Presentation on theme: "John A. D’Angelo US Federal Highway Administration CUPGA 2008 Saskatoon, Saskatchewan."— Presentation transcript:
John A. D’Angelo US Federal Highway Administration CUPGA 2008 Saskatoon, Saskatchewan
2 How Many WMA Technologies are Available in the U.S.?
3 Currently 12 Technologies Actively Marketed and Available in the U.S. How Many WMA Technologies are Available in the U.S.?
5 Warm Mix Trials and Demonstrations Trial completed
6 There is a tremendous growth in interest in Warm Mix in the US WHY? Fuel costs are up. Bitumen cost have spiked.
7 Change in Producer Prices for Construction Segments Source: BLS (CPI, PPI)
8 Change in Producer Price Indexes (PPI) for Highway Inputs Source: BLS (CPI, PPI)
9 Change in Producer Price Indexes (PPI) for Asphalt
10 Economic Drivers for Using RAP Growth in recycling occurs when it is economical to do so. Warm Mix Technology can improve RAP workability.
11 Fractionated RAP
13 A review of some projects and what we have learned Hall Street St. Louis I70 Colorado Entrance to Yellowstone
14 Hall Street, St. Louis, MO
15 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
16 Interstate 70, Dillon, CO Dillon 70 miles West of Denver, CO Elevation 8,800 – 11,100 Feet
17 Mix Type Field Property Control Advera WMA Control Sasobit Control Evotherm Low Air Temp. (°F) Delivery Temp. (°F) *260*235*243 At Screed Temp. (°F) *243*230*235 Mat Density (% Rice) (single data point) * Minimum delivery temp for control HMA was 280 °F Chart is Courtesy of CODOT Interstate 70, Dillon, CO
18 Construction Highlights Mix Type Property Control Advera WMA Control Sasobit Control Evotherm Results are from the CDOT QA lab – QC results were comparable FHWA’s mix flow number, dynamic modulus and binder test data are pending. AC (%) Voids (%) VMA (%) Mat Density (% Rice) ~94 TSR (%) 10083* Stability Hamburg (mm rut) * 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
19 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
20 East Entrance, Yellowstone, WY
25 Mixture Locations
26 Control mm and 4.00 mm Advera mm and 3.25 mm Sasobit mm and 2.60 mm *All the testing was performed at 40°C wet and reported at 20,000 passes. Yellowstone Hamburg
27 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
28 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 Binder Characterization
29 Hall Street, St. Louis, MO M320 Continuous Performance Grade M320, Table 2 Performance Grade Additive Rate, by wt of binder Base 70.9 – w/ Sasobit 76.5 – % w/ Aspha-Min 72.4 – % Evotherm (recovered per ASTM D 6934) 66.6 –
30 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
31 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
32 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
33 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 Accomplishments
34 NCHRP Research Projects NCHRP Project “Mix Design Practices for Warm Mix Asphalt” $500, Advanced Asphalt Technologies, LLC NCHRP Project “Engineering Properties, Emissions, and Field Performance” $900, Principal Investigator: Asphalt Institute 34 WMA SCAN 2007
35 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
37 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.
38 WMA US Implementation Major concerns Potential for moisture damage. Long term durability. Mix design changes.