Modelling the flow behavior of asphalt under simulated compaction using discrete element

• The flow differences between the particles of asphalt mixtures compacted in the laboratory and in the field have been identified as one of the reasons for the discrepancies between laboratory and field results. In previous studies, the authors developed a simplified test method, the so-called compaction flow test (CFT), for roughly simulating the flow of particles in asphalt mixtures under compacting loads under laboratory conditions. The CFT was used in different studies to examine its capability of revealing the differences between the flow behavior of different asphalt mixtures under different loading modes. The promising results encouraged further development of the CFT by investigating the impact of simplifications and boundary conditions on the results of the test. For this reason, discrete element method (DEM) was utilized and the possible impacts of the mold size as well as the shape of the loading strip on the results of the CFT were simulated for a mixture with extreme idealized aggregate structure. The results indicate that in case of wearing course layers with a single size gradation of 11mm spheres, the length of the CFT mold can be increased from 150mm to 200-250mm for reducing disturbances from walls of the mold. However, since the majority of the flow is expected to take place within the first 100-150mm length of the mold, reasonable results are obtained even without changing the size of the CFT mold. Moreover, comparing results with different loading strip geometries and loading rates indicates that the current CFT setup still appears to provide consistent results.    

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik -- Infrastrukturteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering -- Infrastructure Engineering (hsv//eng)

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