温拌沥青混合料国外讲座.ppt

John A. D’Angelo US Federal Highway Administration CUPGA 2008 Saskatoon, Saskatchewan 2How Many WMA Technologies are Available in the U.S.?3Currently 12 Technologies Actively Marketed and Available in the U.S.How Many WMA Technologies are Available in the U.S.?45Warm Mix Trials and DemonstrationsWarm Mix Trials and DemonstrationsTrial completed 6There is a tremendous growth in interest in Warm Mix in the US• WHY?–Fuel costs are up.–Bitumen cost have spiked.7Change in Producer Prices for Construction Segments Source: BLS (CPI, PPI)8Change in Producer Price Indexes (PPI) for Highway InputsSource: BLS (CPI, PPI)9Change in Producer Price Indexes (PPI) for Asphalt10Economic Drivers for Using RAP• Growth in recycling occurs when it is economical to do so. • Warm Mix Technology can improve RAP workability.11Fractionated RAP1213A review of some projects and what we have learned • Hall Street St. Louis • I70 Colorado • Entrance to Yellowstone 14Hall Street, St. Louis, MO15St. 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 – 5/25/0616Interstate 70, Dillon, CODillon70 miles West of Denver, COElevation 8,800 – 11,100 Feet17MixTypeField PropertyControl7-24-07 Advera WMAControl7-26-07 SasobitControl8-13-07 EvothermLow Air Temp. (°F)545450503636Delivery Temp. (°F)*260*235*243At Screed Temp. (°F)*243*230*235Mat Density (% Rice)93.893.395.7 (single data point)93.293.794.7* Minimum delivery temp for control HMA was 280 °FChart is Courtesy of CODOTInterstate 70, Dillon, CO18Construction HighlightsMix TypePropertyControl7-24-07 Advera WMAControl7-26-07 SasobitControl8-13-07 EvothermResults are from the CDOT QA lab – QC results were comparable FHWA’s mix flow number, dynamic modulus and binder test data are pending.AC (%)6.236.386.416.326.046.38Voids (%)3.11.83.02.43.62.2VMA (%)16.515.716.515.916.315.8Mat Density (% Rice)~94~94~94~94~94~94TSR (%)10083*971119480Stability363435363534Hamburg (mm rut)9.469.7917.3110.4910.1014.86* 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 pictures19Conclusions• 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 HMA20East Entrance, Yellowstone, WY2122232425Mixture Locations26• 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.Yellowstone Hamburg27FLH-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 binder28Objective• 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 Characterization29Hall Street, St. Louis, MOM320 Continuous Performance GradeM320, Table 2 Performance GradeAdditive Rate, by wt of binderBase70.9 – 24.870.9 – 24.870 - 2270 - 22w/ Sasobit76.5 – 22.876.5 – 22.876 - 2276 - 221.5%w/ Aspha-Min72.4 – 24.672.4 – 24.670 - 2270 - 225.26%Evotherm (recovered per ASTM D 6934)66.6 – 26.766.6 – 26.764 - 2264 - 2230Findings •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 grade31Cost 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 200732WMA Technical Working Group (TWG)• • Formed in 2005Formed in 2005 • • Purpose:Purpose:– –Promote Technology TransferPromote Technology Transfer– –Facilitate Product Approval MethodsFacilitate Product Approval Methods– –Encourage ResearchEncourage Research– –Develop Quality and Environmental Testing Develop Quality and Environmental Testing ProtocolsProtocols– –Provide Guidelines for Mix Design and Provide Guidelines for Mix Design and ConstructionConstruction– –Identify Other Benefits of WMAIdentify Other Benefits of WMA33• • 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 。