Repeated Load Triaxial Testing

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Repeated Load Triaxial Testing Pavement
Rutting design to avoid
Testing to understand Materials is key to success
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Rutting shear in subgrade
Austroads Pavement Design Guide ensures adequate
cover/protection to subgrade
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Rutting shear in base
Rutting compaction in base
Specifications usually ensure aggregates do not
fail (but not always! Especially if they get wet)
A Repeated Load Triaxial Test (applies 350,000
load cycles)- Will determine the amount of
rutting in the aggregate (wet and dry) - To
determine suitability of chosen materials
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Repeated Load Triaxial Testing
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Repeated Load Triaxial Testing
Compaction to target density
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Repeated Load Triaxial Testing
Soaking sample For saturated test
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RLTT - Dry
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RLTT - Wet
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Need to get above 15 Million ESA
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Not saturated all the time but would like at
least 1 Million ESA
Most M4 Aggs not ok when wet
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Most stabilised aggregate options very good when
dry (same as 10 11)
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Most stabilised aggregate options very good when
dry (over 50 MESA)
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Pavement Design Rut Depth Models RLTT on
subgrade, subbase, basecourse
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Pavement Design Rut Depth Models RLTT on
subgrade, subbase, basecourse
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Pavement Design Rut Depth Models RLTT on
subgrade, subbase, basecourse
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Pavement Design Rut Depth Models
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Pavement Design Rut Depth Models
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Pavement Design Rut Depth Models
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Flexural Beam Testing other tests to check risk
of cracking
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Flexural Beam Testing
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Flexural Beam Testing
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Flexural Beam Testing
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Flexural Beam Testing Breakage Test
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Flexural Beam Testing Fatigue Test
CAPTIF 4 - Modulus 1400MPa to 2000MPa
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Summary

• Aim to provide a pavement by Repeat Load Triaxial
  testing that
• Is economical
• Improved performance/less risk (or eliminate
  risk) of failure/rutting when wet
• Utilises local materials and uses overburden low
  cost materials
• Flexural beam tests to design against cracking

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PaveSpec Ltd (NZ) Dr Greg Arnold - Pavement
Specialist BENG (HONS), MTECH (PAVEMENTS), PHD
(UNIV OF NOTTINGHAM, UK)
Laboratory Office location c/- Stevenson
Laboratory Ltd Cnr Fitzgerald and Quarry
Rds RD2 Drury 2578 South Auckland, New Zealand
Phone [phone] Mobile [phone] Fax
09 984 8599 Email greg.arnold_at_pavespec.co.nz PO
Box 570 Drury 2247 New Zealand
www.RepeatedLoadTriaxial.com Proof testing
materials and design to achieve maximum pavement
performance at minimum cost