Expansion Joint Tape With Segmented Cavities for Sealing

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Solution Overview

Problem

Conventional expansion joint tapes fail to provide a permanent, reliable seal between building components due to limited flexibility, relative movements causing stress, and leakage issues, especially under temperature changes and varying material expansions, leading to gaps, cracks, and moisture penetration.

Innovation Solution

An expansion joint tape with a sealing strip featuring continuously extending cavities and multiple webs along its central longitudinal axis, triangular or mushroom-shaped projections for anchoring, and swelling bands within channels to accommodate movement and pressure, ensuring secure embedding and sealing capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional expansion joint tapes are used to seal joints between building components, then the joint sealing function is provided, but the tapes fail under relative movements causing stress, leading to gaps, cracks, and leakage

Engineering Contradiction:
Improvejoint sealing reliabilityVSAvoidresistance to stress from relative movements
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The sealing strip is divided into multiple segments by transverse grooves, creating individual cavities that can independently deform and accommodate relative movements between building components. This segmentation allows each cavity to absorb stress without causing failure of the entire sealing structure, preventing gaps and cracks that would compromise reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the physical parameters of the sealing material by incorporating cavities with specific volume ratios (30-70% of total volume) and configuring webs with particular thickness ratios. These parameter changes enable the material to exhibit both elasticity for movement accommodation and sufficient strength to resist stress from thermal expansion and structural shifts, maintaining sealing reliability under varying conditions.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the sealing strip is made more flexible to accommodate movements, then adaptability to relative movements improves, but structural strength decreases leading to tearing and cracking

Engineering Contradiction:
Improveflexibility to accommodate relative movementsVSAvoidresistance to tearing and cracking
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The sealing strip functions as a composite structure combining elastic material with integrated cavities and reinforcing webs. This composite design provides both the flexibility needed to accommodate relative movements and the structural strength to prevent tearing, as the webs distribute stresses throughout the structure while the elastic material allows deformation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The cavities act as pre-configured cushioning elements that absorb and distribute stresses from relative movements before they can propagate through the sealing strip. By providing this cushioning capacity in advance through the cavity structure, the sealing strip can accommodate movements without developing the high stresses that would lead to tearing or cracking.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Adaptability or versatility

If the central section is made larger to provide sufficient expansion capacity, then the expansion capability improves, but the distance from side bands increases reducing coupling effectiveness

Engineering Contradiction:
Improveexpansion capacityVSAvoidcoupling force between side bands and concrete
Core Design Contradiction:
Adaptability or versatilityVSForce

Solution Approach 1:

The sealing strip is segmented into multiple cavities rather than using a single large central section. This segmentation provides sufficient total expansion capacity through the cumulative volume of multiple smaller cavities while keeping each cavity close to the side bands, maintaining effective coupling between the sealing strip and concrete through the webs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of increasing the lateral dimensions of a central section, the patent utilizes the longitudinal dimension by creating multiple cavities along the length of the sealing strip. This dimensional approach provides the necessary expansion capacity while maintaining close proximity to side bands at multiple locations, ensuring effective coupling throughout the structure.

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

4Strength

If rows of webs are arranged in concrete walls to hold the joint tape, then anchoring capability improves, but the flexibility of the joint tape is severely limited preventing uniform expansion

Engineering Contradiction:
Improveanchoring capability in concreteVSAvoidflexibility for uniform expansion
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

Instead of arranging webs in rows within the concrete as conventional tapes do, this patent integrates the webs as part of the sealing strip structure itself, with cavities positioned between the webs. This inverted approach maintains anchoring capability through the web-concrete interface while preserving the flexibility of the sealing strip material, allowing uniform expansion without the rigid constraints imposed by conventional web arrangements.

Inventive Principle:
Principle #13The other way round (Inversion)

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

The tape maintains a watertight seal under various movements and pressures, preventing moisture and water ingress, while its design allows for uniform expansion and resistance to tearing, ensuring a durable and effective joint sealing solution.

Implementation Method 1

swelling bands within channels to accommodate movement and pressure

Methodology Applied
Scientific EffectSwelling: Intumescent Materials

Implementation Method 2

The elastic material comprises plastic-like and/or rubber-like material

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3428357B1Expansion joint tape and compression tape arrangement for permanent reliable joint sealing
Publication Date: 2024.07.03 DEFLEX FUGENSYSTEME GMBH
  • EP3428357B1 patent drawingFigure 1
  • EP3428357B1 patent drawingFigure 2
  • EP3428357B1 patent drawingFigure 3

AI summary

The invention relates to an expansion joint tape for the permanent, reliable sealing of joints, such as expansion joints between or in structures, buildings, tunnel structures, etc.and/or parts thereof with an elastic, preferably plastic and/or rubber-like, material, with a sealing strip, the sealing strip having cavities extending continuously along its central longitudinal axis, wherein webs are formed on the sides of the sealing strip, the head regions of the webs facing away from the sealing strip are drawn in to form channels, the webs are formed on the sides of the sealing strip in the area of ​​the cavities, and triangular projections extending along the central longitudinal axis are formed on the opposite sides of the sealing strip and on the sides of the webs, and a compression band arrangement for the permanent, reliable sealing of marginal joint areas in tunnel structures with inner jaw, outer jaw and compression band.