1 / 31

Bituminous Street Re-certification

Bituminous Street Re-certification. Specification Discussion. (2360) PLANT MIXED ASPHALT PAVEMENT Combined 2360/2350 (Gyratory/Marshall Design) Specification. Implemented in 2003 as a new stand-alone specification. Includes both Marshall and Gyratory (Superpave) design.

fitzgerald-hahn
Télécharger la présentation

Bituminous Street Re-certification

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Bituminous Street Re-certification Specification Discussion

  2. (2360) PLANT MIXED ASPHALT PAVEMENTCombined 2360/2350 (Gyratory/Marshall Design) Specification • Implemented in 2003 as a new stand-alone specification. Includes both Marshall and Gyratory (Superpave) design. • Complete re-write of 2331 and 2340 and a combining of 2350 and 2360. • Changed mixture designations • Included VMA, TSR, F/A • Increased Density Requirements • Included Ride Requirement • Removed methodology of 2331 and 2340 • Includes Incentives/Disincentives.

  3. Over a Decade of Changes • Hot Mix Asphalt Specifications in Minnesota have changed dramatically since 1988. • In 1988, Quality Management Specification 2340 • In 1997, PG Grading System Implemented • In 1998, 2350 (Marshall) and 2360 (Superpave) • In 2003, 2360 Combined Marshall and Superpave Specification.

  4. Why the Changes? • Agency staffing and philosophy changes have put more responsibility with the Contractor (QC/QA). • Agency/Industry partnership • The need for more durable mixtures. • Superpave (Gyratory) • Increased traffic and loadings • Engineered mixtures • Better understanding of HMA design. • New technology.

  5. Pavement Distress in Minnesota

  6. Our Goal

  7. 2360 Combined 2360/2350 (Gyratory/Marshall Design) • Durability Through…. • Improved Material Requirements • Improved Design Requirements • QC/QA • Improved Density Requirements • Improved Smoothness Requirements

  8. Material Requirements • PG Asphalt Selection • Mineral Aggregate -- provides the stone skeleton to support and carry the load. • Aggregate Properties • Los Angeles Rattler • Magnesium Sulfate Soundness • Spall Material • Gradation Requirement • Crushing

  9. Today’s Typical Cold Feed Setup

  10. Design Requirements • Volumetrics • Air Voids (gyratory compactor) • Asphalt Content • VMA • Moisture Susceptibility • TSR • Fines/Effective Asphalt

  11. Quality Control/Quality Assurance • Agency/Industry Partnership • Certified Plant • Production Test Results • Air Voids • Asphalt Content • Gradation • Crushing • VMA

  12. One of the Biggest Differences Between Now and Then…. • Complexity of the Specifications… • Production Control with Old Specification • Acceptance on per test basis • Spotcheck and gradation • Production Control with Current Specification • Acceptance on individual and moving average test results • Volumetrics • Air voids, VMA, Asphalt content • Gradation • Crushing • Density • Ride

  13. Incentive/Disincentive • Density and Ride • Incentive Purpose: • To encourage the contractor to provide workmanship and a final product above and beyond the minimum contract requirements. • Anticipated Direct Benefits of Incentive: • Longer service life • Reduced maintenance costs • Allows the better Contractor to bid in the incentive and possibly end up low bidder. • Incentives must be paid in a timely manner.

  14. Incentive/Disincentive • Historically, penalties haven’t gotten us what we want. Penalties don’t equate to quality. Penalties are difficult to collect. • I/D provision has set the bar higher. Statistically, 1/3 of results will be at 100% pay and 2/3 will be above or below 100% pay.

  15. Incentive Costs* • Density will typically add $0.15/ton of mix • Ride will typically add $0.45/ton of mix * Based on TH data from 1998 - 2003

  16. Before the Project Starts… • Review plans, proposal, and special provisions. • Familiarize yourself with: • Typical sections • Different mixes, widths, thicknesses, etc. • Inspector/Job Superintendent should discuss sequence of operations and agree on a system of communication.

