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PavementPavement design in design in SwedenSweden

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Tomas WinnerholtTomas Winnerholt M.Sc. Civ.Eng.

Road Engineering Section, Society and Traffic

Road Maintenance, Pavement Design and

Bridge Weigh-In-Motion

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Swedish design manualSwedish design manual ATB ROAD 2005ATB ROAD 2005

• Is a general technical specification which shall be used within SRA´s field of activities for road projects.

• The technical service life of the pavement, at least, 20-40 years, New construction.

• Technical service life for a maintenance measure is to be choosen in every case.

• Can be used in both general contracts and turnkey contracts with functional demands.

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Swedish design manualSwedish design manual ATB ROAD 2005ATB ROAD 2005

• SRA is currently revising the whole structure of the design manuals (roads, bridges, tunnels)

• New structure is coming, probably in early 2008 (for roads at least)

• There are some revisions of the design manual content planned

• New ”user manual” for road maintenance and road strengthening is under development.

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Design parametersDesign parameters• Accumulated traffic load, calculation of the

equivalent number of standard axles on basis of the traffic-forecast during the intentended technical service life. The equivalant number must be less than the allowable.

• Pavements shall be designed for the applicable climatic zone and climatic periods.

• Design, taking frost heave into account.

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StandardStandard AxleAxle

300 mm800 kPa

100 kN

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The The modelmodel• Stresses and strains are calculated using a

linear elastic material model.• Materials are considered homogenous with

isotropic properties.• The dead-weights are neglected.• Applied load is considered to be static

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Largest allowablevertical compression strain

Largest allowablehorizontal tensile strain

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The The modelmodel -- strenghtsstrenghts+ Economically acceptable road structures in

the whole country.+ Validated against cracking on real

pavements, reasonable results+ Built on a proven technique+ Frost design using real measured

temperatures

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The The modelmodel -- weaknessesweaknesses- Only fatigue- Does not consider rutting- In principle only standard bitumen bound

materials- The values for stiffness moduli is adopted for

the model (no realistic values)

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Design Design tooltool –– PMS ObjektPMS Objekt

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Design Design tooltool

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Design Design tooltool

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Design Design tooltool

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Design Design tooltool

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Design Design tooltool

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Design Design tooltool

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AvailableAvailable at at www.vv.sewww.vv.se

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ExperincesExperinces so far ...so far ...• The approach has been accepted.• The number of alternative solutions has

not been significantly greater than before.• The use of ”polymer modified asphalt

layers” solutions has increased.• More work for the regional directorates in

evaluation the tenders.

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What’sWhat’s nextnext on the agenda?on the agenda?• R&D efforts are beeing made in to develop

the existing model:– New concrete pavement model– Water-flow-model– Crieteria for unbound materials– Geosynthetical reinforcement

• FEM-model, Total model (in the long run)

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ThankThank you!you!