A Structural Health Monitoring Technique

The addition of carbon microfibers has proved to be one of the most effective means of improving the electrical conductivity of cementations matrix. In the present study, 5x5x5cm carbon fiber reinforced mortar specimens were positioned in a 60Hz, ± 2.5V AC circuit with a data acquisition system in order to monitor the changes in its electrical resistivity under the influence of different parameters. It was seen that a high fiber fraction and low moisture content makes the specimen act like a pure resistor with negligible capacitance or inductance associated with it. It was also observed that electronic conduction was dominant over electrolytic conduction in a mix proportion with high fiber volume fraction and low water to cement ratio. The resistivity was found to steadily decrease under compressive loading and then increase during the formation of micro and macro-cracks. This study provides an appropriate basis to monitor the health of structures by measuring the increase in electrical resistivity versus the load during the life time of the concrete structures

Keywords:

Concrete , carbon fiber , resistivity , loading rate