“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
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 ?
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 -
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
+
-
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
• 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
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
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
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)