NOC Hi Lab Video
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June 2014 Pavement design and construction technique using high strength stone interlocked cemented aggregate low fines matrix. Gerhard van Blerk
Transcript of NOC Hi Lab Video
June 2014
Pavement design and construction technique using high strength stone interlocked cemented aggregate low fines matrix.
Gerhard van Blerk
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Introduction:“More for Less”
• Global financial constraints and a steep increase in bitumen prices
• RCA’s are seeking alternative construction techniques (Hi-Lab)
• Embrace the origin of road construction (John Loudon McAdam, 1820) through modern pavement construction techniques
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Macadam Pavement Design: “Back to Basics”
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Design Intent:High degree of aggregate interlock
Maximize stone packing, forcing “full” stone on stone interlock through a controlled process of:
• grading (percentage of large aggregate fraction)
• aggregate quality (crushing resistance)• small amount of cement (3%)• construction technique
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Material Selection and Properties: Aggregate Grading
0
10
20
30
40
50
60
70
80
90
100
Hi-Lab40 AP40 RCC
0.075 1.18 4.75 9.50 19.0 37.5 63.0
SIEVE SIZE (mm)
% P
ASSI
NG
Hi-Lab40 vs AP40 vs RCC Grading Envelope
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Hi-Lab Construction Technique: Aggregate Placing
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Hi-Lab Construction Technique: Placing and Grading
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Hi-Lab Construction Technique: Cement Spreading
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Hi-Lab Construction Technique: Subbase Stabilization (mixing process)
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Hi-Lab Construction Technique: Base Stabilization (mixing process)
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Material Selection and Properties: Aggregate Grading
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Hi-Lab Construction Technique: Compaction and Final Surface
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Hi-Lab Construction Technique: Compaction and Final Surface
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Hi-Lab Construction Technique: Engineering Properties (Strength)
• Indirect Tensile Strength (ITS)
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Hi-Lab Construction Technique: Engineering Properties (Strength)
• Beam Fatigue Tensile Strain
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Hi-Lab Construction Technique: Engineering Properties (Strength)
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Hi-Lab Construction Technique: Engineering Properties (Strength)
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Hi-Lab Construction Technique: Engineering Properties (Strength)
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Hi-Lab Construction Technique: Observed Performance
Benkelman Beam Deflections
0
0.25
0.5
0.75
1
1.25
1.5
1.75
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Tatuanui(SectionA)
Tatuanui(SectionB)
Tatuanui(SectionC)
Te Rapa(Section A)
Te Rapa(Section B)
Taupiri Orini
Project Name
Ymax
(Ave
rage
Val
ue)
Selected Sand Layer Hi-Lab65 (Subbase Layer) Hi-Lab40 (Base Layer)
Back-calculated Stiffness (MPa)
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1000
2000
3000
4000
5000
6000
Selected Sand Layer Hi-Lab65 (Subbase Layer) Hi-Lab40 (Base Layer) Selected Sand Layer Hi-Lab65 + Hi-Lab40 (LayersCombined)
Project Name
Med
ian
Stiff
ness
(MPa
)
Tatuanui Te Rapa Orini
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Case Studies: Cost Saving
• Substantial cost savings without sacrificing performance.
• Pavement construction cost savings between 30% to 40%.
• Base layer construction cost savings between 100% to 400% e.g. SAC ($100/m^2) – Hi-Lab ($25/m^2).
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Conclusion/Summary:
• Realizing the proven performance associated with the Macadam design theory through modern stabilization equipment.
• Observed engineering properties are very promising.
• Case studies shows this technique to be a viable alternative to more costly options.
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