  17. 2360Combined 2360/2350 (Gyratory/Marshall Design) Specification • Includes Marshall and Gyratory design. • Mixture Designation convention: • Ex. For Marshall: • LVWE35030C • Ex. For Gyratory: • SPWEB540F • Pay Item convention: • Ex. 2350.609 Type LV 3 Wearing Course C • Ex. 2360.609 Type SP 12.5 Wearing Course (5,F)

  18. 2360/Superpave Designation Max Size A (SP 9.5mm) -1/2” B (SP 12.5mm) -3/4” C (SP 19.0mm) -1” 2360/Marshall Designation Max Size 4 -1/2” 3 -3/4” 2 -1” 5 -3/8” Gradation Sizes

  19. 2360Combined 2360/2350 (Gyratory/Marshall Design) Specification • Air Void Requirements

  20. (2360) PLANT MIXED ASPHALT PAVEMENTCombined 2360/2350 (Gyratory/Marshall Design) Specification • Section 2360.4 J, JMF Adjustment • Requires the Contractor to start production with all aggregate proportions included on the Mix Design Report unless the aggregate proportion is shown as 0 % (add rock/add sand provision).

  21. (2360) PLANT MIXED ASPHALT PAVEMENTCombined 2360/2350 (Gyratory/Marshall Design) Specification • Shoulder Density Requirement • Specification defaults to Ordinary Compaction when shoulder is 6 feet wide or less. • Specification defaults to Maximum Density when shoulder is wider than 6 feet. • Check Special Provisions for specific Contract requirements.

  22. (2360) PLANT MIXED ASPHALT PAVEMENTCombined 2360/2350 (Gyratory/Marshall Design) Specification • Density Incentive Modification • Incentive for density allowed when the “day’s weighted average production air voids are less than 0.5% from the target air void”. Used to be based on individual air void for that lot.

  23. Random number location and actual coring location

  24. Waiving reduced density provision • Specification defaults to 1% reduced density from minimum required density when: • First lift on PCC • First lift on aggregate base, reclaimed or cold inplace recycled, or first lift on roadway with 7 ton or less spring load restriction. • Incentive payment is excluded on reduced density • Contractor can request reduced density be waived (must be approved by Engineer) • Incentive payment will be made if reduced density waived • First lift reduced density on PCC not allowed • Request and approval must be made after 1st day paving and before 3rd days paving begins. • Incentive/Disincentive payment goes back to include 1st day paving

  25. (2360) PLANT MIXED ASPHALT PAVEMENTCombined 2360/2350 (Gyratory/Marshall Design) Specification • Thickness and Surface Smoothness Requirements. • 1/4” tolerance for surface measured with straightedge laid parallel or at right angle to centerline.

  26. (2360) PLANT MIXED ASPHALT PAVEMENTCombined 2360/2350 (Gyratory/Marshall Design) Specification • Smoothness General • Contractor and Agency must mutually agree on scheduling of smoothness testing so that Agency can be present to observe testing. • Unless otherwise approved, any testing performed without Agency presence can be ordered re-tested.

  27. Bituminous Web Page www.mrr.dot.state.mn.us/pavement/bituminous/bituminous.asp

  28. Web Page Contents • Bituminous Specifications and Highlights • Bituminous Laboratory Procedures, Field Procedures and Lab Manual • Spread Sheets and Other Tools • Design Aids and Miscellaneous Documents • Miscellaneous Forms • People and Phone Numbers

  29. Confusion about the new 2360 ?? • Need Help, Contact: • State-Aid • District Materials • Bituminous Office

  30. Bituminous Office Phone #’s • John Garrity (651)779-5577 • Dan Boerner 779-5582 • Dave Linell 779-5614 • Joseph Thomas 779-5619 • (Trial Mix Lab) 779-5621 • Fax 779-5580

  31. Questions ??

More Related