Mix Design of Bitumen Stabilised Materials

1
Mix Design of Bitumen Stabilised Materials

• Kim Jenkins
• TG (2) Update
• Phase 2 Research Phase
• RPF May 2008

tellenbosch
2
TG(X)
3
Project Scope
Task Description
1 2 Triaxial (Protocol New Standard)
3 4 Stiffness (Correlation Existing New)
5 6 Adv Classification (Existing New)
7 8 Curing (Lab Procedure Validation)
9,1011 Durability (Moisture Binder)
12 Compaction
4
Task 2 Simple Tri-axial

• Specimen geometry 150 mm Ø x 300 mm
• Monotonic tests (only)
• s3 0 , 50, 100, 200 kPa
• Loading rate 2 e/min
• SIMPLE (no membrane)

tellenbosch
5
Lab Survey
6
Conceptualisation
7
Find your own solutions (innovate)
8
Trials with latex membrane as confining tube
(Mulusa)
9
Final design
10
Task 7 Curing (lab protocol)
Emulsion Foam
No active Active filler filler
No active Active filler filler
11
TASK 8 CURING VALIDATION
PSPA
tellenbosch
12
Lab cure moisture versus temperature
13
Mr (lab) versus Moisture Content
14
Field moisture versus curing time
15
Mr (field) versus cure time
16
TASK 9 Durability Improved Tests- Untreated
Material Properties - Moisture sensitivity tests
(Twagira)
Moisture Induction Sensitivity Test MIST
17
MIST saturation time
Degree of saturation ()
50mm layer
Pulsing time (sec)
18
Sr versus Mr
Resilient Modulus, Mr (MPa)
Degree of Saturation ()
Resilient Modulus (MPa)
Specimen type
19
Task 12 Compaction

• Vertical impact
• Kneading effect
• Create a triaxial specimen

(Kelfkens)
20
Mounting The Vibratory Hammer

• Bosch GSH 11E

• Kango 637

21
Compaction Experiment

• Individual Layers for samples - weighed off

22
Foam vs Emulsion Compaction Time per Layer
35s
70s
0s
0s
FOAM
EMULSION
23
CT Scans
24
Temperature Influences Foamed Mix
25
Materials Classification BSMs- Similar to
granular
BSM1
BSM2
BSM3
BSM1
BSM2
BSM3
26
Summary

• Appropriate testing is needed i.e. shear
  parameters for BSMs
• Stiffness is a key mix property
• Curing protocol being refined
• Classification system should be robust
• Aiming for mid 2008 for completion

27
Get the mix right and laying will be the easy
part
28
But be careful
29
Questions?