Piezodielectric Effect of Carbon Fiber—Sulfoaluminate Cement Composites

Abstract

Carbon fiber—sulfoaluminate cement composites (CFSC) were fabricated by compressing technology. The mechanism of piezodielectric effect of CFSC was discussed. The results show that the relative dielectric constant of CFSC sample decreases when the stress is less than 5 MPa. However, when the stress is in the range of 5—60 MPa, the relative dielectric constant increases linearly. When the stress exceeds 60 MPa, the relative dielectric constant drops dramatically because of the destruction of CFSC under stress. When the content of carbon fiber is 0.5% (by mass), its fractional change of relative dielectric constant corresponds to the cyclic compressive stress even if the cyclic time arrives at thousand and the stress amplitude is enhanced to 40 MPa. CFSC containing 0.5% carbon fiber content has good piezodielectric effect, which is suitable for the application of important buildings such as bridges, dams, and so on to realize real-time, dynamic, and health monitoring.