Experimental Investigation of Self-Sensing Carbon Fiber Reinforced Cementitious Composite for Strain Measurement of an RC Portal Frame

Traditional structural monitoring systems have disadvantages such as the shorter life span of sensors relative to that of the structure being monitored. The present study uses carbon fiber reinforced cementitious composite (CFRC) as a structural monitoring sensor to extend the life of a sensor to match that of the structure. There are some known advantages of CFRC, such as high tensile strength and high ductility that increase the seismic capacity and security of such structures. However, CFRC has functionality similar to piezoresistive materials, which can be used as self-sensing materials for strain measurement and damage detection. This property is based on the reversible effect of strain on the volume of electrical resistivity and the irreversible effect of material damage on its resistivity. Considering the economic benefits, the fiber content is only 0.2 vol.%, which is less than half of the amount used in other studies. The experimental results show that the conductivity of current materials is significantly improved by CFRC and that it can be used for strain measurement and damage detection. Moreover, the experimental results of CFRC-coated beams and the RC portal frame can be kept in a database for applications in structural health monitoring.