weather resistant bituminous pavementsbituminous pavements striving for sustainability through...

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ZYDEX NANOTECHNOLOGY

For Improved Resistance to :

Oxidation, Moisture, Cracking & Bleed

WEATHER RESISTANT BITUMINOUS PAVEMENTS

Striving for sustainability through prudent use of limiting natural resources and restraint in emissions is the call of the day.

This realization is at the core of all innovations at Zydex

We have taken this earth on lease from future generations. Itis our duty to return it to the future generation in liveablecondition if not better.

PREAMBLE

Light : Source of energy for life•However, prolonged exposure leads to degradation of

most of the construction materials used today.

Water : Is life•But it is also a major destroyer of materials, if in

contact for prolonged periods.

Oxygen : A life essential•But in presence of light and water, it can oxidize most

of the materials.

Sustainability Through Innovation

Understanding of the above is at the core of all our innovations

THE PARADOX OF LIFE ESSENTIALS

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Extending life means sustainability.And so is conserving limiting resources in pavement construction.

Saving Aggregates Saving Bitumen

Zydex nanotechnology enables achieving the above.

Saving Fuel

PAVEMENTS & SUSTAINABILITY

ZYDEX TECHNOLOGY ENABLES• Improved resistance to oxidation

• Reduction in water induced damage

• Improved Densities at lower compaction

temperatures

• Improved fatigue resistance (cracking)

• Improved bleed resistance

LIFE CYCLE EXTENSION – ZYDEX WAY

IMPACT OF CLIMATE ON PAVEMENTS

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Stripping Raveling & Pot Holes

MOISTURE SUSCEPTIBILITY

Air Gaps

Water Gets in

Water Evaporates& Expands

Fatigue Cracking & RuttingTemperature Difference

EXPANSION & CONTRACTION CYCLES

Undulations Larger Cracks & Weakening of sub-grade soil

FREEZE-THAW CYCLES

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LOW TEMPERATURE CRACKING

BITUMEN BLEED

OXIDATION RESISTANCETHROUGH COATING EFFICIENCY

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PRACTICAL DIFFICULTIES IN THE FIELD AND MITIGATION

Limited mixing time (20-45 sec) in the plant leads to inefficient coating, especially of fines. This is particularly relevant with higher viscosity grades and PMB / CRMB / RAP mixes (10 to 35%)

ZycoTherm (ZT or ZT-EZ) additive to bitumen decreases the surface tension of the binder by 8 to 10 dynes / cm. This leads to 30-40 % faster coating with 15-20 % less torque, leading to efficient coating in the available mixing time.

Study done at University of Texas at Austin, paper published in TRB Journal No. 2505

(ZycoTherm)

(ZycoTherm)

ZT EFFECT ON SURFACE TENSION

Bitumen Binder

Control With ZycoTherm

Entrapped AirPinhole Free Surface, Complete Saturation

With addition of ZT, due to lower surface tension the bitumen wetsthe aggregate surface better. This results in improved wetting andsaturation of micro pores on aggregate surfaces.

SLOWS AGEING PROCESS

COMPLETE COATING

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REDUCED COATING TIME OF ASPHALT MIX

ReducedCoating timeFrom 67 sec to 47 sec. with ZycoTherm(30 % reduction)

Innovationsgesellschaft Technische Universität Braunschweig mbH

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NPG @ 135 ˚C

NPG + ZT @ 135 ˚C

NPG+ZT @ 115 ˚C

NPG+ZT @ 95 ˚C

PMB @ 145 ˚C

PMB+ZT @ 145 ˚C

PMB+ZT @ 125 ˚C

PMB+ZT @ 105 ˚C

coated 50% [s]

coated 100% [s]

[Seconds]

AC 16 BS 50/70

AC 11 DS 25/55-55A


FASTER COATING AT LOWER TEMPERATURE

20 % less time is required, even at 40 0C lower mixing temperature


Power at different times During Mixing

Total Energy consumed over time

AC 16 BS 50/70

LOWER POWER CONSUMPTION

10-15 % less mixing energy required, even at 40 0C lower temperature

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FIELD OBSERVATIONS

In HMA plants, the mixes produced with ZT technology look glossier and jet black in color.

The ZT pavements have consistently remained blacker (visual Observation of the surface and the mastic compared to control sections).

This confirms that the coating has substantially improved, especially of fines and saturation of micro pores.

This will have a very positive impact on oxidation resistance.

Colorado, USA

Complete Coating

JET BLACK LOOK

FIELD OBSERVATIONS

ZT field sections have shown a remarkable reduction in cracking in the surface layers.

