Electrolyte-Stream Corrosion Assessment for Inaccessible Metal Elements

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Solution Overview

Problem

Existing methods for assessing corrosion on metal elements in structures like bridges and tunnels are invasive, destructive, and limited by accessibility, failing to detect corrosion in inaccessible areas and increasing safety and economic risks.

Innovation Solution

A method using a stream of electrolyte to establish an electrically conductive connection between an electrode and a metal element or its covering material, allowing non-destructive electrochemical measurements to assess corrosion states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If core drillings or probing windows are used to access metal elements, then electrochemical measurements can be performed, but the procedure is invasive and difficult to perform due to lack of accessibility

Engineering Contradiction:
Improveelectrochemical measurement capabilityVSAvoidaccessibility to structure
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent introduces a conductive electrolyte solution as an intermediary medium that bridges the gap between the electrode and the metal element. This electrolyte solution can be applied through accessible areas (such as cracks, joints, or surface openings) to establish electrical contact without requiring direct physical access to the metal element itself, thus resolving the accessibility problem while enabling electrochemical measurements.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical drilling and chiselling operations with a chemical/electrochemical approach. Instead of mechanically creating access holes to reach the metal element, the system uses electrolyte solution application to establish electrical contact, substituting mechanical intrusion with a non-invasive chemical medium that can penetrate through existing openings or cracks in the concrete structure.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If core drillings are performed to extract samples, then local corrosion assessment is possible, but possibly dangerous corrosion phenomena in proximity or outside drill holes cannot be assessed

Engineering Contradiction:
Improvelocal corrosion detectionVSAvoidcorrosion assessment coverage
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent transitions from point-based local measurement (through discrete drill holes) to area-based distributed measurement. By applying electrolyte solution across multiple locations and using electrical potential field measurements, the system can assess corrosion over extended areas and along the entire length of metal elements, adding spatial dimensionality to the corrosion assessment and eliminating blind spots between measurement points.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent creates a universal measurement approach that can assess corrosion at multiple locations simultaneously through electrical potential field measurements. The electrolyte solution application system can be used at various access points (cracks, joints, surface openings) to establish contact, making the same methodology applicable throughout the entire structure without requiring different procedures for different locations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If reference electrode is brought into electrical contact with concrete structure, then potential field measurements can be performed, but excavation of material covering concrete structure is required

Engineering Contradiction:
Improvepotential field measurementVSAvoidexcavation of covering material
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent uses conductive electrolyte solution as an intermediary that enables electrical contact between the reference electrode and the concrete structure without requiring excavation. The electrolyte solution can be applied through existing surface openings, cracks, or joints in the concrete covering, allowing the reference electrode to establish contact with the metal element or concrete structure while preserving the integrity of the covering material.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If heavy machinery and scaffolding constructions are used for bridge and tunnel inspections, then access to concrete structure is achieved, but safety hazards and costs increase

Engineering Contradiction:
Improveaccess to concrete structureVSAvoidsafety hazards
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent replaces heavy mechanical access systems (machinery and scaffolding) with a chemical/electrochemical measurement approach. By using electrolyte solution application through accessible surface openings, the system eliminates the need for physical access structures, thereby removing associated safety hazards while maintaining measurement capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables non-invasive, cost-effective assessment of corrosion across large areas, providing spatial information on corrosion states without excavation or physical contact, reducing safety hazards and costs.

Implementation Method 1

an electrode (5) is in electrically conductive connection with an electrolyte volume (4) positioned outside a metal element (1) or a material (3) that is electrolytically conductive or can be made electrolytically conductive and that is at least partially covering the metal element (1), and wherein the electrolyte volume (4) is brought into electrically conductive contact with the metal element (1) or the material (3) via a stream of electrolyte

Methodology Applied
Scientific EffectElectrical conduction through electrolyte: Conduction (electrical)

Implementation Method 2

an electrochemical measurement indicative of a state of corrosion on the metal element (1) is carried out

Methodology Applied
Scientific EffectElectrochemical measurement: Electrodeposition

Data Source

PatentEP4603821A1Method, device and system for assessing corrosion phenomena on at least one metal element
Publication Date: 2025.08.20 ETH ZURICH
  • EP4603821A1 patent drawingFigure 1
  • EP4603821A1 patent drawingFigure 2
  • EP4603821A1 patent drawingFigure 3

AI summary

The application relates to a method for assessing corrosion phenomena on at least one metal element (1), wherein an electrode (5) is in electrically conductive connection with an electrolyte volume (4) positioned outside a metal element (1) or a material (3) that is electrolytically conductive or can be made electrolytically conductive and that is at least partially covering the metal element (1), and wherein the electrolyte volume (4) is brought into electrically conductive contact with the metal element (1) or the material (3) via a stream (10) of electrolyte, and wherein an electrochemical measurement indicative of a state of corrosion on the metal element (1) is carried out. The application further relates to a device (11) and a system (100) for assessing corrosion phenomena on at least one metal element (1).