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John A. D’Angelo US Federal Highway Administration CUPGA 2008 Saskatoon, Saskatchewan . How Many WMA Technologies are Available in the U.S.?. 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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John A. D’Angelo US Federal Highway Administration CUPGA 2008 Saskatoon, Saskatchewan
How Many WMA Technologies are Available in the U.S.? Currently 12 Technologies Actively Marketed and Available in the U.S.
Warm Mix Trials and Demonstrations Trial completed
There is a tremendous growth in interest in Warm Mix in the US • WHY? • Fuel costs are up. • Bitumen cost have spiked.
Change in Producer Prices for Construction Segments Source: BLS (CPI, PPI)
Change in Producer Price Indexes (PPI) for Highway Inputs Source: BLS (CPI, PPI)
Economic Drivers for Using RAP • Growth in recycling occurs when it is economical to do so. • Warm Mix Technology can improve RAP workability.
A review of some projects and what we have learned • Hall Street St. Louis • I70 Colorado • Entrance to Yellowstone
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
Interstate 70, Dillon, CO 70 miles West of Denver, CO Elevation 8,800 – 11,100 Feet Dillon
Interstate 70, Dillon, CO * Minimum delivery temp for control HMA was 280 °F Chart is Courtesy of CODOT
Construction Highlights * 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
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
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.
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
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
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
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
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
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
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
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
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.
WMA US Implementation • Major concerns • Potential for moisture damage. • Long term durability. • Mix design changes.
Thank You Questions