Wire-Based Detection of Corrosive Salts in Concrete

摘要

This paper presents an iron wire trigger mechanism that will be used for a new generation of low-cost corrosion sensors that are wireless and do not require batteries or any other external power sources. The corrosion rates for thin sensor wires, 0.065 to 0.25 mm in diameter, were investigated in sodium chloride solutions and compared with the mass loss from steel coupons under similar conditions. The 0.125 and 0.065 mm wires were embedded in concrete and subjected to accelerated corrosion testing. These wires behaved similarly to mild reinforcing steel used in concrete structures and trigger at predictable chloride levels and are suitable for uses as trigger for corrosion. Prototype sensors, constructed using commercial radio-frequency identification tags with a section of the antenna replaced by a wire trigger, embedded in concrete and stopped responding at reproducible chloride concentrations. These results demonstrate the methodology to create successful radio-frequency identification based corrosion sensors.