Cover of Determining the Foaming Characteristics of Bitumen
Determining the Foaming Characteristics of Bitumen
  • Publication no: AGPT-T301-17
  • Published: 24 October 2017

Foaming of bitumen permits the bitumen to be evenly distributed throughout a soil or a granular material. It is critical for the bitumen to remain as viable foam for a period to enable it to be successfully blended into the host material.

The foaming characteristics of bitumen are defined by the expansion ratio and half-life of the bituminous foam. The bituminous foam is produced by introducing a small amount of water into hot bitumen.

The aim is to determine the percentage of water and foaming agent (if necessary) to produce the best foam characteristics for a particular bitumen. The amount of water will be a compromise between having as high as possible an expansion ratio with the longest half-life.

This method is an adaptation of the method described in Wirtgen Cold Recycling Technology.

  • 1. Scope
  • 2. References
  • 3. Definitions
  • 4. Equipment
  • 5. Calibration and Validation
  • 6. Procedure
    • 6.1. Using a Dipstick
    • 6.2. Using a Calibrated Ruler
  • 7. Calculation
    • 7.1. Expansion Ratio using Calibrated Dipstick
    • 7.2. Expansion Ratio using a Calibrated Ruler
  • 8. Reporting
  • Appendix 1 Calibration of a Dipstick