Title:
Carbon-Fiber Cement-Based Materials for Electromagnetic Shielding
Author(s):
Sivaraja Muthusamy and D. D. L. Chung
Publication:
Materials Journal
Volume:
107
Issue:
6
Appears on pages(s):
603-611
Keywords:
carbon; electrical resistivity; electromagnetic shielding; fiber; mechanical properties; silica fume; sizing
DOI:
10.14359/51664047
Date:
11/1/2010
Abstract:
Short carbon fiber is used as an admixture with silica fume to form cement-matrix composites. It is made from pitch or polyacrylonitrile (PAN). PAN-based fiber with a diameter of 7 mm is effective for providing electromagnetic interference (EMI) shielding (1 GHz), low electrical resistivity (DC), and high flexural strength and modulus. Its shielding ability is superior to that of previously studied pitch-based fiber with a diameter of 15 mm (6 × 10–4 in.). Thermally desized PAN-based fiber is less effective than the unsized counterpart for providing shielding, reflection, and low electrical resistivity, but it is more effective as a reinforcement. An increase in the fiber content increases the shielding effectiveness, decreases the resistivity; and increases the flexural strength and modulus. For each fiber content in percentage by mass of cement, the addition of sand causes a slight decrease of the shielding effectiveness; at the same fiber volume fraction, the shielding effectiveness is similar for cases with and without sand.