WAM Foam asphalt pavements at lower temperatures WMA

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

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

Basic Concept Viscosity Pa. s Hard asphalt component PG 64 -22 100000 1000 10 Soft asphalt component 1 0. 5 r 0. 2 -60 32 0 25 50 300 210 120 75 ° F 390 480 0. 1 Temperature 3

Schematics of the typical process conditions TRADITIONAL HOT MIX ASPHALT 5% FILLER 20 OC 90% AGGREGATE DRYER MIXER 320 OF 390 OF SILO 300 -350 OF LAYING 270 -320 OF 6% ASPHALT WAM Foam ASPHALT MIX PROCESS 5% FILLER 20 OC 90% AGGREGATE DRYER MIXER 260 OF 225 OF SILO 180 -220 OF LAYING 175 -200 OF 1. 8 % SOFT 4. 2 % HARD COMPONENT 4

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

WAM Foam after two years June 2001 6

WAM Foam installation in Hot Mix Asphalt plant 2000 s a l a rigin e n i l t l pha O line nd New, 2 asphalt foam mixer 7

Batch Plant Mixing Cycle – 3. 5 ton batch Time (s) 0 5 15 25 55 35 Aggregate > 4 mm Soft Bitumen Aggregates 0 -4 mm Hard Bitumen Foam Filler Discharge - Mixing

Field trials RV 120 September 2000 WAM Foam, DG 11, PG 58 -22 (80 pen) May 2002 Reference, DG 11, PG 58 -22 (80 pen) May 2002 9

Rut development on RV 120 3. 2 mm/year Abg 11 2. 9 mm/år WAM 10

WAM Foam SMA 11, Track-paving on E 6 - June 2002 Daily traffic 22000 vehicles - 65, 2 kg/m 2 11

Adoption to Drum Mix Plant 12

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

Fume emission measurement Emission reduction Hot Mix WAM Foam TPM BSM PLEASE NOTE: Today typical Occupational Exposure Limits in Europe and US are TPM – 5 mg/m 3 In this example Hot Mix emissions are still 4 times lower than OE limit !! Source: Koenders et al, IRF 2004 TPM = Total Particulate Matter BSM = Benzene Soluble Matter 14

CO 2 emission during actual Production 15

NOx and CO emission during actual Production 16

Dust emission during actual Production 54 % reduction Production process 17

Illustrations 311 F 230 F 18

Illustrations HMA vs. WAM Foam 230 F 329 F 19

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 20

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 ? 21

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 22