A Prototype of an Electromagnetic Induction Sensor for Non-Destructive Estimation of the Presence of Corrosive Chemicals Ensuing Concrete Corrosion

Abstract

The corrosion of steel reinforcement in concrete often leads to huge unbudgeted expenses for maintaining, monitoring and renovating an infrastructure. This is mainly due to the presence of salts or chemical chlorides that pose a danger to the concrete structures. The determination of the existence of these corrosive salts is vital for defining the service life of concrete. This research looked at developing an electromagnetic induction (EMI) sensor for the detection of corrosive salts. The first design adopted a single-loop coil (SLC) concept, and the second was based on a multiple-loop coil (MLC) one using copper wire. Tests were conducted on these two techniques, and with the results obtained, the latter seemed more promising; thus, a prototype sensor was developed using the MLC concept. As this new prototype sensor was able to detect the manifestation of chemical contents in a concrete structure, it could be used as a non-destructive evaluation (NDE) technique for the detection of corrosive chemicals in concrete and has the further possibility of detecting corrosion in concrete.

Evaluation of Concrete Corrosion using EMI Sensor

“…Corrosion in RC structure is an oxidation process that depends on the environment and geographic location it is exposed to such as rain, humidity, sea water and other chemicals [2,3].…”

“…Reinforced Concrete (RC) is the most momentous and composite element in civil engineering and construction purposes which makes the building strong and more durable [1]. The current state-of-the-art gives an overview that corrosion of steel reinforcement is the main cause of deterioration and early failure of RC structures, this leads to enormous costs for inspection, maintenance, restoration and replacement of infrastructure [2,3]. However, concrete corrosion process takes decades to occur depending on the environmental condition.…”

“…According to literature [2,3], several methods have been developed and used for evaluate the degree of corrosion in concrete structures mainly for coastal environment. Previously, destructive techniques were used to assess the condition, which has few disadvantage such as time consuming and money.…”

“…Whereas common methods used for monitoring in RC structures are visual inspection, polarization resistance, OCP, and other electrochemical methods. Interestingly, electromagnetic induction (EMI) is another techniques which could be used to monitoring and assessing RC structure [3,15].…”

“…The designed prototype works with a MLC sensor, which consists of primary and secondary search coils. The search coil acts like magnetic antenna which sends and receives AC signal pulse [3,15].…”