Electrode design, measuring method and data acquisition system of carbon fiber cement paste piezoresistive sensors

Carbon fiber cement paste piezoresistive sensors (CFCPS) are made of piezoresistivity of carbon fiber cement paste and mainly used for local monitoring of concrete structures. Two electrode fixing styles for measuring the resistance of CFCPS are compared and the conception of embedded gauze electrode is put forward. The characteristics, layout styles and configuration parameters of embedded gauze electrode and the methods for measuring the resistance of CFCPS are studied. The mould of sensors is designed and the data acquisition system based on voltage signal is developed. It is revealed that the four-pole layout is suitable for setting embedded gauze electrode and the direct-current four-pole method adapts to measure the resistance of CFCPS. The resistivity of CFCPS is independent of the area of voltage pole and the mesh size of gauze electrode. The space between current pole and voltage pole does not influence the resistivity of CFCPS when more than a critical value. The developed data acquisition system has many advantages such as simple circuit, good practicability, high precision and ability to realize real-time, on-line and multi-channel acquisition.