HMA Mix Design Process

Progress Report

Activities

• HMA User Guide Available at month end

• Need to consider roll-out• Mix Design Activities– Forensic Studies contemplated– APT – considering some testing• HVS• MMLS

– Sabita – Research Needs

HMA Users Guide

• Highlight important issues and content given in the IGHMA;

• Caution the reader against certain pitfalls or gaps in the IGHMA;

• Provide some guidance on supplementary procedures to achieve a sound and workable mix design; and

• Provide comment and guidance on issues that have arisen since the IGHMA was launched in 2001.

Chapters (1)

• Chapter 1 - Introduction• 1.1 General issues related HMA design• Chapter 2 – Mix Design Procedures• Phase 1: Evaluate Design Situation and

Identify Objectives• Phase 2: Mix Type Selection• Phase 3: Component Selection• Phase 4: Volumetric Mix Design• Phase 5: Performance testing

Chapters (2)

• Chapter 3 - Discussions on different mix types and specific design considerations

• Sand-Skeleton mixes• Stone mastic asphalt• Open-graded mixes• Large aggregate mixes for bases

(LAMBS)• Semi open-graded mixes

Chapters (3)

• Chapter 4 – Design Implementation: Construction and Quality Assurance aspects

• Segregation• Compaction and layer thickness• Temperature control• Binder variation• Joints• Trial sections• Sampling and testing• Statistical judgement plans

Conclusions

• User Guide Available Soon

• Highlights problems and identifies areas for research and investigations

• Will need supplementary work to actually improve criteria and procedures