Expansion Joint Seal with Segmented Core and Adhesive Mounting
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Solution Overview
Problem
Existing expansion joint seal systems face challenges with durability, flexibility, and longevity due to damage from vandalism, environmental factors, and mechanical shear, particularly in areas subject to temperature changes and heavy traffic, leading to inflexibility and cohesive or adhesive failure, and often require expensive mechanical attachments that shorten their lifespan.
Innovation Solution
The proposed expansion joint seal system incorporates a cover plate, a vertically-oriented elongate rail, and an elastically-compressible core, where the rail is detachably attached to the cover plate and the core is designed to maintain compression, inhibiting water and contaminant transmission, with optional features like a tether to prevent sagging and a stabilizing spring for enhanced performance under seismic loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an elastically-compressible core system with a continuous spine is used to provide sealing, then the seal can accommodate joint movement through compression and expansion, but the continuous spine propagates deflection along the length and takes on compression set when repeatedly exposed to lateral forces
Solution Approach 1:
The continuous spine is divided into discrete, separate segments along the length of the expansion joint. Each segment acts independently, preventing deflection propagation that occurs in continuous spine systems. The segments are spaced apart rather than forming an unbroken structural element, allowing each to compress and expand locally without affecting adjacent segments.
Solution Approach 2:
The material properties of the elastically-compressible core are optimized to resist compression set under repeated lateral loading. The foam material is selected or formulated to maintain its elastic recovery characteristics even after numerous compression cycles, addressing the durability issue of traditional foam cores that degrade over time.
2Strength
If cover plates are mechanically attached to the deck or joint substrate through drilling, then the cover plate is securely anchored, but the mechanical attachment process is complex and may damage the substrate
Solution Approach 1:
The mechanical attachment system (drilling and fastening) is replaced with an adhesive bonding system. The cover plate is secured to the joint substrate using adhesive applied to the bonding surface, eliminating the need for drilling holes, inserting fasteners, and tightening bolts. This substitution maintains secure anchoring while dramatically simplifying the installation process.
3Reliability
If the joint seal system extends above the adjacent substrates, then it provides sealing, but it presents a tripping hazard and is susceptible to damage from vandalism and environmental factors
Solution Approach 1:
The seal system is positioned below the surface of the adjacent substrates rather than extending above them. By relocating the sealing function to a subsurface position, the system maintains its sealing effectiveness while eliminating the tripping hazard and reducing exposure to vandalism, environmental weathering, and physical damage from traffic.
Solution Approach 2:
The seal system is nested within the joint gap between substrates, with the elastically-compressible core fitting into the space between the first and second substrates. The cover plate may extend partially or fully below the substrate surface, nesting the sealing components within the joint structure rather than protruding outward.
4Adaptability or versatility
If the expansion joint size increases, then it accommodates greater movement, but it becomes more difficult to address surface contact and tripping hazard issues
Solution Approach 1:
Regardless of the expansion joint size, the seal system is positioned below the substrate surface rather than extending above it. This dimensional relocation ensures that even large expansion joints do not create tripping hazards or expose the sealing components to damage, as the sealing function is performed in the subsurface joint space.
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 configuration provides a durable, flexible, and long-lasting seal that can withstand significant movement and loads, maintaining fire and water resistance while reducing the risk of damage from mechanical strikes, and can be easily maintained or repaired, with the potential for extended lifespan beyond five years without the need for costly mechanical attachments.
Implementation Method 1
an elastically-compressible core, where the rail is detachably attached to the cover plate and the core is designed to maintain compression, inhibiting water and contaminant transmission
Data Source
AI summary
A system for creating a durable seal between adjacent panels, including those which may be subject to temperature expansion and contraction or mechanical shear having a cover plate, a rail, and an elastically-compressible core adjacent the rail.