SUPERPAVE. SUperior PERforming Asphalt PAVEments. History of Hveem Mix Design

Transcription

1 SUPERPAVE SUperior PERforming Asphalt PAVEments History of Hveem Mix Design Hveem mix design was created by Francis Hveem in the 1920 s Basic premise of the design methodology is to coat each aggregate particle with an optimal amount of binder. Methodology updated by Hveem in the 1950 s to account for traffic loadings. 1

2 Limitations of Hveem Mix Design Mix design based on 1950 s traffic loading Todays Traffic Loading 2

3 Limitations of Hveem Mix Design Does not take into account: Weather/Environmental conditions Binder properties PG grading Polymer Modified Rubber Changing quality of aggregates New testing criteria Why Change Traffic volumes and loading have skyrocketed Axle configurations have changed Super single Increased tire pressure (pizza cutters) Quality aggregate sources are dwindling PG Binder grading Mechanistic Empirical design HMA volumetrics 3

4 Why Change Testing equipment availability Hveem Compactors Stabilometers Why Change Old dry pavement 4

5 Why Change Rutting Why Change Traffic 5

6 Implementation plan Time Line Implement approximately 6 pilot projects Revise Superpave specification Implement 12 to 16 pilot projects Revise Superpave specification 2014 Full implementation Immediate Impacts Cities and Counties 6

7 Current Project List Superpave Pilot Projects District EA County/Route PM Est. Ad Date Est. Bid Open By Tons/Type 04 3E4401 CC /5.8 RTL 1/13 Bid Pkg 04 0A5344 Sol /12.9 RTL 1/13 Bid Pkg 04 2G5104 CC /32.4 RTL 1/13 Bid Pkg CC /15.1 RTL 1/13 Bid Pkg 04 0A0801 CC /5.3 RTL 10/12 Bid Pkg E4 Mon 101 In Construction CCO Tul /2.9 8/1/2012 9/1/12 Bid Pkg 07 3Y3001 LA /19.4 In Construction Bid Pkg 07 3Y9401 LA /30.5 In Constuction Bid Pkg LA /48.6 9/1/ /1/12 Bid Pkg 08 0K2300 SBd /R53.0 9/3/2012 Bid Pkg 08 0P8601 SBd 10 R57.6/R /15/13 Bid Pkg 40,000 RHMA; 500 HMA 12,530 RHMA; HMA 3,490 RHMA; 10,480 HMA 3,160 RHMA; 22,000 HMA 1265 RHMA; HMA 50,000 HMA Type A 14,000 HMA Type A 9,280 RHMA G 5,200 RHMA G WMA LSM 25,200 RHMA G 9,940 RHMA G 36,000 RHMA G INY NB RTL 1/13 Bid Pkg 20, M8004 Tul /38.7 Complete 8/1/12 CCO 31,247 HMA Type A Imp /31.3 1/3/12 4/1/12 Bid Pkg Superpave Equipment Pine SGC Model AFG2A Troxler SGC Model

8 Superpave Equipment Hamburg Wheel Tracker (HWT) Inside View Hamburg Wheel Tracker (HWT) Overview Pilot projects will be Standard Process Caltrans material testers will be using National Standards (AASHTO/ASTM) Independent Assurance will be testing and witnessing field and lab material testers 8

9 Superpave and the Caltrans IA Program Effects to the IA Program No change in current requirements in: Accrediting laboratories Certifying Technicians Change in IA practice: Familiarize with both AASHTO and CT Test Methods Grandfather AASHTO with equivalent CT Test Certification CTM = Certificate of Proficiency (TL-0111) AASHTO = witness statement (development stage) Superpave AASHTO/ASTM vs CTM AASHTO/ ASTM Description (Aggregate Tests) CTM T 11 Materials Finer Than 75-μm (No. 200) Sieve in Mineral Aggregates by Washing 201, 202 T 27 Sieve Analysis of Fine and Coarse Aggregates 201, 202 T 30 Mechanical Analysis of Extracted Aggregate 201, 202 T 335 Determining the Percentage of Fracture in Coarse Aggregate 205 T 84 Specific Gravity and Absorption of Fine Aggregate 207 T85 Specific Gravity and Absorption of Coarse Aggregate 206 T 176 Plastic Fines in Graded Aggregates and Soils by Use of the Sand Equivalent Test 217 T 304 Uncompacted Void Content of Fine Aggregate 234 D 4791 Flat Particles, Elongated Particles, or Flat and Elongated Particles in Coarse Aggregate1 Grandfather Yes 235 No 9