Saturation of micro pores and complete coating of fines leads to higher bitumen-aggregate interface area leading to better load transfer.

Reduced stress for the same mix will improve the fatigue resistance.

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It is observed that ZT mixes during production, showedlower current drawn by 10 Amp, at 20 0C lower mixingtemperature (Ref – Peab plant in Sweden).

This confirms easier mixing due to improved lubrication andworkability.

All ZT mixes are observed to be less sticky to the production, trucksand paver equipment.

ZT mixes flow easily and consistently, with improved control onsegregation. Workability with hand is also seen to be excellent. Thisis particularly relevant for achieving better lane joint densities.

EASIER MIXING & WORKABILITY – FIELD OBSERVATIONS

MOISTURE RESISTANCE

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O HO H

Soil/clay particle surface silicate structure

ZT molecule creates

molecular level

hydrophobic zone

(water repellent)

Particle surface

-OH groups make surface very hydrophilic (water loving)

Particle surface

Soil / Clay surface silicate structure after Zycotherm reaction

Newly formedSiloxane bonds

InternalSiloxane bonds

CHEMICAL BONDING OF ZYCOTHERM WITH AGGREGATES

4 - 6 nm Alkyl Siloxane surface

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ASPHALT - AGGREGATE BONDING

Surface Tension

Viscosity (temp)

Composition

ASPHALT AGGREGATE

Surface chemistry (mineral composition)

Surface texture

Porosity

Surface condition (cleanliness, moisture)

Wettability of aggregates by asphalt is an important parameter affecting asphalt aggregate bonding. Wettability depends upon composition of asphalt, viscosity and surface tension

The other important factor governing the bonding is the aggregate properties as above.

Polar Asphaltenes (5- 15%)In Non-Polar Maltenes

(85-95%) Dispersed

BITUMEN BINDER MICROSTRUCTURE

Polar - Polar Interaction

5-15 % Asphalt participates in Bonding

Non Polar – Non Polar Interaction

85-95 % Asphalt participates in Bonding

ORANGE PEEL EFFECT APPLE SKIN EFFECT

Stripped Binder

Clean Water

Aggregate

ZYCOTHERM – AGGREGATE - BINDER INTERACTION

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Basalt Aggregate (DBM) : 45% 20 mm, 10% 10 mm, 45% less than 6 mm with stone dust Asphalt Grade: AC-20 (VG-30, 60-70 penetration grade)

% C

oate

d Ag

greg

ates

BOIL TEST ASTM D3625 : EXTEND TO 6 HOURS

Basalt Aggregate (DBM) : 45% 20 mm, 10% 10 mm, 45% less than 6 mm with stone dust Asphalt Grade: AC-20 (VG-30, 60-70 pen. Grade)

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Control 2% Lime 0.5% Amine 0.1% Zycosoil24 Hours 48 Hours 120 Hours 360 Hours

0.1 % ZycoTherm

% C

oate

d Ag

greg

ates

STATIC IMMERSION AASHTO T182 TEST

EXTEND TO 360 HRS

Ave

rage

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sile

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engt

h (P

SI)

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Control 0.05% Zycosoil 0.1% Zycosoil

Unconditioned Conditioned

Georgia, USA Granites with PG 64-22 Asphalt binder

TSR 0.82 TSR 0.95 TSR 1.00

AASHTO T283 TSR TEST

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Marshall Strength- Control Marshall Strength with ZycoTherm

Unconditional Strength Conditional Strength

CSR 0.45

CSR 0.74

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MARSHALL COMPRESSIVE TEST AASHTO T165 / ASTM D1075

EXTEND TO 15 DAYS

CSR 0.45

CSR 0.74

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shal

l Sta

bili

ty (

Kg)

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Marshall Strength- Control Marshall Strength with ZycoTherm

Unconditional Strength Conditional Strength

CSR 0.45

CSR 0.81 based on dry Control

MARSHALL COMPRESSIVE TEST AASHTO T165 / ASTM

D1075 EXTEND TO 15 DAYS

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6h 24h 48h 72h

Coverage in

%

Rolling time [h]

GRANITEGRANITE 8/11 (50/70 BH)

GRANITE 8/11 (45/80‐65 H)

GRANITE 8/11 (50/70 BK)

(50/70 BH)+ZYCOTHERM

(45/80‐65 H)+ZYCOTHERM

(50/70 BK)+ZYCOTHERM

ROLLING BOTTLE PN-EN 12697-11ADHESION TEST

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LOW TEMPERATURE MIXING AND

CONSISTENT WARM COMPACTION


Environmental commitments are pushing the world to lower mixing temperatures. Lower temp of mixing and feed of wet aggregates during the paving season can lead to residual moisture which can result in poor bonding and increased moisture susceptibility.

