1. WAM Foam: asphalt pavements at lower temperatures WMA TWG, 12 December 2007, Hunt Valley - MD

2. 2 WAM Foam Basic Concept & History Field Experience Emission Reduction US Perspective

3. 3 100000 10000 1000 100 10 1 0.5 r 0.2 0.1 Viscosity Pa.s -60-60 32 120 210 300 390480 ° F Soft asphalt component Hard asphalt component PG 64-22 Basic Concept 0 50 75 25 Temperature

4. 4 DRYER MIXER SILO LAYING DRYER MIXER SILO LAYING TRADITIONAL HOT MIX ASPHALT WAM Foam ASPHALT MIX PROCESS 6% ASPHALT 5% FILLER 20 O C 90% AGGREGATE 1.8 % SOFT 4.2 % HARD COMPONENT 90% AGGREGATE Schematics of the typical process conditions 390 O F 300-350 O F 270-320 O F 260 O F 225 O F 180-220 O F 175-200 O F 320 O F 5% FILLER 20 O C

5. 5 DG 11 PG 52-28 (180/220) May 1999 1 st WAM Foam 1999 (Norway)

6. 6 WAM Foam after two years June 2001

7. 7 foam mixer 2000 Original asphalt line New, 2 nd asphalt line WAM Foam installation in Hot Mix Asphalt plant

8. Aggregate > 4 mm Soft Bitumen Aggregates 0-4 mm Hard Bitumen Foam Filler Discharge 0 25 35 55Time (s) 5 - Mixing 15 Mixing Batch Plant Mixing Cycle – 3.5 ton batch

9. 9 WAM Foam, DG 11, PG58-22 (80 pen) May 2002 Reference, DG 11, PG58-22 (80 pen) May 2002 Field trials RV 120 September 2000

10. 10 Rut development on RV 120 WAM Abg 11 3.2 mm/year 2.9 mm/år

11. 11 WAM Foam SMA 11, Track-paving on E6 - June 2002 Daily traffic 22000 vehicles - 65,2 kg/m 2

12. 12 Adoption to Drum Mix Plant

13. 13 Emission measurements Source: Koenders et al, IRF 2004 Asphalt Fume Emission monitoring

14. 14 Emission reduction Hot Mix WAM Foam TPM = Total Particulate Matter BSM = Benzene Soluble Matter TPMBSM PLEASE NOTE: Today typical Occupational Exposure Limits in Europe and US are TPM – 5 mg/m3 In this example Hot Mix emissions are still 4 times lower than OE limit !! Fume emission measurement Source: Koenders et al, IRF 2004

15. 15 CO 2 emission during actual Production

16. 16 NO x and CO emission during actual Production

17. 17 54 % reduction Production process Dust emission during actual Production

18. 18 311 F 230 F Illustrations

19. 19 Illustrations HMA WAM Foam 329 F 230 F vs.

20. 20 What has been we achieved with WAM Foam? 30 % reduction in energy consumption, lower production costs 30 % reduction in CO 2 -emissions, a gain for the environment! 50 – 60 % reduction in dust emission, again a gain for the environment Fume from WAM Foam is below detection limits, Health & Safety! Reduced temperature => reduced oxidation/ageing of binder WAM Foam satisfies all Hot Mix Asphalt specifications according to Handbook 018 (Norwegian Standard) Production Capacity maintained

21. 21 US Perspective Binder components now available in the US −Final binders: PG 70-22, PG 64-22, PG 58-28 Laboratory −2007 mixing trials at Turner Fairbank / FHWA −2007 evaluation at NCAT Included in study Industry tour 2007 Further US field verification 2008 −Mid West −Expand to modified grades ?

22. 22 US Perspective Positives (when compared to other WMA): No Additives, no expensive snake oils – “just add water” Pre-coats Coarse Aggregate −Absorptive Aggregates Challenges: Paradigm Shift −Asphalt Plant Binder Blending −PG Binder Grading system −Performance Acceptance Projects Mix Design-Lab Foaming device Asphalt Plant Modifications