10 Superpave AASHTO/ASTM vs CTM AASHTO/ ASTM T 209 T 269 T 275 T 283 T 308 T 312 Description (Mix Test) Theoretical Maximum Specific Gravity and Density of Hot Mix Asphalt (HMA) Percent Air Voids in Compacted Dense and Open Asphalt Mixtures Bulk Specific Gravity of Compacted Hot Mix Asphalt (HMA) Using Paraffin-Coated Specimens Resistance of Compacted Hot Mix Asphalt (HMA) to Moisture- Induced Damage Determining the Asphalt Binder Content of Hot Mix Asphalt (HMA) by the Ignition Method Preparing and Determining the Density of Hot Mix Asphalt (HMA) Specimens by Means of the Superpave Gyratory Compactor CTM Grandfather Yes , None T 324 Hamburg Wheel-Track Testing of Compacted Hot Mix Asphalt (HMA) None T 329 Moisture Content of Hot Mix Asphalt (HMA) by Oven Method 370 No Superpave New Test Methods AASHTO M 323 Volumetric requirements AASHTO R 35 Mix Design evaluation SP 2 SUPERPAVE Mix Design Handbook AASHTO R 30 Mixture Conditioning AASHTO T 312 SGC Mixture Compaction Volumetrics Air Voids, VMA, VFA AASHTO T 324 Hamburg Test 10

11 Superpave Laboratory Accreditation Current requirements from IA Manual still apply Participation in Caltrans RSP Submittal of CLAM Laboratory inspection New requirements AMRL Participation AASHTO accreditation Superpave Laboratory Equipment Calibration Requirements for SGC and HWT Annual Calibration Calibration performed by Manufacturer Or Outside company Calibration verification Performed by Caltrans IA Laboratory Staff 11

12 JMF Development: New Forms: 3511SP 3512 SP 3513SP Forms can be found at: dex.htm OBC is specified by Total Weight of Mix Work sheets are available at ndex.htm 12

13 JMF Design: Aggregate AASHTO T335 CT205 Percent of crushed particles HMA SP RHMA SP OGFC Coarse aggregate (% min.) One fractured face Two fractured faces Fine aggregate (% min) (Passing No. 4 sieve and retained on No. 8 sieve.) Two fractured faces

14 JMF Design: Aggregate Los Angeles Rattler (% Max loss) AASHTO T69 CT211 Sand Equivalent AASHTO T176 CT217 Average of 3 tests from same sample FAA AASHTO T304 Flat and Elongated ASTM D4791 JMF Design: RAP 25% +/ 1% at JMF Design, +/ 3% during producti0n RAP fractionated into: + #4 Sieve #4 Sieve Allowable stockpile variance, binder content: +/ 2.0% Sieve correction factors & binder content Binder content* ASTM 2172 Grading RAP CT

15 JMF Design: RAP Rice Specific Gravity AASHTO T209 CT309 Allowable stockpile variance G mm = +/ Ignition oven* AASHTO T309 CT382 * Requires 3 samples JMF Design: RAP HMA mixtures with RAP Maximum binder replacement is 25.0 percent for surface course and 40.0 percent for lower courses. Surface course is defined as the upper most 0.2 feet HMA with a binder replacement percent less than or equal to 25% of OBC, you may bump down 1 grade. HMA with a binder replacement greater than 25% and less than or equal to 40% OBC, mandatory bump down 1 grade 15

16 JMF Design All laboratories performing any part of HMA mix designs must be qualified under AMRL, and CT Independent Assurance program HMA & RHMA mix design AASHTO R35 CT367 AASHTO M323 does not apply OGFC CT368 Mix Design performed by Caltrans JMF Design: OBC Gyrations Compaction AASHTO T 312 HMA SP RHMA SP G Ninitial =8 Ndesign = Ndesign =85 Nmax =130 Air Voids (+/ 0.5%) AASHTO T 269 HMA SP RHMA SP G Ninitial =8.0% Ndesign =Specifications Ndesign =4.0% Nmax =2.0% CT367 16

