“Winter Sealing”

Port Elizabeth2 July 2014

Kobus LouwIn conjunction with Johan Muller

Suppliers’ Perspective

OVERVIEW

• Historical Seasonal Trends

• Impact on Availability of Products

• Impact on Availability of Services

• Winter Seal Product Characteristics

• Health Safety & Environment

Binder consumption RSA

150000

200000

250000

300000

350000

400000

450000

500000

2008 2009 2010 2011 2012 2013

Ton

s

Bitumen production

Stabilisation/seals

Asphalt

SEASONALITY

• Traditional Spraying Seasons

(embargo periods)

• RSA Summer Holiday Break

• Budget / Spending Cycle

WEATHER LIMITATIONS

GRADE ROAD TEMPERATURE

Bitumen rubber 25°C

SBS/SBR (S-E1/2) 25°C

70/100 25°C

MC3000 (12% by volume paraffin) 10°C

Bitumen Emulsions (CRS and SS) 10°C

Modified Bitumen Emulsions (SC-E1/2) 10°C

Guidelines COLTO 4300-8

Comparative viscosities of various materials

Material

Viscosity (mPa.s)

25 °C 60 °C

Water 1 -

Cooking oil 50 -

Engine oil (SAE 30) 340 -

Golden syrup 12,600 -

Bitumen emulsion 150 – 1000 100 – 700

70/100 pen bitumen 240,000,000 85,000

S-E1 binder >300,000,000 > 100,000

• Excessive demand for sprayers in warmer months

• Under utilisation of equipment in colder months

• Human Capacity Utilization

• Hardware Utilization

• Maintenance problems due to over utilisationin the busy period

IMPACT OF SEASONALITY ON SUPPLIERS

Typical winter scenario

All dressed up and nowhere to go !

R5,000,000 worth of polymer

Options?

• Go to a softer grade

–70/100 → 150/200 → MC 3000

• Cut back with various cutters (Hazardous)

• Guidelines COLTO 4300-1

• Guidelines TRH3 p 52 and APPENDIX I p 209

• Use cold applied products EMULSIONS

WHAT IF TEMPERATURES ARE BELOW 25 °C ?

HOT-APPLIED BINDERS

Typical cold weather stripping

Note how little binder is attached tothe aggregate

Guidelines COLTO 4300-8

GradeROAD

TEMPERATURE

70/100 25°C

150/200 21°C

MC3000 10°C

GO TO SOFTER GRADE

• Why do we flux the binder ?

– Temporary reduction of viscosity

– Ensure wetting of aggregate

– Volatile cutters evaporate with time

– Residual binders revert to original state

– Promote early mosaic formation during compaction (re-orientation) allowing road stone embedment in the binder

CONSIDER FLUXING OPTION

BASED ON NATREF 80/100 TRH3 p52 and APPENDIX I p 209

OVERNIGHT

TEMP

ROAD

TEMP

APPROXIMATE

AIR TEMP

% CUTTER SPRAY

TEMP

> 12 > 48 > 31 0 150 – 175

9 – 12 40 – 48 26 – 31 1 – 2 132 – 149

6 – 9 32 – 40 21 – 26 3 – 4 121 – 138

3 – 6 24 – 32 16 – 21 5 – 7 115 – 135

0 – 3 16 – 24 10 – 16 7 – 9 100 – 118

CUT BACK GUIDELINE FOR 70/100 PENETRATION GRADE BITUMEN (TRH 3)

Effect of fluxant on bitumen properties on 70/100 pen bitumen

Property

% Paraffin (volume/mass) Specification

0 2 3 4 5

Penetration (0,1 mm) 70 110 145 185 251 70 – 100

Softening Point (°C) 48,8 45,1 42,9 40,1 38,6 42 - 51

Visc @ 60 °C (Pa.s) 153 115 72 51 32 > 75

Visc @ 135 °C (Pa.s)0.31 0.24 0.21 0.17 0.15 0,15 – 0,40

Minimum road surface temperature require to retain aggregate (°C)

