Bituminous Stabilized Materials Guideline Project Initiated By: Gautrans Sabita.
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Transcript of Bituminous Stabilized Materials Guideline Project Initiated By: Gautrans Sabita.
Bituminous Stabilized Materials Guideline
Project Initiated By:
Gautrans
Sabita
The Need for Recycling Alternatives
Percentage of Designs in TRH4 Catalogue for > 3 msa
10% 20% 30% 40% 40% 50% 60%
G1 base on cemented subbase
> 100 mm Asphalt on cemented
subbase
> 400 mm Cemented Base
G1 or G2 base on unbound subbase
300 to 350 mm Cemented base &
subbase
Current Guidelines: Main Deficiencies
Mix Design Lack of a suitable curing method Lack of a suitable Shear Strength test Lack of criteria to assess durability & flexibility
Structural Design Very Conservative designs Need to expand knowledge base and incorporate
long term field data
Project Structure
Mix Design Structural DesignPhase 1: Inception Study
Mix DesignStructural
Design
Phase 2: Development of Methodologies
Phase 3: Guideline
Compilation & Review
Selection Criteria
Mix Design Guidelines
Structural Design Issues
Construction Issues
Guideline Finalization & Review
Tasks for Phase 2• Mix Design
– Adapt triaxial test and classification limits– Develop durability test and classification limits– Standardize specimen preparation, curing,
compaction & testing
• Structural Design– Expand LTPP database– Develop and calibrate material classification
method and pavement design method
Crushed stone
CTB
Natural gravel
ETB
Support
3 6 9 12 15 18 21 24Section Age
YearsMESA Accommodated to Date
N12-19 (1)
N12-19 (2)
N1-13&14
N2-16
30
30
25
25
N1-1 20
N3-4 17
19N7-7
P23/1 13
D2388 8
N4-5X (20-25) 8
8N4-5X (27-30)
N4/1 6
MR27 17
MR 504 (1)
P24/1
MR 504 (2)
MR 504 (3)
Same-Himo (1)
Same-Himo (2)
Same-Himo (3)
10
6
10
10
11
11
11
LTPP
3 6 9 12 15 18 21 24Section MESA Accommodated Age
Years3 6 9 12 15 18 21 2490 Surfacing200 ETB150 Lime stabilized base150 Lime stabilized base
N3 HVS (1) 0
N3 HVS (2) 0
N3 HVS (3) 0
N3 HVS (5) 0
N2-16 (322A2) 8
P9/3 (372A3) 0
P9/3 (373A3) 0
P9/3 (374A3A) 0
P9/3 (374A3B) 0
P9/3 (375A3) 0
P9/3 (376A3) 0
D2388 (397A4) 0
D2388 (403A4) 1
D2388 (407A4) 2
D2388 (408A4) 3
P243/1 (409A4) 0
P243/1 (410A4) 0
P243/1 (411A4) 1
N7 (415A5) 0
P243/1 (412A4) 1
N7 (416A5) 0
N12-19 (415A5) 30
Crushed stone
CTB
Natural gravel
LTB
Support
HVS
Structural Design MethodVision:
• Depend on Rational Inputs: Determined from field tests using a specific
procedure Direct linkage with specifications
• Clarity and Transparency Traceable validation Implements design fundamentals
• Straightforward Implementation Requires no specialist software Reliable and Robust
Design Outputs & Expectations
Cost, Effort & Experience Needed
Design Method Outputs
Reliability: E.g.:Is this design suitable for traffic of 3 to 8 mesa?
Life Cycle: How will the pavement fail? How can it be rehabilitated?
Sensitivity: What layers/parameters are most critical to prevent premature failure?
Optimization: What can be done to minimize costs at reasonable risk?
Prediction: How will rut depth, riding quality etc develop over time? Requires simulation
Development Approach
CBR 7-15%
> 200 mm G6
130 mm C4
200 mm BSM 1
Shear Potential
Range of Traffic Accommodated
Rut situation, RQ situation
Cracking situation
Need for rehabilitation
Area = Shear Potential “Fingerprint”
System Performance Indicators
System Behaviour Indicator ???
Cu
mu
lativ
e T
raffi
c Failed Condition
Good Condition
Warning Condition
Design Catalogue Structures
“Fingerprint” Indicator
Conclusion• Structural Design:
– Concept finalized March 2007– Pilot implementation & refinement Mar ’07 to
Jan ‘08
• Mix Design Protocols (2007)– Focus on Shear & Durability– Improved criteria and classification limits – Longer term testing and implementation of new
tests…(2008+)
Design Methodology ConceptTraffic Accommodated (mesa)
1
3
10
30
100 - 200 mm BSM on G7+
support
200 - 300 mm BSM on G6+
150 - 200 mm BSM on 150 mm
Stabilized Support
150 - 200 mm BSM on >250 mm
Stabilized Support