Embed Size (px)
Citation preview
Warm Mix Asphalt in Europe 15/10/2015, Dr Ian M Lancaster, NABIn Oslo
Why warm mix?
Lower fume ~10°C lower temp – 50% less fume
Lower energy costs 30°C lower temp – 9kWh/Te less energy 30°C lower temp – 0.9litres less fuel / Te
Lower carbon emissions Less hardening of binder Better compaction Higher RAP contents Use of existing asphalt plant
0
10
20
30
40
50
60
70
NorwayItalyNetherlandsFrance
3 NABIn Oslo 2015
Legislative Drivers
Kyoto Protocol US CAIR
SOx / NOx reduction in 28 states Sustainable development principles REACH
Exposure reduction
0
10
20
30
40
50
60
70
80
90
100
0 6 12 18 24 30 36R
elat
ive
Fum
e %
Temperature reduction / °C
4 NABIn Oslo 2015
SMA 11 @130°C SMA 11 @ 150°C
Fume reduction
5 NABIn Oslo 2015
Definitions
• Cold mixes are produced with unheated aggregate and bitumen emulsion or foamed bitumen
• Half Warm Asphalt is produced between approximately 70 °C and roughly 100 °C.
• Warm Mix Asphalt is produced and mixed at temperatures roughly between 100 and 150 °C.
• Hot Mix Asphalt is produced and mixed at temperatures roughly between 120 and 190 °C The production temperatures of Hot Mix Asphalt depend on the bitumen used.
6 NABIn Oslo 2015
Technologies
Hot mix modification Foaming Additives
7 NABIn Oslo 2015
Hot mix modification
KGO process Bitumen & Coarse aggregate intoduced simultaneously Filler Fines Advantages
Lower bitumen content Mixing at 130-140°C
www.kgo.se
8 NABIn Oslo 2015
Two phase mixing
Soft bitumen followed by hard bitumen Coarse aggregate / bitumen followed by cold, wet aggregate Foaming?
9 NABIn Oslo 2015
Foam
Soft bitumen Hard bitumen
Direct Foaming
Conventional foam Origins in 1950s High pressure water injection into bitumen
Surfactant additives? Water expands ~1500 in volume Foam has a low viscosity Proven technology Bitumen origin important Capital costs
10 NABIn Oslo 2015
Foaming plant
Bitumen 180°C
Water 1-2% Compressed air
Crossover valve
11 NABIn Oslo 2015
Warm mix additives
Viscosity modifiers Organic
Fisher Tropsch waxes Fatty amides Montan waxes
Mineral Zeolites
Chemical additives No effect on viscosity or bitumen properties Reduce surface tension between aggregate & bitumen
USA 86.7MTe WMA (~25% of all asphalt) 10% using additive technology
UK showing significant appetite
12 NABIn Oslo 2015
Indirect Foaming
Moisture present in aggregates Hygroscopic fillers Zeolite additives
Alumino-silicate minerals Typically 20-25% water Na2.Al2Si3O10.2H2O Release water on a micro scale.
Do not alter asphalt grading Addition rate 0.3%
6-7h improved workability Products
Asphamin Advera
13 NABIn Oslo 2015
Organic additives
Characterised by sharp melting point Liquid above DP Can increase stiffness below DP Viscosity / temperature reduction depends on type / concentration of additive Addition rate:1.5-3% Plant addition possible Temperature reduction:20-40°C No specification for organic modified binders
020406080
100120140160
14 NABIn Oslo 2015
Organic additives
0,001
0,01
0,1
1
10
100
80 100 120 140 160 180
Visc
osity
/mPa
.s
Temperature / °C
FT-waxW-PMBPMB
0
100
200
300
400
500
600
700
800
900
0 1 2 3 4 5Vi
scos
ity /
cPs
Wax concentration %
15 NABIn Oslo 2015
Chemical Additives
No effect on bitumen properties Effect on asphalt is difficult to prove in laboratory Reduction in interfacial tension between aggregate & bitumen Improved adhesive bond Products
MWV: Evotherm Zydex: Zycotherm Arkema: Cecabase Akzo-Nobel: Rediset Iterchimica:Iterlow
Addition rates typically 0.1-1.0%
16 NABIn Oslo 2015
Warm mix asphalt 2013
0
0,5
1
1,5
2
2,5
3
3,5
4
Mill
ion
tonn
es
17
Source: EAPA “Asphalt in Figures 2013”
NABIn Oslo 2015
Warm mix asphalt production
18
0,00
0,50
1,00
1,50
2,00
2,50
3,00
3,50
4,00
DK FIN FR UK NL NO SE
Mill
ion
tonn
es
2007 2008 2009 2010 2011 2012 2013
NABIn Oslo 2015
Warm mix in the USA
0
10
20
30
40
50
60
70
80
90
2008 2009 2010 2011 2012 2013
Mill
ion
tonn
es
Direct Foam Chemical AdditiveAdditive Foam Organic Additive
19 NABIn Oslo 2015
Warm mix asphalt 2013
0
20
40
60
80
100
120
Europe USA (EAPA) USA (NAPA)
Mill
ion
Tonn
es
20
Source: EAPA “Asphalt in Figures 2013” NAPA “Annual Asphalt Pavement Industry Survey 2013”
NABIn Oslo 2015
Specifications
Asphalt standards EN 13108-1–7 Limit max temperature Min temperature Provision for additives “Should not be seen as a barrier to the introduction of WMA”
TRL PPRS666 “Specification for low temperature asphalt mixtures”
21 NABIn Oslo 2015
Case Study #1
UK Asphalt producer using RAP Desire to double RAP content in most asphalt mixes Old asphalt plant with inefficient heating
RAP content limited with conventional binders Solution : Nytherm 85
70/100 bitumen modified for warm mix applications RAP content increased to 30% Mixes produced at 110°C No difficulty with compaction
22 NABIn Oslo 2015
Case study #2
Årsunda, Sweden Re-surfacing using RAP
Solution: Foam-mix using Nyfoam 85 Mix temperature lowered to 120°C 20% less fuel 30-70% less emissions
23 NABIn Oslo 2015
Case study #3
EME binder course Restricted working
Requirement for surfacing to be laid quickly Lack of availability of good quality aggregate Solution: warm mix asphalt using Nytherm FX20
Asphalt laid at 120°C Surfacing applied with minimal delay Significant improvement in stripping resistance
24 NABIn Oslo 2015
Acknowledgements
Helene Odelius, Bitumen Technology Manager, Nynas Dennis Day, Product Support Manager, UK & Ireland, Nynas
25 NABIn Oslo 2015
For more information
26
http://www.warmmixasphalt.com/
http://www.eapa.org
https://www.fhwa.dot.gov
http://www.asphaltpavement.org/
http://www.nynas.com/
http://www.eurobitume.eu/
www.asphaltadvantages.com
NABIn Oslo 2015
Taking oil further
27 NABIn Oslo 2015
