Nanotechnology

Future of Asphalt Pavements

TYPICAL CONSTRUCTION DESIGN

WEARING COURSE

BINDER COURSE

BASE COURSE

• Chemically Reactive

• Anti-stripping Additive

• Asphalt Modifier

ZYCOSOIL FEATURES

Hydrophilic polar aggregates get converted to non-polar Hydrophobic aggregates by nano modification, at processing temperatures of HMA

THE CHEMISTRY - THEORY

ZYCOSOIL - THE CHEMICAL ACTION

O

SiO

Si

O

Si

O

Si

O

Si

O

Si

O

Si

O

O

Si

O

OO

O

Si

O

O

O

Si

O

O

O

Si

O

OO

O O

O

O

Si

O

O

O

Si

O

O

O

Si

O

O

Si Si Si Si Si SiSi

O

OO

OO O O O

O

O O

O O

O

S i

O

S i

O

S i

O

S i

O

S i

O

S i

O

S i

O

O

S i

O

O HO H

O

S i

O

O

S i

O

O H

O

S i

O

OO

O O

O

O

S i

O

O H

O

S i

O

O H

O

S i

O

O HO H

Soil / Clay / Sand / Aggregate surface silicate structure

Zycosoil creates

molecular level

hydrophobic zone

(water repellent)

Particle surface

-OH groups make surface very hydrophilic (water loving)

Particle surface

Soil / Clay / Sand / Aggregate surface silicate structure after Zycosoil reaction

Newly formedAlkyl Siloxane Nano layer 4-6 nm

InternalSiloxane bonds

Silanol Groups

O C

Zycosoil eliminates Asphalt Stripping

TSR Value (AASHTO T283) > 90 %

ANTISTRIPPING ADDITIVE

Improves

Tensile Strength

Marshall Stability

Flow Value

Rut Resistance

ASPHALT MODIFIER

Aggregate Non UniformitySingle Rock gives Good and Poor quality aggregates

Aggregates Dust Coating - A RealityCauses Reverse Emulsification of asphalt binder leading to stripping

Marginal and Quartzite Aggregates Rejected for asphalt concrete

Increased RAP content Leads to Raveling

EXISTING TECHNOLOGIES - ISSUES

WATERPROOF DEPOSITED DIRT ON AGGREGATE

1. Improve Anti-stripping Performance

2. Lower Rut Resistance

3. Lower Fatigue Resistance

4. Handling issue – Corrosive & Bad Smell

ANTISTRIPPING ADDITIVE - AMINES

1. Improves Anti-stripping and Rut Resistance

2. Reacts to form calcium silicate. Also interacts and binds carboxylated asphaltenes

3. Needs Wet Mixing, 1-2 % lime with aggregates. Requires 24 hours marination and extra fuel for drying

4. Dry mixing leads to marginal improvement

5. Its particulate nature does not allow 360 degree reactivity

ANTISTRIPPING ADDITIVE – HYDRATED LIME

Reactive anti-strip agent

Eliminates stripping (debonding)

Improves rut resistance

Improves compaction by 1 to 1.5% on the field

Glossier pavements

Does not impart any odor to the asphalt binder or asphalt mix, improved working environment

Neutral, does not cause any corrosion andskin irritation unlike lime or amines

BENEFITS

Asphalt microstructure is a continuous three dimensional association of polar “Asphaltene” (5-15%) molecules dispersed in a fluid of non-polar "Maltene” (85-95%) molecules

ASPHALT BINDER - COMPOSITION

TYPICAL AGGREGATE ZYCOSOIL REACTED AGGREGATE

Zycosoil converts Polar silanol groups to Non-polar Alkyl Siloxane

AGGREGATE SURFACE MODIFICATION

Polar Silanol Groups

Non-polar Alkyl Siloxane

Zycosoil

ASPHALT WETTING

Interface layer Clay/Stone powder/Air

Improves Wetting on aggregates

Pinhole free surface

Asphalt

Control With Zycosoil

TYPICAL INTERACTION ZYCOSOIL INTERACTION

Polar - Polar Interaction

Asphalt Binder

Aggregate

5-15 % Asphalt participates in Bonding

85-95 % Asphalt participates in Bonding

AGGREGATE-ASPHALT BINDER INTERACTION

10-20 fold

Non Polar – Non Polar Interaction

Increase

AASHTO T182 at 60°C

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)

