温拌沥青混合料国外讲座.ppt

1、John A. DAngelo 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.,How Many WMA Technologies are Available in the U.S.?,Warm Mix Trials and Demonstrations,Tria

2、l 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),Change in Producer

3、Price Indexes (PPI) for Asphalt,Economic Drivers for Using RAP,Growth in recycling occurs when it is economical to do so. Warm Mix Technology can improve RAP workability.,Fractionated RAP,A review of some projects and what we have learned,Hall Street St. Louis I70 Colorado Entrance to Yellowstone,Ha

4、ll Street, St. Louis, MO,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,Dillon,70 miles West of Denver, CO Elevation 8,800 11,100 Feet,* Minimum delivery temp for control HMA wa

5、s 280 F,Chart is Courtesy of CODOT,Interstate 70, Dillon, CO,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

6、 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

7、 to HMA,East Entrance, Yellowstone, WY,Mixture Locations,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 40C wet and reported at 20,000 passes.,Yellowstone Hamburg,FLH-What Have We Learned,Field density achieved in all cases

8、Saved 20% in fuel at the plant Temperature at plant hard to regulate Mix handled similarly Workers noted no handling difficulties No smoke Additives dont seem to affect mix design Sasobit stiffens binder,Objective,Evaluate the effects of three Warm Mix process namely Sasobit, Aspha-Min and Evotherm

9、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,Binder Characterization,Hall Street, St. Louis, MO,Findings,Sasobit increase of one high temp. PG grade Aspha-Min - no effect on PG grade Evotherm recov

10、ered 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

11、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

12、 Construction Identify Other Benefits of WMA, 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,WMA TWG Accomplish

13、ments,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,34,WMA SCAN 2007,Warm Mix

14、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 5