Warm Mix Asphalt in Europe. 20/10/2015, Dr Ian M Lancaster, NABIn Oslo

Transcription

1 Warm Mix Asphalt in Europe 20/10/2015, Dr Ian M Lancaster, NABIn Oslo

2 2 NABIn Oslo 2015

3 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 Norway Italy Netherlands France 3 NABIn Oslo 2015

4 Legislative Drivers Kyoto Protocol US CAIR SO x / NO x reduction in 28 states Sustainable development principles REACH Exposure reduction Relative Fume % Temperature reduction / C 4 NABIn Oslo 2015

5 Fume reduction SMA C SMA 150 C 5 NABIn Oslo 2015

6 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

7 Technologies Hot mix modification Foaming Additives 7 NABIn Oslo 2015

8 Hot mix modification KGO process Bitumen & coarse aggregate intoduced simultaneously Filler Fines Advantages Lower bitumen content Mixing at C 8 NABIn Oslo 2015

9 Two phase mixing Soft bitumen followed by hard bitumen Coarse aggregate / bitumen followed by cold, wet aggregate Foaming? Soft bitumen Hard bitumen Foam 9 NABIn Oslo 2015

10 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

11 Foaming plant Crossover valve Bitumen 180 C Water 1-2% Compressed air 11 NABIn Oslo 2015

12 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

13 Indirect Foaming Moisture present in aggregates Hygroscopic fillers Zeolite additives Alumino-silicate minerals Typically 20-25% water Na 2.Al 2 Si 3 O 10.2H 2 O 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

14 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 NABIn Oslo 2015

15 Chemical Additives No effect on bitumen properties Effect on asphalt is very 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 % 15 NABIn Oslo 2015

16 Organic additives FT-wax W-PMB PMB Viscosity /mpa.s 1 0,1 Viscosity / cps ,01 0, Temperature / C Wax concentration % 16 NABIn Oslo 2015

17 Warm mix asphalt ,5 3 Million tonnes 2,5 2 1,5 1 0,5 0 Source: EAPA Asphalt in Figures NABIn Oslo 2015

18 Warm mix asphalt production 4,00 3,50 3,00 Million tonnes 2,50 2,00 1,50 1,00 0,50 0,00 DK FIN FR UK NL NO SE NABIn Oslo 2015

19 Warm mix in the USA Million tonnes Direct Foam Additive Foam Chemical Additive Organic Additive 19 NABIn Oslo 2015

20 Warm mix asphalt Million Tonnes Europe USA (EAPA) USA (NAPA) Source: EAPA Asphalt in Figures 2013 NAPA Annual Asphalt Pavement Industry Survey NABIn Oslo 2015

21 Specifications Asphalt standards EN 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 Test methods for warm mix asphalt? 21 NABIn Oslo 2015

22 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 Normal RAP content 5-10% Increased to 10-20% Mixes produced at 110 C No difficulty with compaction 22 NABIn Oslo 2015

23 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

24 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

25 Acknowledgements Helene Odelius, Bitumen Technology Manager, Nynas Dennis Day, Product Support Manager, UK & Ireland, Nynas 25 NABIn Oslo 2015

26 For more information NABIn Oslo 2015

27 27 NABIn Oslo 2015 Taking oil further