Fabrication and characterisation of 0–3 KNLNTS piezoelectric ceramic/alite calcium sulfoaluminate cement composites

Abstract

The objective of this study was to fabricate and investigate new smart composites as sensors and actuators in civil engineering for structural health monitoring. A novel 0–3 piezoelectric composite consisting of (K0.44Na0.52Li0.04) (Nb0.84Ta0.10Sb0.06)O3 (KNLNTS) as the piezoelectric phase and alite calcium sulfoaluminate (ACSA) cement as the matrix phase is presented. Because these are new types of materials, the processes to synthesis each material have been intensively investigated. The ACSA cement was successfully prepared using an appropriate composition and fired at 1250 °C for 30 min. The Rietveld refinement technique was used to determine the amount of each quantitative phase calculated from the X-ray diffraction patterns of the model structure. The phase formation, microstructure evolution, and dielectric and piezoelectric properties of the KNLNTS ceramics fired at various temperatures were investigated. The optimum synthesis conditions yielded sintered KNLNTS ceramics with a dielectric constant and piezoelectric coefficient of 1386 and 118 pC/N, respectively, at room temperature. The KNLNTS/ACSA cement composites were prepared with various KNLNTS contents in the range of 30–70 vol.%. Furthermore, the hardened density, acoustic impedance, microstructure, dielectric properties, and piezoelectric coefficients of the composites were investigated. The KNLNTS/ACSA cement composite can potentially be applied as a sensor for monitoring external parameters such as stress, strain, and cracks in concrete structures, based on the piezoelectric effect.

Keywords

• Alite calcium sulfoaluminate cement
• KNLNTS ceramics
• Composite
• Dielectric properties
• Piezoelectric coefficient