* Less than 85% Fail, (as per specified standards)

STATIC IMMERSION TEST

BONDING –HYDROGEN / CHEMICAL

Hydrogen bond Liquid Amines

Strength for H….N and H….O is 3-9 Kcal/mole.These bonds break down at 70-90 oC

Chemical bond Zycosoil

Strength for Si-C and Si-O-Si is 90-140 Kcal/mole. These bonds break down over 300 oC

Anti-stripping properties of liquid amines is based on hydrogen bonding, while Zycosoil is based on chemical bonding

BOIL TEST ASTM D 3625, 2 hour conditioning at 135°C

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)

* Less than 75% Fail, (as per specified standards)

All control samples showed significant amount of stripped asphalt binder floating in water

ANTISTRIPPING – 6 HOUR BOILING

Untreated Treated

BOILING TEST ASTM D3625

Boil test : 6 hr, Dolomite Aggregate Keystone Quarry, Maryland, USA

Asphalt Grade – resistance to moistureAAD 1 : very poor ; AAM 1 good AAD 1 & AAM 1 sourced from FHWA, SHRP, USA

Test sample Color & Tack Coated Aggregates % (approx.)

AAD 1 + No additive

Discolored brownish mass,

no tack

10-20%complete failure

AAD 1 + 0.1% Zycosoil

Black, tacky 95%

AAM 1 + No additive

Discolored brownish mass,

no tack

20 -30%complete failure

AAM 1 + 0.1% Zycosoil

Black, tacky >95%

Chicago testing Laboratory Inc.

TENSILE STRENGTH AASHTO T283

N 70 Superpave Mix with 20 % RAP ( Illinois DOT approved mix)

Georgia, USA Granites with PG 64-22 Asphalt binder

Increased TSR values indicate significant improvement in the moisture resistance of the HMA mixtures.

TSR 0.82 TSR 0. 95 TSR 1.00

TSR VALUE

Red lines Control Hot-Mix ;Blue lines Zycosoil Modified Hot-Mix.

-20

-18

-16

-14

-12

-10

-8

-6

-4

-2

0

0 5000 10000 15000 20000 25000

Number of Passes

Ru

t D

ep

th, m

m

UDOT Limit

C ontrol

HAMBURG WHEEL TEST – RUT RESISTANCE

Moisture sensitive Dolomite AggregateKeystone Quarry under wet condition at 50 oC

Measure Control hot mix

Zycosoil modified hot mix

SIP 4600 11000

Rut Depth 10 mm Utah DOT

9300 14300

Moisture sensitive Dolomite AggregateKeystone Quarry under wet condition at 50 oC

HAMBURG WHEEL TEST – RUT RESISTANCE RESULTS

Control 4223

0.05 % Zycosoil 5692

Testing under wet condition at 60 oC instead of 50 oC normally obtained

HAMBURG WHEEL TEST – RUT RESISTANCE SIP VALUE

COMPACTION

Air Voids of Mix Design Asphalt Concrete (4.9 % Binder, Maryland Aggregates)

MARSHALL STABILITY & FLOW VALUE ASTM D1075 : AASHTO T165 at 60 oC, 24 hrsBasalt aggregate: 45% 20mm, 10% 10mm, 45%

less than 6mm with stone dust

Flo

w

Val

ue

2.7

2.71

3.052.85

3.13.023

2.95 3.14

3.09

3.182.78

Zycosoil improves Marshall Stability significantly while maintaining the flow value. Maximum gain happens in the CRMB mix

