Dispersion of carbon fibers and conductivity of carbon-fiber-reinforced cement-based composites

With the aids of ultrasonic wave and a new dispersant hydroxyethyl cellulose (HEC), carbon fibers were uniformly distributed in a cement matrix and homogenized carbon fiber reinforced cement composite (CFRC) was prepared. The fracture surface of the hardened samples was observed by scanning electron micros-copy (SEM). The influence of the lengths and contents of carbon fibers as well as the water/cement weight ratio on the conductivity of the composite was investigated. Results show that the electrical resistivity tended to decrease with the increasing of carbon fiber contents. It increased first and decreased then with the increase of water/cement ratio. By the vibrating and pressing method, the resistivity reduced far greatly than that by the vibrating method.