metoda austroads 2011_updated.ppt

8/11/2019 metoda austroads 2011_updated.ppt

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Design of Flexible Pavement(Guide to Pavement Technology Part 2:Pavement

Structural Design Austroads)

First Published 2008, Updated : Feb 2010

a.k.a NAASRA (National Association of

Australian State Road Authorities), 1979


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Overview Austroads is the association of State, Territory, and

Federal Road and traffic authorities in Australia. It

was established in 1989 to replace NAASRA (National

Association of Australian State Road Authorities)

Austroads published A Guide to the Structural Design

of Road Pavement in 1992, renewed May 2008, last

updated Feb 2010)

This Guide based on Analytical Approach in

Pavement Design


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Guide to Pavement Technology

by Austroads


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Pavement Design System by Austroads

(Chapter Framework)


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Project Reliability (Chapter 2)


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Environment Moisture Environment

The stiffness/strength of unbound materials and subgrades isheavily dependent on the moisture content of the materials.

The moisture condition in unbound granular pavement materials

can also have a major effect on performance. When the degree ofsaturation of unbound granular materials exceeds about 70% thematerial can experience significant loss of strength/stiffness

Temperature Environment

For pavement design, the temperature of asphalt can becharacterized in terms of the Weighted Mean Annual PavementTemperature (WMAPT). The WMAPT takes into account therelationship between asphalt temperature and fatigue life ofthick asphalt pavement, published by SHELL in 1978. Calculationof WMAPT can be seen in Appendix B.


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Procedure to calculate WMAPT


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Sample WMAPT in Australia Region


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Subgrade Evaluation


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Presumptive value of CBR


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Subgrade Strain Criterion


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Flexible Pavement Material

Unbound Granular Material

Modified Granular Materials

Cemented Material

Asphalt


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Pavement Material Category


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Unbound Granular Material

Consist of gravelor crushed rockswhich

have a grading that makes them

mechanically stable Characterization : Modulus Elastic and

Poisson ratio (assumed : 0.35)

Properties : Cross Anisotropic

Presumptive value : Table 6.3


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Presumptive Value of Elastic

Parameter of Unbound Granular


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Modified Granular Material


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Cemented Material


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Presumptive Values


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Fatigue Criteria


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Asphalt

Combination of bitumen and aggregates

which are mixed together, spread, and

compacted while hot to form pavement layer Characterization : Modulus Elastic and

Poisson ratio, can be determined by

Laboratory (UMATTA) or nomograph (Figure

6.7)

Properties : Isotropic


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Modulus of Asphalt (Australian

Typical)


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Fatigue Criteria


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Design Traffic


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Design New Flexible Pavement

There are two option :

Mechanistic Procedure

Using CHARTS, see the catalogue in Table 8.4 3 Layers

Granular Base (EC01 to EC03)

Cemented Base (EC07 to EC18)

2 Layers Full Depth Asphalt (EC04 to EC06)

4 Layers (EC19 to EC24)


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Pavement Structure Model

Model of Pavement Loading

-Dual Wheel

-Uniform Circular Loading

-Spacing 330mm center to center


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Two Layers (Full Depth Asphalt)


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Three Layer (Unbound Granular

Based)


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Three Layers (Cemented Base)


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Four Layers


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Mechanistic Procedure


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CIRCLY Output


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CIRCLY Output


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CIRCLY Output

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metoda austroads 2011_updated.ppt