A Mix Design Manual for Hot Mix Asphalt

The Superpave performance-based mix design system described in the Strategic Highway Research Program (SHRP) Report SHRP-A-407, "The Superpave Mix Design Manual for New Construction and Overlays," provides three levels of design. Level 1 is a volumetric design procedure based on gyratory compaction; it is implemented as AASHTO Specification MP 2, "Superpave Volumetric Mix Design," and Practice PP 28, "Superpave Volumetric Design for Hot Mix Asphalt." The Level 2 and Level 3 design procedures are intended to test and refine Level 1 designs for situations with high traffic volume and load or other severe service factors. Performance characteristics of hot mix asphalt (HMA) specimens prepared in accordance with the Level 1 procedure are evaluated with the Superpave shear test device and the indirect tensile test device methods (AASHTO Provisional Methods TP7 and TP9, respectively). These test results are then input, along with traffic, climate, and structural data, to a suite of performance models for materials characterization, pavement response, and distress prediction, and the predicted distress levels are used to determine an optimum mix design. The Level 2 and 3 design procedures were not widely or fully implemented because of serious limitations in the original SHRP performance models for permanent deformation and fatigue cracking as well as other factors. A comparable suite of HMA performance models calibrated and validated with LTPP data was recently produced in NCHRP Project 1-37A, "Development of the 2002 Guide for the Design of New and Rehabilitated Pavement Structures: Phase II." The material properties required for these models are measured with the dynamic modulus and indirect tensile tests. The availability of these performance models and associated software offers the opportunity to prepare a full working version of an HMA mix design procedure in the form of a practical manual for engineers and technicians that is comparable in its key features to the performance-based Superpave system originally envisioned by SHRP. Further, such a procedure, by using a common set of materials characterization tests and performance models to design HMA mixes that satisfy material property requirements of specific pavement structural designs prepared in accordance with the Project 1-37A pavement design guide, would represent a significant step toward the goal of integrating HMA mix design with pavement structural design. The objective of this research is to develop an improved mix design procedure for hot mix asphalt (including dense-graded, open-graded, and gap-graded mixes) in the form of a manual of practice for use by engineers and technicians in the public and private sectors. The mix design procedure will make use of the best-available materials-testing and performance-prediction technology to produce durable, distress-resistant mix designs tailored to the requirements of specific pavement layers. At a minimum, development of the design procedure shall consider (1) the volumetric design method in AASHTO MP 2 and PP 28, (2) the simple performance test(s) (SPT) and equipment recommended by NCHRP Projects 9-19 and 9-29, (3) the hot mix asphalt (HMA) materials characterization tests and performance models developed in NCHRP Project 1-37A, (4) any improved method for measuring moisture susceptibility developed through NCHRP Projects 9-34 and 9-37, and (5) any other sound, applicable research products from, for example, NCHRP Projects 1-42, 9-9(1), 9-16, 9-17, 9-22, 9-25, 9-27, 9-31, 9-36, and 9-38. The mix design manual should follow the general format of Asphalt Institute Manual SP-02, "Superpave Mix Design," and be prepared in the form of an interactive CD-ROM.


  • English


  • Status: Completed
  • Contract Numbers:

    Project 9-33

  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  USA  20590

    American Association of State Highway & Transportation Officials

    444 North Capitol Street, NW, Suite 225
    Washington, DC    20001

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  USA  20001
  • Project Managers:

    Harrigan, Edward

  • Performing Organizations:

    Advanced Asphalt Technologies, LLC

    108 Powers Court, Suite 100
    Sterling, VA  USA  20166-9321
  • Principal Investigators:

    Christensen, Donald

  • Start Date: 20050701
  • Actual Completion Date: 20100630
  • Source Data: RiP Project 11866

Subject/Index Terms

Filing Info

  • Accession Number: 01462919
  • Record Type: Research project
  • Source Agency: National Cooperative Highway Research Program
  • Contract Numbers: Project 9-33
  • Files: RiP, USDOT
  • Created Date: Jan 3 2013 2:12PM