Liquid-Tight Cement Layer Structure for Leak Detection

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Solution Overview

Problem

Existing liquid-tight layer structures for building surfaces, such as those used in swimming pools, face challenges in detecting small imperfections during production, leading to potential medium-term damage, and previous solutions like full-surface metal inserts are costly, difficult to produce, and pose disposal issues.

Innovation Solution

A liquid-tight layer structure composed of a conductive cement-based first layer and a non-conductive cement-based second layer, where the first layer has a surface resistance of ≤10^5 Ω and the second layer has a volume resistance of ≥10^8 Ω, allowing for leak detection using a high voltage test, and both layers are easily producible and disposable.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a full-surface metal insert is used as a counter-electrode for leak detection, then leak detection capability is improved, but manufacturing complexity increases and costs rise

Engineering Contradiction:
Improveleak detection capabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the expensive, difficult-to-produce metal insert with a disposable aluminum foil layer that is applied temporarily during testing and then removed. This foil serves as the counter-electrode for leak detection but does not need to be permanently installed, significantly reducing manufacturing complexity and cost while maintaining leak detection capability.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent introduces a liquid conductive medium as an intermediary between the aluminum foil counter-electrode and the sealing layer. This liquid medium ensures good electrical contact for leak detection without requiring direct bonding between the metal insert and the sealing material, simplifying the application process and expanding compatibility with different sealing materials.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a full-surface metal insert is used as a counter-electrode, then leak detection is enabled, but adhesion to sealing materials becomes problematic

Engineering Contradiction:
Improveleak detection capabilityVSAvoidadhesion to sealing materials
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The liquid conductive medium acts as an intermediary that bridges the aluminum foil and the sealing layer. It provides the necessary electrical contact for leak detection without requiring permanent adhesion, thus avoiding the adhesion problems that arise when trying to bond metal directly to various sealing materials like plastic or bitumen.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The aluminum foil is applied as a temporary element during the testing phase only. It does not need to adhere permanently to the sealing material, as it is removed after testing. This temporary application eliminates the need for strong adhesion properties.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If a full-surface metal insert is used, then leak testing can be performed, but corrosion risk increases affecting durability

Engineering Contradiction:
Improveleak testing capabilityVSAvoiddurability
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The aluminum foil counter-electrode is used only temporarily during the leak testing process and is then removed. It is not left in place as a permanent component, thereby eliminating the risk of corrosion that would affect long-term durability of the sealing system.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The potentially corrosive metal element is extracted from the permanent structure and used only as a temporary testing tool. After serving its purpose in leak detection, it is removed from the system, preventing any long-term corrosion issues that could compromise the sealing layer or building structure.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If plastic or bitumen is used for primer and sealing layer, then sealing effectiveness is achieved, but disposal problems arise

Engineering Contradiction:
Improvesealing effectivenessVSAvoiddisposal ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the material parameter of the primer layer from conventional plastic or bitumen to a cement-based material. This material substitution maintains the sealing effectiveness required for the application while dramatically improving disposal characteristics, as cement-based materials are more environmentally friendly and easier to dispose of or recycle compared to plastic and bitumen.

Inventive Principle:
Principle #35Parameter changes

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

This solution enables reliable and cost-effective production and leak testing of liquid-tight surfaces, with the cement-based materials ensuring easy handling and disposal, and the layer structure effectively prevents water ingress, ensuring long-term durability.

Implementation Method 1

The first (in particular full-surface) layer based on cement has a surface resistance measured according to DIN EN 61340-4-1 VDE 0300-4-1:2016-04 of less than or equal to 10^5 Ω and the second layer based on cement has a volume resistance of at least 10^8 Ω

Methodology Applied
Scientific EffectElectrical conductivity difference: Electrical Resistance

Implementation Method 2

providing a counter-electrode in the form of a full-surface metal insert, such as aluminum foil, between a sealing layer made of plastic or bitumen and the structure in order to check the sealing of parts of a structure against water

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3628788B1Liquid-tight layer structure and method for producing the same
Publication Date: 2023.06.07 SOPRO BAUCHEM
  • EP3628788B1 patent drawingFigure 1~2

AI summary

A liquid-tight layer structure for building surfaces is disclosed, comprising a first layer (30) based on cement, whose surface resistance according to DIN EN 61340-4-1 VDE 0300-4-1:2016-04 is less than or equal to 10⁵ Ω, and a second layer (40) whose volume resistivity according to DIN EN 61340-4-1 VDE 0300-4-1:2016-04 is greater than or equal to 10⁸ Ω and whose water exposure class according to DIN 18534-1 - 2017-07 is W1-I to W3-I. The first layer (30) is arranged between a surface (10) to be sealed and the second layer (40). Furthermore, a method for producing the liquid-tight layer structure and a method for verifying the liquid-tight layer structure for leakage are disclosed.