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4
“Winter Sealing”
Pretoria10 April 2014
Johan MullerIn conjunction with Kobus Louw
OVERVIEW
• Supply & Demand
• Impact on Availability of Products
• Impact on Availability of Services
• Seasonal Indexes
• Winter Seal Product Characteristics
• Health Safety & Environment
HISTORICAL SUPPLY (PROJECTED)
THEORETICAL SUPPLY & DEMAND
SUPPLY & DEMAND
IMPACT ON AVAILABILITY OF PRODUCT
• Bitumen supply shortfalls
• Imported Bitumen
– Price
– Logistics
• Secondary product availability
• Anything is possible but not always practical
• Careful planning required.
SEASONALITY
• Why is there a seasonality?
• Seasons (Autumn & Winter & Spring)
• RSA Summer Holiday Break
• Budget / Spending Cycle
• Embargo Periods
• Lack of planning (common sense)
• Knowledge base
WEATHER LIMITATIONSGRADE TEMPERATURE
ROAD OVERNIGHT
Bitumen rubber 25°C ? °C
Bitumen rubber (Winter Grade) As spec by project spec
SBS SBR (ex 80/100) 25°C ? °C
80/100 25°C ? °C
SBS or SBR (ex 150/200) 21°C ? °C
SBS or SBR (Winter Grade) As spec by project spec
150/200 21°C ? °C
MC3000 10°C ? °C
MC800 10°C ? °C
Bitumen Emulsions 10°C ? °C
Modified Bitumen Emulsion 10°C ? °C
Guidelines COLTO 4300-8
• Supply & Demand for Sprayers
• Cost of fleet
• Staff complement employment
• Hardware Utilization
• Human Capacity Utilization
• Maintenance
• COF’s (Roadworthiness)
• Calibration & Certification (Koedoespoort)
IMPACT ON AVAILABILITY OF SERVICES
• Supply & Demand for Sprayers
• Cost of fleet
• Staff complement employment
• Hardware Utilization
• Human Capacity Utilization
• Maintenance
• COF’s
IMPACT ON AVAILABILITY OF SERVICES
Options?
• Go to a softer grade
– 80/100 → 150/200 → MC3000
• Cut back with various cutters (Permitted?)
• Guidelines COLTO 4300-1
• Guidelines TRH3 p52 and APPENDIX I p 209
• Use cold applied products EMULSIONS
WHAT IF TEMPERATURES ARE BELOW?
Hot-applied binders(penetration grade bitumen)
Typical cold weather stripping
Note how little binder is attached tothe aggregate
Guidelines COLTO 4300-8
Grade ROAD
TEMPERATURE
AIR
TEMPERATURE
OVERNIGHT
TEMPERATURE
80/100 25°C ? ?
150/200 21°C ? ?
MC3000 10°C ? ?
MC800 10°C ? ?
GO TO SOFTER GRADE
• Why do we cut back?
– Temporary reduction of viscosity
– Ensure wetting
– Volatile cutters evaporate
– Residual binders revert to original seal grades
– Promote early mosaic formation during compaction (re-orientation) allowing road stone embedment
CONSIDER CUT BACK 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 2 – 1 132 – 149
6 – 9 32 – 40 21 – 26 4 – 3 121 – 138
3 – 6 24 – 32 16 – 21 7 – 5 115 – 135
0 – 3 16 – 24 10 – 16 9 – 7 100 – 118
< 0 NO SEAL WORK RECOMMENDED
Engineers’ call
CUT BACK GUIDELINE FOR BITUMEN
Determination of the quantity of cutter (fluxant) required
Effect of fluxant on bitumen properties on 70/100 pen bitumen
Property
% Paraffin (volume/mass) Specification
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 -
70/100 pen bitumen @ 20 °C
70/100 pen bitumen @ 27 °C
The effect of fluxing on the
adhesion 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 & 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) 401 331 292 270 227 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
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
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
25 22 - 23 20 -21 18 - 19 16 - 17 -
HEALTH SAFETY & ENVIRONMENT
• Occupational Health Safety ACT
• Injuries are costly
– Person
– Families
– Companies
– Workmen’s compensation
• 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)
Picture of exploded sprayer
Guidelines in COLTO 4300-8
Grade ROAD
TEMP
AIR
TEMP
OVERNIGHT
TEMP
80/100 25 ? ?
150/200 21 ? ?
MC3000 10 ? ?
MC800 10 ? ?
Bitumen Emulsions 10 ? ?
Modified Bitumen Emulsion 10 ? ?
COLD APPLIED ALTERNATIVES
What is a Bitumen Emulsion?
COLD APPLIED ALTERNATIVES
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 be required.
i.e.:
Single seal 1st spray a tack application
stone application
2nd spray a penetration application
Double seal stone application
3rd spray a penetration application
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
• Emulsions
– CRS60 {or CRS60(t)}
– CRS65 {or CRS65(t)}
– CRS 70 (made to order)
• Modified emulsions
– CRS60 / 3,5 (made to order)
– CRS65 / 3,5 (made to order)
– CRS 70 / 3,5 (made to order)
• 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!
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 TO INCORPORATE “ANY” SOLVENTS
Determination of flux content (ASTM D244)
Determination of flux content (ASTM D244)
Determination of flux content (ASTM D244)
Determination of flux content (ASTM D244)
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%
Effect of fluxing on bitumen emulsions
• Improves dispersion
• Improves the “breaking” rate
• Quicker mosaic formation
• Improved viscosity
• Enhanced storage stability
Disadvantages of unfluxedbitumens
• Poorer dispersion
• Poorer storage stability
• Slower mosaic formation
• Lower viscosity
• Delay in breaking during cold weather conditions
Sedimentation of bitumen particles
STOKES FORMULA
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
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