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DY: Fachverband Dynamik und Statistische Physik
DY 19: Franco-German Session on Granular Matter I
DY 19.10: Vortrag
Dienstag, 10. März 2026, 12:15–12:30, HÜL/S186
CT-resolved flow-induced particle migration in pipe bends during concrete pumping — •Daniil Mikhalev1, Moritz Kluwe2, Rüdiger Schwarze2, and Viktor Mechtcherine1 — 1TU Dresden, Institute of Construction Materials, 01187 Dresden — 2TU Bergakademie Freiberg, Institute for Mechanics and Fluid Dynamics, 09599 Freiberg
In this study, we investigate how the granular microstructure of pumped fresh concrete evolves as the suspension passes through a 90∘ pipe bend. The material is pumped under realistic operating conditions and allowed to harden in situ. To identify shear-dominated regions, a dyed low-viscosity premix is introduced as a passive tracer. Hardened bend sections are then analysed using high-resolution X-ray computed tomography. Segmentation of individual grains, voids, and tracer regions enables spatial statistics of solid volume fraction, grain-size distributions, air-void patterns, and shear-zone geometry along the inflow-bend-outflow transition.
Preliminary results reveal measurable deviations from the symmetric plug - lubrication-layer structure known from straight pipe flow, including radial and azimuthal segregation and restructuring of both solid and air phases. The combined tracer-based and tomographic approach provides a foundation for linking experimentally resolved microstructure with continuum suspension models and particle-migration theories in complex geometries.