Preparation of cement modified by multi-walled carbon nanotubes and investigation of its piezoelectric property

Abstract

This study focuses on investigating the properties of a cement-based piezoelectric composite modified with 0.5 % Multi-Walled Carbon Nanotubes (MWCNTs) under varying stress conditions. Through calibration methods, a critical point named G was identified at around 60.4 MPa. Below this point, the force-electric response displayed a linear relationship, characterized by an average sensitivity of 117 pC/N. Conversely, above this point, non-linear behavior surfaced due to internal damage within the piezoelectric ceramic, leading to diminished piezoelectric properties. The frequency response characteristics highlighted efficient conversion of pressure signals to electrical signals with minimal delay, showcasing stability across diverse cyclic loading amplitudes. In addition, a dynamic compression experiment revealed sensitivity to strain rate and the notable contribution of domain switching to total strain. Moreover, an analysis of the stress–strain curve under impact load provided insights into the composite's non-linear growth and its response to strain rate variations.

Keywords

• Piezoelectric composite
• Multi-walled carbon nanotubes (MWCNTs)
• Strain-rate sensitivity
• Cyclic loading
• Domain switching