Residual moisture acts as a catalyst for ZT to chemically react with aggregates. This ensures excellent bitumen bonding even when wet aggregates and lower mixing temperatures are encountered.


Mixes often cool down unexpectedly, due to drop in ambient temperature, high wind speeds or a sudden rain shower. This leads to inconsistent densities during paving operations.

Often, this either attracts penalty or bonus is missed due to inconsistent densities.

ZT mixes have excellent workability and show consistent compaction over extended range of temperatures, even as low as 95

0C (203 F)

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COMPACTION AT LOWER TEMPERATURE

Compaction temperatures for unmodified PG 58-22 in the range of 131-136 0C in Nova Scotia, AMEC Americas Ltd

With ZT, compaction density is achieved at a temp. lower by 25 0C

ZYCOTHERM & LOW TEMP COMPACTION

• With ZT a greater compaction can be achieved for the same and lower temperatures than the reference mix.

• Fuel savings during the mixing process and less carbon footprint benefits can be obtained as well.

Mix Type Binder Type

C / ZT

Compaction Temp OC

50 % Coating Sec

Compaction Resistance

21Nm

Void Content Vol

%

AC 16 BS 50/70 C 135 25 41.6 7.0

ZT 135 15 43.5 7.1

115 19 42.8 7.2

95 19 41.3 6.9

AC 11 DS 25/55-55 A

C 145 37 37.3 4.3

ZT 145 22 34.2 4.6

125 30 36.5 5.0

105 30 36.5 5.3

ZT - COMPACTION TEMPERATURE / RESISTANCE


With ZT the compaction resistance at lower temperature does not show any difference.

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FLEXIBILITY & FATIGUE RESISTANCE

PLASTIC DEFORMATION (RUTTING)

PLASTIC DEFORMATION (RUTTING)

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Parameters for testing

Asphalt binder : AC 20 (PEMEX, Mexico) with ZycoTherm: 0.075%; reference OBC 5.5% and with ZycoTherm OBC 5.8%; Aggregates: La Canada Quarry

Sample size:50mm H X 63 mm W X 380 mm L

Air voids : 6%

Test temperature : 20 0C

Deformation Frequency : 10 Hz for four levels - 300, 400, 500 & 600 µԑ (represents pavement deformation under normal transit condition)

Asphalt mix fatigue life failure criteria: Number of cycles in which the beam stiffness modulus decreases 50% compared to its initial value

Mexican Transportation Institute

FLEXURAL FATIGUE TEST AASHTO T321-07

Stiffness modulus evolution for beams tested with 300 µԑ


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Damage level evolution for beams tested with 300 µԑ


Stiffness modulus evolution for beams tested with 600 µԑ


Damage level evolution for beams tested with 600 µԑ


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Higher Number of Cycles means Higher Fatigue Life

FLEXURAL FATIGUE TEST

Wohler curve (fatigue law)



Beam µԑ Reference Beam Nf

ZycoTherm Beam Nf

Fatigue life Increment

1 300 3,995,009 5,480,003 37%

2 400 713,381 1,300,000 82%

3 500 224,321 380,010 69%

4 600 67,758 190,010 180%



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ZYCOTHERM & RUT RESISTANCE

• At 0,075% ZT, deformation maintained with acceptable tolerance, for similar temperatures as the reference mix, according to AMAAC specifications

• Lowering mixing temp. and compaction temp. does not affect rutting behavior.

Asphalt Type Asphalt Compaction Temp.

D0 Dynamic stability DS

Rut Depth RD

DS Spec

%0C mm passes/mm mm/min passes/mm

60-80 Pen. 5.6 142 2.08 538.5 0.078

> 500

60-80 Pen. 5.6 142 3.25 636.4 0.06660-80 Pen. + 0.1% ZT

5.6 136 1.59 1340.4 0.0313

60-80 Pen. + 0.1% ZT

5.6 140 1.79 1105.3 0.038

Comparison indicates that the Dynamic Stability of the ZT mould is more than double that of straight asphalt mould.

