trb expert task group for superpave mixtures and aggregates - updatespave/old/technical info... ·...
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TRB Expert Task Group for Superpave Mixtures and Aggregates - Update
TRB Expert Task Group for Superpave Mixtures and Aggregates - Update
Jim MusselmanFlorida Department of Transportation
Role of the ETGRole of the ETG! Provide technical advice to the TRB Superpave
Committee on mixture and aggregate issues;! Provide technical input on FHWA Superpave mixture
and aggregate projects;! Identify potential improvements to mixture and
aggregate specifications/test methods;! Identify needed standards; and! Provide a forum for government/industry discussion of
emerging issues
State MembersState Members! Jimmy Brumfield Mississippi DOT! Lon Ingram Kansas DOT! Eric Harm Illinois DOT! Rick Harvey Wyoming DOT! Judie Ryan Wisconsin DOT! Wade McClay Maine DOT! Karl Frick California DOT! Jim Musselman Florida DOT! Julie Nodes Arizona DOT (Rubber-R-Us)
Industry MembersIndustry Members! Erv Dukatz Mathy Construction Co.! Frank Fee Citgo Asphalt Co.! Jay Winford Louisiana Roads and Bridges! Gerry Huber Heritage Research Group! Todd Lynn APAC, Inc.! Adam Hand Granite Construction! Chuck Marek Vulcan Materials Co.! Ron Sines P. J. Keating Co.
Members (cont’d)Members (cont’d)! Kevin Hall University of Arkansas! Richard Kim North Carolina State University! Mike Anderson Asphalt Institute! John Bukowski FHWA
Tom Harman! Dave Newcomb NAPA
Current ActivitiesCurrent Activities!AASHTO Subcommittee on Materials Issues!Superpave Gyratory Compactor!QC/QA Proposed Standard Practice!Aggregate Issues!Simple Performance Test
Subcommittee on MaterialsSubcommittee on Materials! Changes to MP-2, PP28
Elimination of the Restricted ZoneNew 4.75 mm mixChanges well-received through Technical Section
– Forwarded on to Full Ballot ! Changes to T312
Addition of Dynamic Angle Validation option– Negative comments relating to “required” manufacturer maintenance– Change to “recommended” manufacturer maintenance
Forwarded on to Full Ballot & Approved! New Dynamic Angle Validation procedure
Balloted and Approved
Subcommittee on MaterialsSubcommittee on Materials! Provisional Standards
TP7 Superpave Shear TesterTP8 Beam FatigueTP9 Indirect Tensile Test
! Recently balloted and approved as full standards! Task Team will review and identify necessary changes
Led by Richard Kim (NC State)! Dynamic modulus test procedure balloted and approved as a
provisional standard! APA test procedure balloted and approved as a provisional
standard Needs work….
Superpave Gyratory CompactorSuperpave Gyratory Compactor! Dynamic Angle Validation Task Force
Studies indicate internal angle of 1.16°± 0.02° can reduce bias among compactors
– Not a “cure-all”Working on the development of a Guidance Statement on the use of the DAVRuggedness Evaluation
– Currently on-goingDevelopment of Precision/Bias statement
– Future….
DAV Ruggedness StudyDAV Ruggedness Study
TroxlerTroxler Electronics, Inc.Electronics, Inc.
Mixture stiffnessMixture stiffnessAsphalt InstituteAsphalt InstituteTroxlerTroxler 41414141NCATNCAT
Sample/provide mixesSample/provide mixesAPAC Material ServicesAPAC Material Services
Pine G1Pine G1Pine Instruments, Inc.Pine Instruments, Inc.TroxlerTroxler 4140 B4140 BFlorida DOTFlorida DOTBrovoldBrovoldFHWAFHWA
Pine AFGC125XPine AFGC125XTroxlerTroxler 4140 A4140 A
Univ. of ArkansasUniv. of Arkansas
SGC Model / SGC Model / ResponsibilityResponsibility
Participating LaboratoryParticipating Laboratory
Superpave Gyratory CompactorSuperpave Gyratory Compactor!Mold Wear
Identified by NCAT during Alabama DOT DAV study– Internal angle was properly calibrated– Noted variations in air voids
Source of problem found to be excessive mold wearMold diameter typically checked at top and bottom
– Not in area of wearPossible solutions identified
QC/QA Proposed Standard PracticeQC/QA Proposed Standard Practice!Based on NCHRP 9-7 work!Developed by:
Gerry Huber (Heritage) Lee Gallivan (FHWA Indiana Division)
!ETG reviewed and provided comments to QC/QA Task Team
Will be finalized at this meeting
Fine Aggregate AngularityFine Aggregate Angularity! Discussed original SHRP data on FAA
Is criteria set at appropriate level?Are 100% crushed materials unnecessarily excluded?Some states not using FAAShould 100% crushed materials be exempt?
! Compacted Aggregate Resistance (CAR) TestPossible solution?
! Task Team to look into issue furtherLed by Chuck Marek (Vulcan Materials)
Compacted Aggregate Resistance (CAR) Test
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34
Penetration (.01 in)
She
ar R
esis
tanc
e (lb
s)
Slag (47.0)
Indiana DOT Fine Aggregate Angularity Study
St. Sand(45.1)Cr.Gr.(49.0)
St. Sand(47.2)
St. Sand(44.2)
Dolomite(48.1)
Natural Sand(38.7)
Natural Sand(39.6)
Simple Performance TestSimple Performance Test! NCHRP 9-19
Recommended three test procedures– Dynamic Modulus– Creep Test (Flow Time)– Repeated Load Permanent Deformation Test (Flow Number)
! NCHRP 9-29Developing equipment specificationsFirst article procurement
– Simple Performance test ($25k - $45k)– Automated specimen fabrication system ($12k)
Equipment evaluation – early 2003
Thank You!Thank You!
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