WARM MIX ASPHALT TECHNOLOGY

Transcription

1 WARM MIX ASPHALT TECHNOLOGY Southeastern Asphalt User/Producer Group 2008 Annual Meeting November 18, 2008 Birmingham, AL Acknowledgements: John D Angelo - FHWA FHWA Mobile Asphalt Testing Laboratory Program Chuck Paugh Project Manager Jagan Gudimettla Mixture Project Engineer Satish Belagutti Binder Project Engineer Raj Dongré DLS, Inc Justin Tesch Mix Technician Joshua Thompson Mix Technician David Heidler Binder Technician Darnel Jackson Binder Technician also FHWA Turner Fairbank Highway Research Center Nelson Gibson, Scott Parobeck, Frank Davis NCHRP project Advanced Asphalt Technologies, LLC 2 WMA Investigation and Implementation Premise Although there are many factors driving the development and implementation of WMA technologies globally, in order for WMA to succeed in the U.S., WMA pavements must have equal or better performance when compared to traditional HMA pavements How Many WMA Technologies are Available in the U.S.? 3 4 How Many WMA Technologies are Available in the U.S.? Currently 14 Technologies Marketed and Available in the U.S

2 7 8 Interstate 70, Dillon, CO 70 miles West of Denver, CO Elevation 8,800 11,0 Feet East Entrance, Yellowstone, WY Dillon 9 East Entrance, Yellowstone, WY

3 MAMTL Trailer WMA Projects Location Hall St., St. Louis, MO I-70, Dillon, CO, West of Eisenhower Tunnel East Entrance Road, Yellowstone National Park, WY Warm Mix Asphalt Projects Mix Design 12.5mm Superpave 9.5mm Superpave 19mm Hveem Lab Compaction Level, Gyrations Base Binder Grade 0 PG PG Technologies Aspha-Min Evotherm Advera Evotherm 75 PG Advera Binder Characterization Objective Evaluate the effects of three Warm Mix process namely, Aspha-Min and Evotherm on M320-Table 2 To Compare the s of Warm Mix processes with the base asphalt used in preparing warm mix asphalts 13 Mobile Asphalt Mixture Testing Laboratory 14 M320 Continuous M320, Table 2 Additive Rate, by wt of binder PG Comparison - Evotherm High Temperature Low Temperature Base w/ % Continuous PG Evotherm (recovered per ASTM D 6934) 15 w/ Aspha-Min % BASF Method-BASF BASF Method-FHWA British ASTM D Asphalt Binders I-70, Dillon, CO M320 Continuous M320, Table 2 Additive Rate, by wt of binder East Entrance Rd, Yellowstone, WY M320 Continuous M320, Table 2 Additive Rate, by wt. of binder Base Base % % Aspha-Min Advera % Advera % 17 Evotherm No Data Obtained Due to Schedule 18 3

4 Findings 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 Findings Emulsion recovery processes had no effect on the PG. The PGs from all three recovery methods were found to be the same ASTM D6934 was found to be the quickest and easiest process to recover the Evotherm residue from emulsion Mixture Characterization Objectives When should WMA performance specimens be tested What are the effects of reheating on WMA performance test properties Approach Immediate Compaction / Immediate Testing Immediate Compaction / Delayed Testing Reheated Compaction and Testing St. Louis Paving Schedule Control (12.5mm PG 70-22) 5/17/06 5/18/06 5/19/06 Evotherm 5/22/06 Evotherm 5/23/06 Aspha-Min 5/25/ Sampling Truck bed every 2 hours of production Volumetric P b Ignition G mm G mb Immediate Testing E* and Fn next day after manufacture TSR and Hamburg (TFHRC) Sampling Truck bed every 2 hours of production Volumetric P b Ignition G mm G mb Delayed Testing E* and Fn testing 2-3 weeks after manufacture TSR and Hamburg (TFHRC)