WHEEL TRACKING TEST (AT A LEADING JAPANESE LAB)

CONVENTIONAL ASPHALT MODIFIERS

• ORGANIC TREATMENTS• Amines, Silanes• Polyamines, Amidoamines

• INORGANIC TREATMENTS• Hydrated Lime• Portland Cement• Poly-phosphoric Acid (+ H3PO4)

• POLYMERIC AGENTS• Functionalized Butadiene• Styrene-Butadiene-Styrene (SBS)• Butyl Acrylate, Glycidyl Methacrylate (Elvaloy)• Reactive Ethylene Terpolymer

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Bitumen Parameter Outcome

Performance Grading Maintains Grading

Viscosity AASHTO T316 at 1350 C

Rotational Viscosity remains unchanged

Rutting Improves Rut Resistance (higher G*/Sinδ)

Ageing Improves retention of elasticity reflected by higher phase angle (in PAV aged asphalt binder)

Low Temperature Flexibility (BBR Test AASHTO T 313)

Similar / Higher m value at -12 0C, even though the G* shows consistently higher values at 64 0C

Stiffness Penetration number goes down

EFFECT OF ZT ON BITUMEN BINDER- PG GRADING

Addition of ZT to the binder does not affect PG grading.

Parameters 50/70 50/70 + 0.15% ZycoTherm EZ

Penetration @ 25OC [0,1 mm] 57 58

Softening Point R&B [OC] 50.4 50.6

Breaking point Fraass [OC] -16 -14

Ignition point [OC] 340 330

Source: Laboratory testing protocol TN/3229/14 IBDiM

EFFECT OF ZT ON BITUMEN BINDER – OTHER PROPERTIES

SALT RESISTANT PAVEMENTS

PG 64-22 / VG 30 / 60-70 Pen PG 76-22

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PMB Control165 C

PMB + 0.1%ZycoTherm

135 C

10 Min

1 Hr

6 Hr

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Control 135C

Control 120C

1% HydratedLime 135 C

0.5% Amine135 C

0.1%ZycoTherm

120 C

10 Min

1 Hr

6 Hr

Basalt Aggregate (DBM) : 45% 20 mm, 10% 10 mm, 45% less than 6 mm with stone dust Asphalt Grade: AC-20 (VG-30, 60-70 penetration grade)

BOIL TEST ASTM D3625 : EXTEND TO 6 HOURS

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Binder AC-10 Binder AC-20 CRMB-1 PMB-40

Control 2% Hydrated Lime 0.1% Zycosoil

2.85

2.70

3.02

2.71

3.14

3.092.95

2.78 3.183.10

3.00

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shal

l Sta

bilit

y (K

g)

3.05

Flow Values (mm)

Basalt Aggregate (DBM) : 45% 20 mm, 10% 10 mm, 45% less than 6 mm with stone dust Asphalt Grade: AC-20 (VG-30, 60-70 pen. Grade)

2% Hydrated Lime 0.1% ZycoThermControl

MARSHALL WET COMPRESSIVE STRENGTH AASHTO T165 / ASTM D1075

Asphalt Grade Asphalt Mixing Temp.

Conditioning Temp. for 1hr

% Stripping of aggregates

%0C

0C 30 min 1 hr 3 hr 6 hr

60-80 Pen. 5.5 145 145 10% 30% 40% 55%60-80 Pen. + 0.1% ZycoTherm

5.5 145 145 0% 0% 0% 0%

PMA (8% polymer) 5.5 155 145 0% 0% 10% 20%PMA (7.5% polymer) + 0.1% ZycoTherm

5.5 155 145 0% 0% 0% 0%

60-80 straight asphalt : Both, Mix with straight 60-80 asphalt and mix with ZT pass the standard test upto 30 Minutes (> 85% coating retension ASTM D3625 ).

Beyond 30 minutes of boiling, the mix with straight asphalt starts stripping rapidly. In case of ZT modified binder, no stripping is observed, even after 6 Hrs of boiling. This confirms very strong chemical bonding between aggregates and bitumen.

Even with reduced polymer (from 8 % to 7.5 %), The mix with ZT shows 0 % stripping, even after 6 Hrs of boiling.

EXTENDED BOIL TEST (AT A LEADING JAPANESE LAB)

Mix Type Binder Type

C / ZT

Compaction Temp OC

50 % Coating Sec

Compaction Resistance

21Nm

Void Content Vol

%

AC 16 BS 50/70 C 135 25 41.6 7.0

ZT 135 15 43.5 7.1

115 19 42.8 7.2

95 19 41.3 6.9

AC 11 DS 25/55-55 A

C 145 37 37.3 4.3

ZT 145 22 34.2 4.6

125 30 36.5 5.0

105 30 36.5 5.3

ZT - COMPACTION TEMPERATURE / RESISTANCE


With ZT the compaction resistance at lower temperature does not show any difference.

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ZYCOTHERM BLENDING IN BITUMEN BINDER

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weather resistant bituminous pavementsbituminous pavements striving for sustainability through...

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