MARSHALL STABILITY STRENGTH ASTM D1075 : AASHTO T165 at 60 oC, 24 hrs

Basalt aggregate: 33% 20mm, 24% 10mm, 41% less than 6mm with stone dust

% Binder Content with 0.1 % Zycosoil

Flo

w

Val

ue

Control

3 3.8 3.35 3.2 2.61

MARSHALL STABILITY & FLOW

VALUE ASTM D1559

Field Results, California, USA

0.1 % Zycosoil added to 5.85 % Asphalt Grade PG 64-22

High stability and high Flow Value indicates more area under the stress- strain curve. Improved Fatigue resistance

Sample Specific Gravity

Density Stability Flow Air Voids

pcf lbs 0.01inch

%

1 2.455 152.8 10246 15 2.4

2 2.442 152 9407 16 2.9

3 2.443 152 9741 15 2.9

Avg 2.447 152.3 9798 15 2.7

HVEEM STABILOMETER TEST CT 304, 356

Briquette Number

Height -Inches

Relative stability

1 2.5 42

2 2.51 41

3 2.51 42

Avg 2.51 42

Specified Standard for California •Rural Roads 32 - 34•City Roads 34 -36 •Highways 37 – 38

Field Results, California, USA

0.1 % Zycosoil added to 5.85 % Asphalt Grade PG 64-22

Sample Viscosity Pa S

Control 0.470

Zycosoil (0.05 %) 0.468

Zycosoil (0.1 %) 0.458

AASHTO T 316 AT 135 OC, PG 64-22 BINDER

Lower viscosity of the Zycosoil containing asphalt binders is good for mixing and wetting and also results in relatively lower mix temperatures

ROTATIONAL VISCOSITY TEST

AASHTO T 315 AT 64 OC, PG 64-22 BINDER

Sample G* kPa Phase Angle

G*/Sin δkPa

Specification

Control 1.44 86.4 1.44

> 1.00 kPaZycosoil (0.05 %)

1.56 86.4 1.57

Zycosoil (0.1 %)

1.55 86.4 1.55

Addition of Zycosoil improved complex modulus G*/sinδ (binder stiffness) with the same visco- elastic response (phase angle).

DYNAMIC SHEAR RHEOMETER TEST

Sample G* kPa

Phase Angle

G*/sin δkPa

Specification

Control 3.44 82.7 3.47

> 2.20 kPaZycosoil (0.05 %)

3.75 82.8 3.78

Zycosoil (0.1 %)

4.00 82.7 4.02

Increase in G*/sinδ indicates improved rut resistance of the asphalt mix, unlike Amines, which reduce the rut resistance

DYNAMIC SHEAR RHEOMETER AASHTO T 315 AT 64 0C, PG 64-22 BINDER

ROLLING THIN FILM OVEN TEST (RTFOT) AASHTO T 240

DYNAMIC SHEAR RHEOMETER AASHTO T 315 AT 25 OC, PG 64-22 BINDER

Sample G* kPa Phase Angle

G*sin δkPa

Specification

Control 6373 43.3 4368

< 5000 kPaZycosoil (0.05 %)

6001 44.1 4173

Zycosoil (0.10%)

6628 44.8 4668

PAV aged Zycosoil asphalt binders residue showed higher phase angle, which means increased elasticity compared to control

PRESSURE AGING VESSEL (PAV) TEST AASHTO R 28

AASHTO T 313 AT -12 OC, PG 64-22 BINDER

Sample Stiffness MPa

Specification

m -value

Specification

Control 201

< 300

0.312

> 0.300 mPa

Zycosoil (0.05 %)

202 0.317

Zycosoil (0.1 %)

186 0.314

Stiffness and m value are statistically similar or better at -12 oC, even though the G* shows consistently higher values at 64 oC

This is important for asphalt pavements in extreme climate regions.

