Paper number 831

ORIENTATION PROCESS DURING EXTRUSION OF REACTIVE POWDER CONCRETE REINFORCED WITH SHORT METAL FIBERS

Arnaud POITOU¹, Francisco CHINESTA², Gérard BERNIER¹

1LMT ENS de Cachan, 61 avenue du président WILSON
94235 CACHAN CEDEX - FRANCE
2Laboratoire des matériaux macromoléculaires, CNAM,292 rue Saint Martin
75003 PARIS - FRANCE

Summary

This paper addresses the problem of orienting short metal fibers (1cm length, aspect ratio 50) in a reactive powder concrete during an extrusion process dedicated to manufacture reinforced tubes. It is shown that in choosing an appropriate geometry for the die it is possible to orient the fibers in an ortho-radial direction which is the most efficient if one whishes to reinforce the tube mechanical properties for an internal pressure loading. This result is obtained with both a theoretical and an experimental approach. In a theoretical framework we carried out a numerical modeling with a constitutive behavior deduced from the anisotropic suspensions theory. This calculus anabled us to imagine the shape of the die. Tubes are then extruded and the fibers orientation is measured through optical microscopy.

Keywords

reactive powder concrete, short fibers, extrusion, numerical modelling, experiments, orientation prediction.