Electrochemical measurement system and method for monitoring a concrete structure

An assembly comprising at least two electrochemical measurement systems for monitoring a concrete structure comprising a reinforcement bar, wherein the at least two systems are mechanically coupled so as to form a longitudinal series of electrodes or multiple parallel lines of electrodes;

• each system comprising:
• at least six electrodes configured to be placed in contact with a surface of the concrete structure and arranged in a predefined spatial configuration;
• comprising:
• at least two emitting electrodes configured to inject a plurality of electrical signals into the concrete structure;
• at least four receiving electrodes configured to be combined in pairs;
• wherein each pair of electrodes receives a plurality of electrical signals, originating from an explored zone of the concrete structure;
• wherein the emitting electrodes and the receiving electrodes are disposed inline;
• an acquisition module configured (i) to control the emitting electrodes and receiving electrodes, and (ii) to acquire and store in a memory the plurality of electrical signals;
• a processing module configured to:
• calculate apparent resistivity values and apparent chargeability values for each plurality of electrical signals;
• receive a model comprising a geometric disposition of the reinforcement bar in the concrete structure, initial values of resistivity and chargeability for the reinforcement bar volumes and initial values of resistivity and chargeability for the concrete volumes;
• perform inversion using the model, the apparent resistivity values and the apparent chargeability values so as to obtain the inversed resistivity values and the inversed chargeability values, and from these values, process at least one output characteristic of the concrete structure associated to each explored zone from which the plurality of signals originates;
• wherein one output characteristic of the concrete structure is the corrosion rate of the reinforcement bar;
• and
• an image reconstruction module configured to generate an image of the distribution of the output characteristics of the concrete structure in the explored zones, which is an in-depth section of the concrete structure below the aligned electrodes.

A method for monitoring a concrete structure comprising a reinforcement bar, said method comprising the following steps:

• receiving a plurality of electrical signals, originating from an explored zone of the concrete structure, acquired using electrochemical measurement system comprising at least six electrodes;
• receiving a model comprising a geometric disposition of the reinforcement bar in the concrete structure, initial values of resistivity and chargeability for the reinforcement bar volumes and initial values of resistivity and chargeability for the concrete volumes;
• using the model to calculate for each plurality of electrical signals at least one induced polarization potential response value and one apparent resistivity value, and from these values, process at least one output characteristic of the concrete structure associated to each explored zone from which the plurality of signals originates;
• wherein one output characteristic of the concrete structure is the corrosion rate of the reinforcement bar;
• and
• generating an image of the distribution of the output characteristics of the concrete structure in the explored zones.