A Novel Embeddable TiO2 Potential Sensor for Corrosion Monitoring in Concrete Structures

Structural deformation of reinforced cement concrete (RCC) structures often initiated by the corrosion of reinforcement bars has been a major issue in the construction industry. The inadvertent presence of chloride ion is perceived to be the primary cause of corrosion in seashore areas, where the rate of corrosion enhanced under hot, humid and salty environment. Most of the analytical instrumentation installed for concrete corrosion studies have contact sensors which face many challenges in producing accurate and reliable results from long-term continuous monitoring. The aim of the present study is to develop a novel embeddable potential sensor using titanium dioxide (TiO2) nanoparticles with provisions for flexible spatial installation for corrosion detection in RCC structures. The sensors are developed by indigenously fabricating the electrodes and emplacing them inside concrete environment in sequence while casting. The corrosion rate is monitored in terms of potential measurements by exposing the electrodes to interact with the hydrochemistry of concrete. The results indicate that intrinsic anticorrosive resistance of the nano-based sensor is favourable for detecting early signals of chloride corrosion with good sensitivity ( ≤ ± 5 mV). The potentiodynamic results confirm the stability of the sensor under different aggressive environmental conditions. The interpretations of the ionic corrosion potential results suggest reliability of the peak signals which helps in estimating the spatial extent of corrosion migration for initiating necessary preventive measures. The proposed sensors can be effectively employed for sustainable rehabilitation operations by easy detection of environmental stresses such as moisture ingress and saline intrusion on the exposed surfaces.