Damage in carbon fiber-reinforced concrete, monitored by both electrical resistance measurement and acoustic emission analysis

Real time damage detection of concrete structure is becoming more and more critical. In this paper, damage in carbon fiber-reinforced concrete (CFRC) under uniaxial compression and three-point-bending conditions was monitored by both electrical resistance measurement and acoustic emission (AE) analysis. The research showed a good correlation existing among curve of load-deflection, changes in electrical resistance and AE hits. For CFRC, the electrical conductivity depends on the percolation network formed by the contacting carbon fiber. The damage occurring inside materials causes breakdown of percolation network and results in an increase in electrical resistance. Therefore, the change in electrical resistance reflects the damage during the entire loading process. On the other hand, AE technique can detect and possibly identify damage mechanisms in fiber-rein forced composites by analyzing AE parameters. These two techniques are complementary for the monitoring damage in CFRC. (C) 2007 Elsevier Ltd. All rights reserved.