- 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