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

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

r Viscosity Pa.s ° F Soft asphalt component Hard asphalt component PG Basic Concept Temperature

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 O F O F 260 O F 225 O F O F O F 320 O F 5% FILLER 20 O C

5 DG 11 PG (180/220) May st WAM Foam 1999 (Norway)

6 WAM Foam after two years June 2001

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

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

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 Rut development on RV 120 WAM Abg mm/year 2.9 mm/år

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

12 Adoption to Drum Mix Plant

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

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 CO 2 emission during actual Production

16 NO x and CO emission during actual Production

17 54 % reduction Production process Dust emission during actual Production

F 230 F Illustrations

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

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 US Perspective Binder components now available in the US −Final binders: PG 70-22, PG 64-22, PG 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 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