Microscale miniaturisation of chloride ion detection sensors for long term embedding in reinforced concrete structures

Abstract

Chloride ions are a potential cause of rebar corrosion in a reinforced concrete (RC) structure. Corrosion causes the rebar to expand, thereby stressing the concrete and causing the structure to deteriorate in time. An embedded chloride ion sensory system would enable real-time detection of chloride ions in the pore solution which enables timely corrective action to be taken to save the structure. Ideally, such a sensory system would be a miniature, low-cost and durable integrated circuit (IC)-sized device. This would enable widespread deployment of such a system inside many of the RC structures being built around the world. This literature review paper endeavours to look at currently existing technology in a bid to identify technology areas which can be developed through future research to design an operational IC-sized chloride ion detection system. Such a review is highly innovative as such sensors have not yet been miniaturised to the microscale IC level. The paper also uses a specifically developed parametric score system through which the best technology for miniaturisation could be identified. After comparing the various technologies which can be used to build the miniaturised chloride ion detection, the area which was found to be most promising was one based on potential measurement using galvanic voltage measurement.