“Winter Sealing” Port Elizabeth 2 July 2014 Kobus Louw In conjunction with Johan Muller Suppliers’ Perspective
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“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 !
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