Electrical responses of carbon fiber reinforced cementitious composites to monotonic and cyclic loading

Abstract

In this paper, the electrical responses of carbon fiber reinforced cementitious composites (CFRCC) to both monotonic and cyclic loading were investigated by electrical resistance measurements. Damage occurring within specimens was also investigated by acoustic emission (AE). Results indicated that the conductivity of the composite was related to the stress level. Under monotonic loading, the electrical resistance decreased with increasing stress at low stress levels and increased with increasing stress at higher stress levels. Under cyclic loading, at lower loading amplitude, the electrical resistance of the system showed reversibility with the change of the load, however, when the loading amplitude was larger, it showed the irreversible increase. Both cases indicated that the breakdown and rebuild-up process of the conductive network under pressure may be responsible for the stress dependency of conductivity. The damage occurring inside material can be monitored in real time by measuring the change in electrical resistance during loading and unloading.