25 23 21 19 18 -

The effect of temperature on the adhesive properties of bitumen

70/100 pen bitumen @ 27 °C

70/100 pen bitumen @ 20 °C

The effect of fluxing on the

adhesive properties of bitumen

70/100 pen bitumen (unfluxed)

20 °C

70/100 pen bitumen + 3% paraffin

20 °C

70/100 pen bitumen + 5% paraffin

20 °C

Hot-Applied Modified Binders(PMB’s and Bitumen-Rubber)

Fluxing of S-E2Viscosity vs. Temperature

0

200

400

600

800

1000

1200

140 150 160 170 180 190

Vis

cosi

ty (

mP

a.s)

Temp (°C)

70/100

0% flux

2% flux

3% flux

4% flux

5% flux

Effect of fluxant on properties of S-E2 polymer modified binder

Property

% Paraffin (volume/mass) Recommendation(TG 1)

0 2 3 4 5

Penetration (0,1 mm) 65 99 124 145 190 No spec

Softening Point (°C) 63 54 53 52 51 60 – 80

Viscosity @ 165 °C (Pa.s) 0,401 0,301 0,292 0,270 0,227 0,60 max.

Elastic Recovery @ 15 °C (%)81 83 85 83 80 > 70

Minimum road surface temperature require to retain aggregate (°C)

25 23 21 20 18 -

Comparison 70/100 vs S-E2(fluxed properties)

Property% Cutter

0 2 3 4 5

Penetration (0,1 mm)

70/100S-E2

7065

11099

145124

185145

251190

Softening Point (°C)

70/100S-E2

48,863,0

45,154,0

42,953,0

40,152,0

38,651,0

Conventional Bitumen RubberCriteria more user friendly bitumen rubber product:• Reduce temperature required to manufacture and apply

– from ~ 200°C to < 180°C

• Reduce viscosity to accommodate reduction in temperature• Maintain or improve toughness levels of the product• Maintain or improve elastic response of the product• Improve / increase the shelf-life of the product• Reduce sensitivity to time and the ever-changing physical

properties of the product• Reduce asphalt mixing or spray application temperatures• Reduce sensitivity to temperature • Remove requirement of compaction at high temperatures

Typical cutter properties

Solvent Paraffin Medium flash point solvent

High flash point solvent

Properties

Flash Point (°C), min 38 62 89

IBP (°C), min 150 180 217

Dry Point (°C), min 252 288 241

Aromatics (%m/m) 18 17 19

Cutter selection will vary depending on the suppliers’ proprietary technology

Heavy, non-flammable oils are not an option - non-volatile

PROPERTIES OF BITUMEN-RUBBER CUT BACK WITH VARYING QUANTITIES OF HIGH BOILING POINT SOLVENT

PROPERTY% HYDROCARBON CUTTER

S-R1 SPEC

R & B Softening Point (°C) 61,3 49,1 44,7 41,2 41,0 55 – 62

Resilience (%) 42 3 - - - 13 – 35

Flow @ 60 °C (mm) 20 105 127 134 147 15 – 70

Dynamic viscosity @ 190 °C (dPa.s)

34 26 19 14 9 20 - 40

Minimum recommended road surface temperature recommended to retain aggregate (°C)

25 22 - 23 20 -21 18 - 19 16 - 17 -

HEALTH SAFETY & ENVIRONMENT

• Occupational Health Safety ACT

• Injuries are costly– Person

– Families

– Equipment

– Workmen’s compensation

– Legal issues

• Loss of Productivity

• Sabita safety training

S-E 1 + 3% Fluxant (160 °C)

S-E 1 + 3% Fluxant (160 °C)

S-E 1 + 3% Fluxant (160 °C)

Cold-Applied Alternative

Bitumen emulsion

What is a Bitumen Emulsion?

