Title:
Viscoplastic Analysis of Cementitious Extrudates under Squeeze Flow
Author(s):
C. K. Chau, Xiangyu Li, and Zongjin Li
Publication:
Materials Journal
Volume:
106
Issue:
6
Appears on pages(s):
493-502
Keywords:
cementitious composite; extrusion; paste; squeeze flow; viscoplasticity
DOI:
10.14359/51663331
Date:
11/1/2009
Abstract:
A successful extrusion of fiber-reinforced cementitious composites requires a thorough understanding and proper design of the rheological properties of extrudates. The squeeze flow test is regarded as an effective method to evaluate the rheological properties of semi-solid-state fresh extrudates. Based on the strain rates derived from a generalized velocity field, the viscoplastic behavior of cementitious extrudates can be analyzed using the von Mises yield criterion combined with the nonlinear Herschel-Bulkley constitutive relationship. As far as the squeezing force is concerned, the theoretical predictions show good agreement with the experimental measurements. It is found that the bulging phenomenon of a specimen during the squeeze flow process can be depicted by the radial velocity component. Moreover, the velocity field of fresh cementitious extrudates under large plastic deformation is obtained. The present viscoplastic analysis of short fiber-reinforced cementitious extrudates under plastic flow is believed to be a promising mathematical tool toward optimization of formulation for the booming extrusion application.