Carbon-fiber-reinforced cement-based sensors

The addition of carbon fibers has proved to be one of the most effective ways of improving the electrical conductivity of ordinary cement pastes. This implies that such materials can be used in strain, temperature, and chemical sensing. The present study was aimed at the development of such sensors. Inexpensive, petroleum-pitch-based, mesophase, high-modulus carbon fibers were used throughout. It was seen that materials with high conductivity could be obtained by reinforcing hydrated cement paste with carbon fibers. Electronic conduction was seen as the dominant mode over electrolytic conduction. Compared with strain, the influence of temperature on the electrical resistivity was found to be insignificant, implying a lack of need for temperature correction. Results also indicate that these sensors can be excellent crack detectors.