COLD APPLIED ALTERNATIVE

50 microns

50

mic

ron

s

Microscopic image – bitumen emulsion x 1000

+

+ +

+

+

+

+

+

+++

+

+

+

+

+

+

Cationic Spray Grade(CRS)

Bitumen droplet

0,20 to 0,30% emulsifier

+

-

Anionic Stable Grade (SS)

+++

-++

1,0 to 1,5% emulsifier

-

-

-

- -

-

-

-

-

-

- -

- --

-

- -

-

-

-

-

--

-

- -

- -

-

-

Grades of Bitumen Emulsions

Spray Grade / Rapid Set

Mix Grade / Medium Set

Stable Grade / Slow Set

R

M

S

COLD APPLIED ALTERNATIVES

• Emulsions & modified emulsions can also be used to construct single & double seals

• Different construction approach will sometimes be required.

• Application rates may sometimes be unrealistically high

• May be necessary split emulsion sprays

COLD APPLIED ALTERNATIVES

Latex modification of bitumen

Bitumen emulsion SBR(Styrene-Butadiene-Rubber)

+

Microscopic image – bitumen emulsion + 5% latex (1000 x)

50

mic

ron

s

50 microns

Microscopic image – rubber latex (1000 x)

50

mic

ron

s

50 microns

Rubber latex

Bitumen emulsion

Particle size distribution

• Emulsions

– CRS60 {or CRS60(t)}

– CRS65 {or CRS65(t)}

– CRS 70 – could be highly viscous

• Modified emulsions

– CRS60 / 3 or 5 % (SC-E1/2)

– CRS65 / 3 or 5% (SC-E1/2)

– CRS70 / 3 or 5% (SC-E1/2)

– Fog Sprays

– CRS 60 / 65 (Cationic)

– SS 60 (Anionic)

Notify suppliers in time6-8 weeksdelivery of

raw material

COLD APPLIED ALTERNATIVES

Coalescence – different stages

Stable emulsion Flocculation Densification Coalescence

Fluxants promote development of coalescence

Coalescence – different stages

“Fluxing” of bitumen emulsions

For Cape Seals NO FLUX recommended!

SANS 4001-BT4:2014Cationic bitumen road emulsion

REQUIREMENT FOR FLUXING AGENTSSANS 4001-BT4 (Edition 1) (old SABS 548:2003)

Fluxing agents shall, when tested in accordance withMethod ASTM D86, comply with the following requirements:

(a) Initial boiling point: Not lower than 140 °C

(a) Distillate at 350 °C: Not less than 90% (v/v)

THIS PREVENTS SUPPLIERS FROM INCORPORATING “ANY” SOLVENTS

Determination of flux content (ASTM D244)

Determination of flux content (ASTM D244)

Determination of flux content (ASTM D244)

Bitumen

Determination of flux content (ASTM D244)

Flux

Typical fluxant levels used in the Western Cape

November to February

March to April to May

June to AugustSeptember to

October

2% 3% 4 – 5% 3%

Approximate residual bitumen penetration (70/100 base bitumen)

110 145 190 - 250 145

Effect of fluxing on properties of bitumen emulsions

• Improves dispersion

• Improves the “breaking” rate

• Quicker mosaic formation

• Improved viscosity

• Enhanced storage stability

Disadvantages of unfluxedbitumen emulsions

• Poorer dispersion

• Poorer storage stability

• Slower mosaic formation

• Lower viscosity

• Delay in breaking during cold weather conditions

Sedimentation of bitumen particles

STOKES LAW

V =2

9

gr

2

(D-d)

η

Where:

V = rate of settlement

g = acceleration gravity

D = density of dispersed phase

d = density of dispersion medium

r = radius of particles

η = viscosity of aqueous phase

Densities of fluxed bitumen

0.980

0.985

0.990

0.995

1.000

1.005

1.010

1.015

1.020

1.025

0 1 2 3 4 5 6 7 8 9 10

De

nsi

ty (

kg/l

)

Paraffin flux (%m/m)

Freezing/Thawing of emulsions

Thank you for your attention !