5 Sampling Reheated compaction and testing conducted by TFHRC 1~2 tons mixture 15 5 gallon buckets SPT; TSR; Hamburg Nelson Gibson - TFHRC Superpave Gyratory Compactor 366 specimens fabricated over 6 days Asphalt Mixture Performance Tester Dynamic Modulus (E*) Test Temperatures 4.4º C (40º F) 21.1º C (70º F) 37.8º C (0º F) 54.4º C (130º F) Frequencies 0.1, 0.5, 1, 5,, 25 Hz IPC Global AMPT Device NCHRP Recommended Temperatures and Frequencies Temperature Frequency (Hz) Traffic Speed C F.1 SLOW FAST Master Curve Arrenhius Fit Control Mixture Hz 5 Hz 1 Hz 0.1 Hz C 21.1 C 37.8 C 54.4 C Fit 1 1.E- 1.E-08 1.E-06 1.E-04 1.E-02 1.E+00 1.E+02 1.E+04 1.E E*, ksi 00 Immediate Delayed 0 Reheated

6 Mixture 0000 Evotherm Emulsion Mixture Immediate-280 F 00 Immediate-280 F 00 Delayed-280 F Delayed-280 F Reheated-280 F Immediate-240 F 0 Reheated-280 F Immediate-240 F 0 Delayed-240 F Delayed-240 F Reheated-240 F Reheated-240 F Aspha-min Mixture 0000 Immediately Compacted Immediately Tested Immediate 00 Control Mix ºF Delayed 0 240ºF Evotherm 280ºF 0 Reheated Evotherm 240ºF Aspha-Min 280ºF Immediately Compacted Delayed Testing 0000 Reheated Compaction Delayed Testing Control Mix Control Mix 280ºF 240ºF ºF 240ºF Evotherm 280ºF 00 Evotherm 280ºF 0 Evotherm 240ºF 0 Evotherm 240ºF Aspha-Min 280ºF Aspha-Min 280ºF

7 I-70, Frisco, CO 0000 E. Entrance Rd, Yellowstone, WY Pb - 5.3%, Mix Design Replication E* - Master Curve 000 E* - Master Curve Control Mix Advera Control Mix Advera E. Entrance Rd, Yellowstone, WY Average WMA Production E* - Master Curve Control Mix Advera Flow Number, Fn Loading Axial load applied for 0.1 second with 0.9 second rest period Test Temperatures LTTPBind, Version 3.1 Software Site pavement temperature at 50% Reliability Pavement Temperature Pavement Temperature + 6 C Pavement Temperature - 6 C STRESS STRAIN TIME Flow Number CYCLES IPC Global AMPT Device Flow Number, Fn Test Temperatures 46º C (115º F) 52º C (126º F) 58º C (136º F) Loading 600 kpa Deviator Stress 0 kpa Confining Pressure Flow Number, cycles Flow Number, Fn Immediate and Delayed Test Specimens C 52 C 58 C Control T1 T2 Evotherm T1 Evotherm T2 Aspha - Min Control T1 T2 Evotherm T1 Evotherm T2 Aspha - Min Control T1 T2 Evotherm T1 Evotherm T2 Aspha - Min

8 Flow Number, Fn I-70 - Frisco, CO Test Temperatures 36º C (97º F) 42º C (8º F) 48º C (118º F) Loading 689 kpa (0 psi) Deviator Stress 69 kpa ( psi) Confining Pressure Flow Number, cycles I-70 Flow Number, Fn C 42 C 48 C Control Advera Evotherm I-70 Hamburg Advera Findings Immediate vs. Delayed Testing Evotherm & Aspha-Min Performance testing - delayed after specimen manufacture Performance testing can be conducted immediately after specimen manufacture CDOT Hamburg History: 75 gyration mixtures typically fail Hamburg, but fail primarily due to plastic flow rutting rather than stripping/moisture damage CONTROL 9.46 mm *Data and Photos are Courtesy of CODOT ADVERA 9.79 mm I-70 Hamburg I-70 Hamburg Evotherm CONTROL mm CONTROL. mm *Data and Photos are Courtesy of CODOT *Data and Photos are Courtesy of CODOT SASOBIT.49 mm Evotherm mm

