Jämförelse mellan Los Angeles-värde och nedbrytning från hjullast

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Since 2004 the Swedish Road Administration has had requirements on unbound base layer concerning the resistance to fragmentation, the Los Angeles value. To study how degradation from traffic load is affected by resistance to fragmentation five materials with different Los Angeles values were tested in VTI’s Heavy Vehicle Simulator (HVS).

The degradation from the wheel load has been recorded by comparing the grain size distribution before and after the HVS test. Some values from the grain size distribution have been used or calculated to easier compare the grading curves with the Los Angeles value, e.g. content of fines (material < 0.063 mm) or the area under the grain size distribution curve.

There is a clear degradation from the wheel load of the HVS in unbound base layer materials. There is, however, not a clear connection between this degradation and the resistance to fragmentation, Los Angeles value. Therefore it is not possible from this investigation to recommend a new level or category of requirements concerning the resistance to fragmentation on unbound base layer material.

The most important conclusion is that the method that has been used in this project is working to study the degradation and particle relocation in unbound layers.

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Apr

Cost Benefit Analysis (CBA) workshop in Stockholm

An open seminar and workshop in Stockholm will be held on 25-26 April 2018. The workshop deals with the use of CBA as a basis for decision-making in the public sector. The workshop is organized by, among others, Professor Jan-Eric Nilsson, VTI.

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