 95 95 100


ENVIRONMENTAL ADVANTAGES OF USING PMB
Economic growth and changing consumption and production patterns are resulting into rapid increase in generation of
waste plastics in the world. The world’s annual consumption of plastic materials has increased from around 5 million
tonnes in the 1950s to nearly 100 million tonnes; thus, 20 times more plastic is produced today than 50 years ago. This
implies that on one hand, more resources are being used to meet the increased demand of plastic, and on the other
hand, more plastic waste is being generated. In Asia and the Pacific, as well as many other developing regions, plastic
consumption has increased much more than the world average due to rapid urbanization and
economic development.

Many of these plastics could be and are used in the manufacture of high quality modified bitumen such as:

There is a large amount of plastic waste being generated from household and agricultural waste, e.g. plastic bottles and
poly' tunnels. It is quite feasible for some of this material to be incorporated in to bituminous mixtures, both as an
"aggregate" bulking material, and as a modifier/improver of existing bituminous mixtures.

The plastics/polymers with the most obvious potential are low and high density polyethylenes, (LDPE and HDPE).
As collection and sorting of these materials becomes more established and mechanised it is possible that "mountains" of
reclaimed material will reduce cost to the point where the inclusion of these materials in bituminous mixtures will be
commercially driven.

Considerable research work, worldwide, is being performed on the inclusion of "rubber crumb" from old tyres to find an
environmental answer to disposing of used tyres, whilst improving the properties of the bituminous mixtures that contain
this rubber.


Which Is Approximately $2400 / Km of Road, in Savings


http://bitumenexporter.blogspot.com


Sadhan Ghosh is president of the International Society of Waste Management, Air and Water (ISWMAW), India
and professor of Mechanical Engineering at Jadavpur University, Kolkata. e-mail: sadhankghosh@gmail.com
Co-authors include Sannidhya Ghosh, a day scholar at the university and Asit Aich, executive engineer,
department of municipal affairs, Government of West Bengal, Kharagpur.

http://www.waste-management-world.com/index/display/article-display/6652396623/articles/waste-management-world/volume-12/issue-
5/features/rebuilding-c-d-waste-recycling-efforts-in-india.html


Prof. Vasudavan responded to this blog entry that it was a Project by a final
Year Student and it never take up after the trial run.


POLYMERS USED IN TONERS – THE KIWI WAY

http://bitumenexporter.blogspot.com/2011/03/used-toners-on-
road.html


http://bitumenexporter.blogspot.com/2010/03/recycling-of-roads-in-singapore-lta-way.html


Russia’s Gazprom and SIBUR is implementing TPE ( Thermo Plastic
Elastomers ) in Road Construction..


UCO- Used Cooking Oil with Bitumen… What about Bio-Diesel ?


PMB- Using Netherlands’ technology in India, thanks to Col. Tiwari

http://bitumenexporter.blogspot.com/2009/05/pmb-saviour-for-mumbai-
roads.html


It’s German Technology for the bleeding Bridge- Excessive Traffic moves
the bitumen


SBS for High Stress Surfaces ( Race Track )


NR –Cheaper , More resistant to Brittleness, fatigue and less rutting


CONCLUSIONS
1. The High Cost of Polymers is still a cause for concern.
2. Bitumen prices are on the rise.
3. Natural Disasters like flooding which erode roads is another factor taken into consideration.
4. CRMB AND NRMB Should be more actively specified.
5. Advance Economies are still the major users of PMB. Local Road Authorities in Developing Countries should
be better informed of the benefits of using Modified Bitumen over standard grades.
6. Increased traffic conditions will and are reducing the life span of roads. Modified bitumen is a means of
prevention, and ultimately will be the cure. It will save millions of dollars in the future and reduce the amount of
the resources used for construction.
7. Using recycled Polymers and Rubber to make Modified Bitumen helps to Save the Earth and benefit
the Environment.


THANK YOU FOR LISTENING
ANY QUESTIONS ?


Asian Bitumen Conference , Nov 2011 Singapore , Presentation by Benzene International Pte Ltd, on Modified Bitumen and the trends

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