9 Yellowstone Hamburg Control mm and 4.00 mm Advera mm and 3.25 mm mm and 2.60 mm *All the testing was performed at 40 C wet and reported at 20,000 passes. Yellowstone TSR Control Mixture Dry = 67 psi, Wet = 57 psi; 85% retained Advera Mixture Dry = 69 psi, Wet = 56 psi; 81% retained Mixture Dry = 76 psi, Wet = 64 psi; 84% retained Strength TSR Implementation Challenges Multiple WMA technologies (with more to come) Mix Design Procedures Conditioning temperature Binder ageing procedures Effects of reheating specimens Laboratory equipment for foamed asphalt Moisture Sensitivity Performance Equal or better than HMA!! Specification Requirements WMA Technical Working Group (TWG) 52 FHWA / NAPA sponsored Co-Chairs Matthew Corrigan, FHWA Ron White, Industry Represented State DOT AASHTO State APA Labor NCAT NIOSH Hot Mix Asphalt Industry WMA TWG Accomplishments 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 Guide Spec for Highway Construction NCHRP Research Projects NCHRP Project Mix Design Practices for Warm Mix Asphalt $500, Principal Investigator: Dr. Ramon Bonaquist, Advanced Asphalt Technologies, LLC Completion Date: March

10 55 NCHRP Project Address the increasingly wide range of WMA technologies and processes Design Mixtures Based on AASHTO M323 Materials Selection Volumetric Design Moisture Damage and Rutting Coating, Workability, Compactability Develop AASHTO Standard Practice Modified AASHTO R35 for WMA Short Term Conditioning 2 hours at compaction temperature 56 NCHRP Project NCHRP Project NCHRP Project Performance Testing Flow Number Test (Fn) Rutting Resistance based on Design ESALs Dynamic Modulus (E*) Fatigue Cracking Thermal Cracking Binder High Grade increase based on production temp Ageing Index (AI) at high PG temp (G*/sin δ) RTFOT (G*/sin δ) Tank NCHRP Research Projects NCHRP Project Engineering Properties, Emissions, and Field Performance $900, Principal Investigator: Asphalt Institute Completion Date: not to exceed 42 months WMA TWG Submissions for Future NCHRP Research Projects WMA TWG Research Needs Statements Moisture Sensitivity of Warm Mix Asphalt Technologies Short Term Ageing of WMA Binders During Production Long Term Field Performance of Warm Mix Asphalt Technologies Differences between Field Produced WMA and HMA Volumetric Properties 59 60

11 Binder ETG Research Projects Laboratory Evaluation: Wax Additives in Warm-Mix Asphalt Binder Evaluate the effect of wax additives on physical properties and characteristics of asphalt binders and their subsequent performance in mixtures. Binder ETG Research Projects Asphalt One (1) Lion Oil PG64-22 Eldorado, AR Refinery Wax Additives Nine (9) Non-Paraffin Wax Additives Aggregates Vulcan Barin Quarry Granite, Columbus, GA Mix Design 12.5mm Dense Graded SuperPave Gyratory ~5.5% Binder ~7.0% Air Voids Binder ETG Research Projects Fourier Transform Infra-Red Spectroscopy Gel Permeation Chromatography Glass Transition (Tg) Branching Physical Hardening (32 days saturation at -12 C) Bending Beam Rheometry Testing at 1,2,4,8,16 and 32 Days Multi-Step Creep Recovery (MSCR) Binder Stress Sweep Fatigue Additional testing etc Warm Mix Asphalt: Best Practices 65 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 65 WMA European Scan Tour 66 Joint Program w/ FHWA, AASHTO, NCHRP and Industry Publication FHWA-PL Scan Final Report Electronic copy.pdf available at 66 11

12 (7-0) 3 rd Ranked by AP and USA Today 12