BENDING BEAM RHEOMETER (BBR) TEST

TERMINAL ADDITION

Test Sample 5.1% asphalt binder on weight of mix

Stability in kg Ratio %

Flow value in mm

Dry Wet Dry Wet

Unaged binder Control 2265 2015 89.0 2.7 2.9

Unaged binder – Zycosoil (0.1%)

2485 2320 93.4 2.8 3.1

Aged binder 15 days – Control

2235 2011 90.0 2.8 3.2

Aged binder 15 days – Zycosoil (0.1%)

2652 2445 92.2 2.77 3.14

MARSHALL STABILITY STRENGTH ASTM D1075; AASHTO T165 at 60 oC, 24 hrs

Zycosoil was added in asphalt binder and aged at 150 0C for 15 days

Efficacy of Zycosoil does not diminish when the hot binder modified with it, is stored for a long period of 15 days

POROUS PAVEMENT -OGFC(OPEN GRADED FRICTION

COURSE)

Severe hydraulic scouring by vehicle tire movement, pushes the water through the porous pavements at high pressure and speed leading to stripping failures.

Zycosoil modified asphalt binder will improve strength and stripping resistance which in turn will extend the pavement life.

WARM MIX ASPHALT

Water induced foaming technique for WMA leads to moisture susceptibility and poor compaction. This is a major constraint in its adoption.

Residual moisture in aggregates due to lower temperatures, results in sub-optimal bonding of aggregate to asphalt

Residual moisture Promotes reactivity of Zycosoil resulting in improved bonding reaction and reduced moisture susceptibility.

Improved workability leads to similar Mat densities and compaction at lower temperatures.

SLURRY SEAL / MICRO-SURFACING

Zycosoil is the only water and asphalt soluble reactive anti-stripping agent.

Reacts with aggregates at room temperature in aqueous media after drying

Ideal for improving moisture resistance in micro-surfacing / slurry seal formulations

SLURRY SEAL / MICRO-SURFACING

ISSUES

High quality aggregates…..A Must

Moisture susceptibility

Poor wetting

Anti-stripping additives not available

SLURRY SEAL / MICRO-SURFACING

ZYCOSOIL BENEFITS

Marginal aggregates can be used Richer appearance of surface due to improved wetting

Reduced weight loss per unit area as tested by WTAT

SLURRY SEAL / MICRO-SURFACING

70-gm of Zycosoil per ton of Slurry Seal / Micro-surfacing mix design to be added in the water phase.

For marginal / poor aggregates use up to 140-gm per ton of mix design.

Ensure Zycosoil water solution is sprayed first on aggregates before additives or asphalt emulsion

DOSAGE

SLURRY SEAL / MICRO-SURFACING

BOIL TEST, ASTM D3625

Mixes prepared with & without Zycosoil and dried and conditioned outside in the sun for one day.

Sr. No.

Basalt Aggregates per ton of mix

% Coated Aggregate

1 hr 3 hr

1 Control 40% <5 %

2 70 gm Zycosoil 98% 90%

3 140 gm Zycosoil 98% 96%

Medium setting cationic emulsion

CONVENTIONAL TACK COAT

Cationic Asphalt Emulsions are primarily used to improve bonding of base asphalt layer

Dust, stone powder, broken aggregates on base asphalt layer are water loving and act as a primary cause of de-bonding failures

Mechanical Vibrations during milling operation leads to formation of micro cracks in base asphalt layer. Wetting and penetration of cationic emulsion is poor

ZYCOSOIL TACK

COAT Zycosoil water when used for dilution of cationic asphalt emulsion

Waterproofs dust, stone powder, broken aggregates on base asphalt layer …. Better bonding.

Better wetting and penetration of cationic emulsion in micro cracks

Keeps the spray nozzles clean and maintain uniform application

Diluents Water Zycosoil Water (1:100)

Cationic Asphalt Emulsion : Water Ratio

1 : 1 1 : 2

WATERPROOFED TACK COAT

Start circulation pump and add Zycosoil in water. Allow 5 – 10 minutes for mixing followed with addition of Cationic Emulsion before application.

Spray 400 – 700 gm/ m2 of diluted cationic asphalt emulsion

THANK YOU