BVFF nummer:
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2017:1-05
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Projekttitel
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Simple and Quick Evaluation of Unbound Materials Bearing Capacities That Could be Used as Input Data in Mechanistic-Empirical Pavement Design (ERAPAVE)- Bärighets- kontroll av obundna material med koppling till M-E- beräkningar (ERAPAVE)
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Projektledare/Kontaktperson
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Dina Kuttah
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Telefon
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013204245
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Utförarorganisation
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VTI
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Medutförare
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Projektet är förankrat hos Klas Hermelin i Trafikverket
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Bakgrund
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In thin-asphalt surfaced and unsurfaced pavements, the granular base and sub-base layers provide the bulk of the bearing capacity. For a long time, the behaviour of subgrade soils and pavement granular materials was evaluated based on a quasi-static property, such as the California Bearing Ratio (CBR). With the introduction of the concept of the resilient modulus (Mr) as the material stiffness, considerable attention has been devoted to evaluate the behaviour of subgrade soils as well as the base and sub-base granular materials under repeated dynamic loading. Unfortunately, the resilient modulus tests of unbound materials are relatively expensive and time consuming. As a result, many of the pavement design standards are based on materials properties evaluated using simpler and faster tests such as the plate loading test, static CBR, and others. In spite of the fact that these static tests are very common all over the world, but they are not correlated efficiently to the dynamic response of the pavement structure under the actual traffic loading of moving vehicles. Therefore, it has become necessary to estimate the materials properties using simple dynamic field tests and correlate the resulting materials properties and behaviors to the corresponding dynamic material properties evaluated using dynamic triaxial tests by developing empirical equations.
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Sammanfattning
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The current project deals with evaluating the stability of unbound materials used in roads construction using relatively new simple, cheap and time saving testing technic in the field. Also, the project will verify the validity of using a new testing approach to estimate the dynamic properties of unbound materials using simple technics instead of determining the dynamic properties using the complex dynamic triaxial tests. The dynamic CBR tests will be used to control the material stability in the field and to estimate the dynamic properties of unbound materials using repeated load approach.
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Förväntat resultat
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The overall tests results will be analyzed to define the relation between the material properties obtained using the dynamic triaxial tests and the corresponding materials properties obtained using the dynamic CBR test for different compaction moisture contents and compaction efforts ranges. As a result, if a strong correlation will be obtained, the outputs of the simple dynamic CBR tests can be used as an indication to the dynamic response of materials and even used in Mechanistic-Empirical Pavement Design software instead of the materials properties obtained from the dynamic triaxial tests.
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Plan för resultatspridning och implementering
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The project results will be published in an international scientific journals and/or international Conferences. In addition, the results will be presented in national workshops in Sweden.
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Tidsramar
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Project start: 2017-03-01 Project end: 2019-07-01
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