Characterizing fiber dispersion in cement composites using AC-Impedance Spectroscopy

A novel method is developed to evaluate fiber dispersion issues in short (or discontinuous) fiber-reinforced cement composites. Fiber orientation, global segregation (i.e., as a result of gravitational settling or improper mixing), and local aggregation (i.e., small fiber agglomerates distributed uniformly throughout the matrix) are quantified using an electrical measurement technique. The method is based on AC-Impedance Spectroscopy (AC-IS) and uses the intrinsic conductivity approach to characterize fiber dispersion through a process that is able to isolate some of the effects. A flow chart is developed to describe the method, which consists of 3D AC-IS measurements, a point probe technique, and a dispersion factor (DF) analysis. (c) 2004 Elsevier Ltd. All rights reserved.