John A. D’Angelo US Federal Highway Administration CUPGA 2008 Saskatoon, Saskatchewan

2 How Many WMA Technologies are Available in the U.S.?

3 How Many WMA Technologies are Available in the U.S.?

Currently 12 Technologies Actively Marketed and Available in the U.S.

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Warm Mix Trials and Demonstrations Trial completed

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There is a tremendous growth in interest in Warm Mix in the US

WHY?

Fuel costs are up.

Bitumen cost have spiked.

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Change in Producer Prices for Construction Segments

Source: BLS (CPI, PPI)

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Change in Producer Price Indexes (PPI) for Highway Inputs

Source: BLS (CPI, PPI)

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Change in Producer Price Indexes (PPI) for Asphalt

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Economic Drivers for Using RAP

Growth in recycling occurs when it is economical to do so. Warm Mix Technology can improve RAP workability.

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Fractionated RAP

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A review of some projects and what we have learned

Hall Street St. Louis I70 Colorado Entrance to Yellowstone

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Hall Street, St. Louis, MO

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St. Louis Paving Schedule

Control (12.5mm PG 70-22) – 5/17/06 Sasobit – 5/18/06 Sasobit – 5/19/06 Evotherm – 5/22/06 Evotherm – 5/23/06 Aspha-Min – 5/25/06

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Interstate 70, Dillon, CO

70 miles West of Denver, CO Elevation 8,800 – 11,100 Feet Dillon

Interstate 70, Dillon, CO

Mix Type Control 7-24-07 Advera WMA Control Field Property Low Air Temp. (°F) Delivery Temp. (°F) At Screed Temp. (°F) Mat Density (% Rice)

54 * * 93.8

54 260 243 93.3

50 * *

95.7

(single data point)

* Minimum delivery temp for control HMA was 280 ° F

7-26-07 Sasobit

50 235 230 93.2

Control 8-13-07 Evotherm

36 * * 93.7

36 243 235 94.7

17 Chart is Courtesy of CODOT

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Construction Highlights

Mix Type Control 7-24-07 Advera WMA Control 7-26-07 Sasobit Control Property

Results are from the CDOT QA lab – QC results were comparable FHWA’s mix flow number, dynamic modulus and binder test data are pending.

8-13-07 Evotherm AC (%)

6.23

6.38

6.41

6.32

6.04

6.38

Voids (%) VMA (%)

3.1

16.5

1.8

15.7

3.0

16.5

2.4

15.9

3.6

16.3

2.2

15.8

Mat Density (% Rice)

~94 ~94 ~94 ~94 ~94 ~94

TSR (%)

100 83

*97

111 94 80

Stability

36 34 35 36 35 34

Hamburg (mm rut)

9.46

9.79

17.31

10.49

10.10

14.86

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Average of other control mix tested on the job. Regardless of

Hamburg

Rut Depth , Moisture damage more prevalent in the WMA samples than the control samples – see following pictures

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Conclusions

WMA decreased voids in lab compaction WMA field compaction comparable at lower temps Hamburg moisture damage visibly more in WMA Early WMA performance equal to HMA on the job No rutting, no early distresses Confident that WMA facilitates cold temp. placement Will use more WMA in this corridor if performance is comparable to HMA

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East Entrance, Yellowstone, WY

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Mixture Locations

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Yellowstone Hamburg

Control - 3.82 mm and 4.00 mm Advera - 3.80 mm and 3.25 mm Sasobit - 3.28 mm and 2.60 mm *All the testing was performed at 40 °C wet and reported at 20,000 passes.

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FLH-What Have We Learned

Field density achieved in all cases Saved ≈ 20% in fuel at the plant Temperature at plant hard to regulate Mix handled similarly Workers noted no handling difficulties No smoke Additives don’t seem to affect mix design Sasobit stiffens binder

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Binder Characterization Objective

Evaluate the effects of three Warm Mix process namely Sasobit, Aspha-Min and Evotherm on M320-Table 2 Performance Grade To Compare the Performance Grades of Warm Mix processes with the base asphalt used in preparing warm mix asphalts

Hall Street, St. Louis, MO

M320 Continuous

Performance Grade

M320, Table 2

Performance Grade

Additive Rate

, by wt of binder

Base 70.9 – 24.8

70 - 22 w/ Sasobit 76.5 – 22.8

w/ Aspha-Min 72.4 – 24.6

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Evotherm (recovered per ASTM D 6934) 66.6 – 26.7

76 - 22 70 - 22 64 - 22

1.5% 5.26%

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Findings

Sasobit – increase of one high temp. PG grade Aspha-Min - no effect on PG grade Evotherm recovered at BASF, no effect on the PG grade recovered from the stored emulsion, reduced by one high temp. PG grade

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Cost Example

Fuel usage 2.12 gallons/ton of mix -- Control 1.62 gallons/ton of mix -- Advera 1.80 gallons/ton of mix -- Sasobit • 20 to 25 % fuel savings ≈ $1/ton of mix • Cost for Advera ≈ $3.30/ton of mix • Cost for Sasobit ≈ $2.30/ton of mix • Cost occurred in August 2007

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WMA Technical Working Group (TWG)

Formed in 2005 Purpose: Promote Technology Transfer Facilitate Product Approval Methods Encourage Research Develop Quality and Environmental Testing Protocols Provide Guidelines for Mix Design and Construction Identify Other Benefits of WMA

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WMA TWG Accomplishments

www.warmmixasphalt.com

Material Testing Framework Emission Testing Framework WMA Best Practices Document Research Needs Identified Developed three (3) research statements Submitted through AASHTO to NCHRP • All projects highly ranked by SCOR • Total $1.4 million

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NCHRP Research Projects

NCHRP Project 09-43 “Mix Design Practices for Warm Mix Asphalt” $500,000.

00 Advanced Asphalt Technologies, LLC NCHRP Project 09-47 “Engineering Properties, Emissions, and Field Performance” $900,000.

00 Principal Investigator: Asphalt Institute WMA SCAN 2007 34

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Warm Mix Asphalt: Best Practices

Quality Improvement Series (QIP) 125 Stockpile Moisture Management Burner Adjustments and Efficiency Aggregate Drying and Baghouse Temperatures Drum Slope and Flighting Combustion Air RAP usage Placement Changes 35

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WMA US Implementation

To date trial projects have been place in over 50% of the US states. The oldest projects are now 3 to 4 years old with no indication of poor performance.

Over 500,000 tons of WMA have been placed.

Two states want to use WMA as a alternative to Hot Mix now.

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WMA US Implementation

Major concerns Potential for moisture damage.

Long term durability.

Mix design changes.

Thank You

Questions