Closed-Cell Expansion Joint Seal for Fire Resistance and Compressibility

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Solution Overview

Problem

Conventional expansion joint sealants fail to provide effective water and fire resistance while maintaining compressibility over time, often requiring high compression ratios and impregnation with solid fillers, which can lead to fatigue and limited movement capabilities.

Innovation Solution

A fire-resistant and water-resistant expansion joint seal system comprising foam members and interspersed intumescent members with a wave-like cross-section, which provides additional load support and allows for greater movement without the need for high compression ratios or extensive impregnation with solid fillers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional expansion joint sealants use high compression ratios and impregnation with solid fillers to improve water and fire resistance, then water and fire resistance is improved, but compressibility and movement capabilities deteriorate due to fatigue

Engineering Contradiction:

Improvewater and fire resistanceVSAvoidcompressibility and movement capabilities

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The expansion joint seal is divided into multiple foam members positioned at different heights within the joint. Each foam member can compress independently, allowing the system to maintain compressibility and movement capabilities while providing distributed water and fire resistance through the layered structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different foam members are positioned at specific heights (first foam member at lower height, second foam member at higher height) to provide localized sealing functions. This allows water and fire resistance to be achieved at critical locations without requiring the entire seal to be heavily impregnated with solid fillers, thereby maintaining overall compressibility.

Inventive Principle:

Principle #3Local quality

2Reliability

If conventional sealants are impregnated with solid fillers to improve water resistance, then water resistance is improved, but the sealant becomes less compressible and more prone to fatigue

Engineering Contradiction:

Improvewater resistanceVSAvoidcompressibility and fatigue resistance

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The seal system uses multiple separate foam members instead of a single heavily impregnated sealant. Each foam member remains relatively uncompressed and can deform independently, maintaining compressibility and reducing fatigue while collectively providing water resistance through their distributed positioning.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system combines multiple foam members with different positioning and potentially different material properties to create a composite sealing system. This allows the integration of water resistance and compressibility functions across different components rather than requiring a single material to achieve both properties.

Inventive Principle:

Principle #40Composite materials

3Adaptability or versatility

If expansion joint seals are designed to accommodate large movements and seismic activity, then movement capabilities are improved, but water and fire resistance may be compromised

Engineering Contradiction:

Improvemovement capabilitiesVSAvoidwater and fire resistance

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

Multiple foam members positioned at different heights can move and compress independently to accommodate large joint movements and seismic activity. Meanwhile, their distributed positioning ensures that water and fire resistance is maintained at multiple levels, preventing compromise of sealing function despite high adaptability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The foam members are designed to dynamically respond to joint movement by compressing and expanding as needed. This dynamic behavior allows the seal to accommodate seismic and thermal movements while maintaining water and fire resistance through the continuous presence of foam members at critical heights.

Inventive Principle:

Principle #15Dynamics

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 system effectively seals against water and fire, maintains compressibility, and supports high movement capabilities, including seismic and cycling requirements, while allowing vapor pressure to escape, thus addressing the limitations of conventional sealants.

Implementation Method 1

A vapor permeable water and fire-resistant closed cell foam-based expansion joint seal

Methodology Applied

Scientific EffectClosed cell foam structure: Foam

Implementation Method 2

A fire-resistant and water-resistant expansion joint seal system comprising foam members and interspersed intumescent members

Methodology Applied

Scientific EffectIntumescent expansion: Intumescent Materials

Implementation Method 3

allowing vapor pressure to escape

Methodology Applied

Scientific EffectVapor permeability: Porosity

Data Source

PatentUS11035116B2Vapor permeable water and fire-resistant expansion joint seal having a closed cell foam member, and permitting varied compressibility and height differentials

Publication Date: 2021.06.15 SCHUL INT COMPANY

AI summary

The present disclosure relates generally to systems for providing a durable water-resistant and fire-resistant foam-based seal in the joint between adjacent panels. A fire-resistant and water-resistant expansion joint seal is provided which includes one or more foam members and a plurality of intumescent members interspersed within the foam member or members to provide a spring recovery force and fire resistance.