Electrical characterization of smart sensory system using carbon based textile reinforced concrete for leakage detection

The study investigates the electrical mechanism of hybrid carbon-based textile-reinforced concrete (TRC) elements with self-sensing capabilities to detect infiltration of water within cracked zones. The concept is based on carbon rovings that simultaneously serve as the reinforcement system as well as the sensory agent. The main goal of the study is to characterize the mechanism of the electrical signal obtained by exposure carbon rovings to wetting events. To meet this goal, the study uses alternating current circuits, which yield, additionally to the resistance or voltage changes, the characterization of the capacitance and inductance of the system. Two sensing concepts are investigated. Both concepts take advantage of the continuous configuration of the carbon rovings, which enables direct connection of the roving ends to the data acquisition system. The first sensing concept assumes that the electrical properties of a single carbon roving is affected by wetting, while the second assumes that wetting the interface between two adjacent carbon rovings links them electrically. The experimental investigation is performed on bare carbon rovings, and on a cracked carbon based TRC beam. Test results characterize the electrical mechanism of the wetting events and reveal its potential use as a basis for smart textile-reinforced systems with integrated monitoring functions.