VALUE ADDED BITUMEN

Mankind is driven forward by dim apprehensions of things too obscure for it’s existing language.

Zen and the Art of Motorcycle

Maintenance,

Robert M. Pirsig

What is Bitumen?

A viscous liquid or a solid, consisting essentially of Hydrocarbons and their derivatives, which is soluble in Trichloroethylene and is substantially non-volatile and softens gradually when heated. It is Black or Brown in colour and posses water proofing & adhesive properties. It is obtained by refining processes from Crude Petroleum.

B I T U M E N

A VISCO - ELASTIC MATERIAL

Engineering Properties of Bitumen

Bitumen is a visco-elastic material & it’s deformation under stress is a function of both temperature & loading time At higher temperature &/or longer loading time

Behave as viscous liquids At low temperature &/or short loading time

Behave as elastic solids

The intermediate range of temperatures, more typical of the conditions in service, result in visco-elastic behaviour.

The Stiffness Concept

In solids :

E =

where E = Elastic modulus

Stress

Strain

The Stiffness Concept

St,T =

t,T

Where St,T = Stiffness modulus at

specific time t & Temp. T.

Stress

t,T = Strain at specific

time t & temp. T.

COMPOSITION

B I T U M E NB I T U M E N

Elemental Analysis

Carbon 82 - 88 %

Hydrogen 8 - 11 %

Sulphur 0 - 6 %

Oxygen 0 - 1.5 %

Nitrogen 0 - 1 %

Chemical Composition

Bitumen

Asphaltenes (5 to 25 % wt.)

MaltenesSaturates (5 to 20 % wt.)

Aromatics (40 to 65 % wt.)

Resins (10 to 20 % wt.)

Elemental Analysis

• Elemental composition depends on • origin of crude • processes used in refinery

• Elemental composition • Extremely complex with the number of molecules

with different chemical structures being very large • Not feasible to attempt a complete analysis• Elemental composition provides little information

of the types of molecular structure

Properties Properties

of

BITUMEN

of

BITUMEN

Properties of Bitumen

Characteristics 80/100 60/70 30/40

Specific gravity at 27OC 0.99 0.99 0.99

Softening Point OC 35 to 50 40 to 55 50 to 65

Penetration at 25OC, 100gm, 80 to 100 60 to 70 30 to 405 secs., 1/10 mm

Ductility at 27OC, in cm min. 75 75 50

SIGNIFICANCE OF TESTS

Penetration Test Indicates consistence

Softening Point Indicates melting temperature

Loss on heating / thin film oven test Hardening on road

Ductility Test Affinity for aggregates

Solubility in Trichloroethelene Indicates purity of Bitumen

Penetration

Travel in dmm of a specified needle under 100 g wt. for 5 secs into Bitumen at 25OC Denotes consistency

Softening Point

3.5 g steel ball placed on Bitumen sample in Brass ring Bath temp. raised at 5OC per minute

DUCTILITY

Indicates the extent to which a sample can be stretched before breaking.

Length in cm. at breaking point is ductility

FLASH POINT

Used to measure temperature to which a sample bitumen may be safely heated

The flash point is the temperature reached when the vapour causes an instantaneous flash

Value Added Bitumen

Cutback Bitumen Emulsions Modified Bitumen Modified Bitumen Emulsions Multigrade Bitumen

CUTBACK CUTBACK

BITUMENBITUMEN

CUTBACK BITUMEN

Manufactured by blending solvents like Kerosene with Bitumen

Free flowing liquid at ambient temperature Used for tack coat and prime coat

applications.

Types of Cutbacks

Rapid Curing (RC 70, 250, 800, 3000) For aggregate passing 2.36 mm sieve

Medium Curing (MC 70, 250, 800, 3000) For less than 20% aggregate passing 2.36 sieve

Slow Curing (SC 70, 250, 800, 3000) For more than 20% aggregate passing 2.36 sieve

BITUMEN BITUMEN

EMULSIONSEMULSIONS

Bitumen Emulsion

Chocolate brown free flowing liquid at ambient temperature

Stable dispersion of fine globules of bitumen in continuous water phase

Dispersion is obtained by processing bitumen and water under controlled conditions through a colloidal mill with selected additives.

Types of Bitumen Emulsion

Cationic Bitumen Emulsion & Anionic Bitumen Emulsion.

Anionic not used for road work as aggregates are generally siliceous.

Cationic Bitumen Emulsions used in roadwork worldwide.

Emulsion Ingredients

Bitumen (80/100) Emulsifier Chemicals / additives Water

Emulsification

Bitumen milled into fine particles & held in molecular spaces of water

Use of correct emulsifier / chemicals facilitate proper emulsification

Breaking

Electrostatic attraction causes breaking of emulsion

Bitumen +ve charge Aggregate -ve charge Result : excellent bonding / antistripping

between bitumen & aggregate

Types of Cationic Emulsions

Slow Setting

Medium Setting

Rapid Setting

MODIFIED BITUMEN

Binder of the futureBinder of the future

Why Modified Bitumen?

Demands on Road increasing every year Increasing Number of Vehicles Increasing Axle Load Desire to maintain higher serviceability level

Higher fatigue resistance Higher resistance to weathering Better adhesion Higher stiffness modulus Lesser cracking, ravelling, deformation & creep failure Reduce number of overlays

Reduction in vehicle operation cost

Types of Modifiers

Polymers RubbersPlastics

ThermoplasticLDPE, EVA, EBA

ThermosetEpoxy Resins

Synthetic ElastomersSBS, SBR etc.

Crumb Rubber

Chemically Treated

Natural Rubber(Latex)

Plain

Properties of Modifier

Be compatible with Bitumen Blend with Bitumen properly & thoroughly Improve temperature resistance of Bitumen Resist degradation of Bituminous mix Be capable of being processed by conventional

mixing plants and laying machinery Produce coating viscosity at application temp. Maintain premium properties during

storage,application and in service. Be cost-effective considering life cycle cost

MODIFIED BITUMEN MODIFIED BITUMEN

EMULSIONSEMULSIONS

MODIFIED BITUMEN EMULSIONS

It is an Emulsion of Modified Bitumen Has the advantages of Modified Bitumen &

Emulsions both Natural Rubber Modified Bitumen

Emulsions Polymer Modified Bitumen Emulsions

MULTIGRADE MULTIGRADE

BITUMENSBITUMENS

MULTIGRADE BITUMEN

Resists cracking at low temperature Resists deformation at high temperature Reduced rutting at heavy traffic loads Reduced cracking due to high traffic

frequencies Resists Aging Optimize adhesion Optimize emulsability

Thank YouThank You