Effect of ultra-fine fly ash on the dielectric behavior of CFSC under stress

Abstract

Small size particle of ultra-fine fly ash was contributed to the dispersion of carbon fiber in composite in the preparation process. The dispersibility of carbon fiber in composite was associated with self-sensing property of composite. The effect of ultra-fine fly ash on the change in relative dielectric constant of carbon fiber sulphoaluminate cement composite under stress was investigated. The sensitivity, accuracy and reversibility of the change in relative dielectric constant under stress have been improved when 10% content (by mass of cement) of ultra-fine fly ash was added into carbon fiber sulphoaluminate cement composite (CFSC). Besides promoting micro capacitor creation, ultra-fine fly ash could endow CFSC with excellent mechanical property and weaken the ions polarization effect. The combination of above three effects upgraded the dielectric behavior of CFSC under stress. © 2011 VBRI press.