17 JMF Design: Volumetrics VMA SP 2 LP 2 Grading Type A RHMA SP G No / ½ ¾ JMF Design: Volumetrics VFA SP 2 LP 3 Grading Type A RHMA SP G No Report Only 3/ Report Only ½ Report Only ¾ Report Only 17

18 JMF Design: Volumetrics Dust Proportion SP 2 LP 4 Grading Type A RHMA SP G No. 4 and 3/ Report Only 1/2" and ¾ Report Only JMF Design: Moisture sensitivity/rutting/raveling AASHTO T324 Plant produced material Maximum rutting depth: 0.5 Binder Grade Type A RHMA SP G PG 58 10,000 15,000 PG 64 15,000 20,000 PG 70 20,000 25,000 PG 76 25,000 18

19 Moisture sensitivity/rutting/raveling AASHTO T324 10,000 passes minimum for inflection point JMF Design: Moisture Susceptibility AASHTO T 283 CT371 Plant produced material Minimum dry strength 120 psi Minimum TSR 70% Gyratory prepared samples 4 or 6 specimens Freeze/Thaw conditioning is optional Required for HMA SP & RHMA SP G 19

20 JMF Design: Plasticity Index (PI): If either T283 or T324 do not meet minimum quality requirements you must test for PI. For RHMA SP G: if the tensile strength ratio test result for treated plant produced RHMA G SP is less than the hot mix asphalt mix design requirement for tensile strength ratio, the minimum tensile strength ratio requirement is waived, but you must use any of the following antistrip i treatments: You must still meet dry strength value For AASHTO T324, submit test data and 1 tested sample set to the Engineer within 7 days of sampling. JMF Design: For RHMA SP G you may increase SGC pressure to a maximum of 825 Kpa (120 psi) For RHMA SP G you may hold specimen at constant height for a maximum of 90 minutes 20

21 JMF Verification: For JMF verification, use the optimum binder content specified on your CEM 3512SP, no adjustments are allowed. When RAP is used, binder set point for HMA must be the optimum binder content specified on the CEM 3512SP minus the percent RAP multiplied by the combined average binder content of the processed fractionated RAP stockpiles. JMF Verification: For VMA, VFA and DP, HWT & T283: Testing is on Plant Produced Material HMA quality specified in the table titled "Hot Mix Asphalt Mix Design Requirements Binder Content (HMA ±0.3 percent, RHMA ±0.4 percent) Air voids content (design value ± 1.5 percent) Void in Mineral Aggregate (13.5+3/ 1) for ¾ Grading Voids filled with asphalt (design value +/ 1.0 percent) Dust proportion (design value +/ 0.5) 21

22 JMF Verification: The State will verify up to 2 proposed JMF s for each binder and aggregate specified. Each additional verification will cost $3000. (Engineers option) The Engineer will verify 1 binder source change per approved JMF. The cost will be $2000 JMF Verification: If you do not verify you may: Change Asphalt binder content target value up to ±0.2 percent from the optimum binder content. For RHMA SP G, OBC may not be below 7.5 by TWM Change aggregate target values, but must be within target value limits 22

23 Construction: Quality Control Requirements Percent of theoretical maximum density (%) by core CT 375: 2 per paving day minimum Type A RHMA SP G Construction: Quality Control Requirements Percent of theoretical maximum density by Nuclear gauge (%) CT 375: 3 per 250 tons but not less than 3 per paving day Type A RHMA SP G Verify gauge correlation to cores every 10,000 tons utilizing the average of 2 cores 23

24 Construction: Quality Control Requirements Hamburg Wheel Test AASHTO T324: One per 10,000 tons or 1 per project whichever is more Maximum rutting depth: 0.5 /Minimum inflection point: 10,000 Binder Grade Type A RHMA SP G PG 58 10,000 15,000 PG 64 15,000 20,000 PG 70 20,000 25,000 PG 76 25,000 Construction: Quality Control Requirements Moisture Susceptibility AASHTO T283: One per 10,000 tons or 1 per project whichever is more Minimum dry strength 120 psi Minimum TSR 70% Required for HMA SP & RHMA SP G 24

25 on the Horizon Expanded definition of Commercial Mix Limit tonnage placed to about 6,000 tons Require some materials testing Grading Volumetrics Binder content Mix Design QA Quality HMA sampling QC 25