1. Bituminous Stabilized Materials Guideline: Inception Study Project Funded By: Gautrans Sabita

2. Background ETB Materials; Two guidelines exist:  Sabita Manual 14 (1993)  Sabita Manual 21 (1999) Foamed Bitumen Materials:  TG2 Interim Guideline Guidelines widely used, but there is a need to: Modernize Improve Create a single, combined guideline

3. Main Deficiencies: Mix Design Lack of a suitable Curing Method More appropriate tests to assess:  Flexibility  Shear Strength  Durability

4. Main Deficiencies: Structural Design Conservative structural designs (catalogue and design charts) Questions about 2-Phase modelling Need to incorporate curing effects Limited database used for development Lack of validation using long term field data

5. Refinement and Guideline Compilation Project Structure Phase 2: Mix Selection Criteria Phase 3: Mix Design Issues Phase 4: Structural Design Issues Phase 5: Construction Issues Phase 5: Guideline Finalization Mix Design (K Jenkins) Structural Design (F Long) Phase 1: Inception Study

6. Inception Study Objectives: Mix Design Identify Durability Test and gather curing data Investigate Triaxial Testing protocols Investigate Strain-at-Break Plan and re-direct further activities

7. Inception Study Objectives: Structural Design Gather available performance data (LTPP & HVS) Analyze and identify trends (if any!) Assess key deficiencies in available information Plan and re-direct further activities

8. Progress to Date: Structural Design 126 Roads appeared on radar 104 Emulsion Treated Base 22 Foamed Bitumen Only some roads suitable to study  Duplication amongst reported projects  Many roads recently constructed  Some very low traffic and/or no data  Urban legend

9. Some Best Candidate Projects N12-19 (1974) N2-16 (1982) N3-4 (1988) N4-5X (1997) N4-1 (1997) MR27 (1988) N1-1 (1984) N1-13 & 14 (1980) P504 (1995) Same-Himo Project (1992, LTPP study) N7-7 (1987) P24-1 (1999) ± 20 Promising projects in total HVS Tests: N3-4, Mooi River N2-16, East London P9-3 Petrus Steyn P243-1 Vereeniging N7, near CT N12-19 (current)

10. Classification Approach ETB/Foam source material ETB/Foam stability & flexibility properties Support Layer quality and class Subgrade quality and class Maximum deflection range before/after construction Standard axle range accommodated in field or HVS Develop a design approach that relies on measurable, non-ambiguous parameters Ensure transparent, straightforward validation of recommended designs For each project, assess and classify: Vision: