Sealed Dowel Bar Connector for Corrosion-Resistant Movement Joints
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Solution Overview
Problem
Existing temporary movement joints in post-tensioned concrete structures face issues such as corrosion, high manufacturing costs, difficulty in sealing, and potential failure under excessive forces, leading to reduced longevity and integrity of the floor plates.
Innovation Solution
A connector comprising a housing with a sealing screen and dowel bar system that accommodates lateral, vertical, and telescopic movements while maintaining a sealed engagement, using an elastic membrane and abutments to ensure the dowel bar remains sealed and securely positioned, with a design that allows for easy installation and sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If temporary movement joints are made from corrosion resistant materials like stainless steel, then reliability is improved, but manufacturing cost increases significantly
Solution Approach 1:
The connector is divided into two functional parts: a housing made from standard materials that provides structural support, and an internal sealing mechanism that protects the tendon. This segmentation allows the use of less expensive materials for the housing while maintaining corrosion protection through the sealing system.
Solution Approach 2:
A sealing membrane acts as an intermediary between the external environment and the tendon, preventing corrosion without requiring the entire connector to be made from expensive corrosion-resistant materials. The sealant fills the gap between the dowel bar and housing, creating a protective barrier.
2Strength
If members are installed in both surfaces, then strength is improved, but device complexity increases
Solution Approach 1:
The connector combines the functions of both first and second members into a single integrated housing structure installed in only the first surface. The housing contains the sealing mechanism and provides all necessary structural support, eliminating the need for separate members in both surfaces while maintaining force resistance.
3Reliability
If sealing mechanisms are added to prevent corrosion, then reliability is improved, but device complexity increases
Solution Approach 1:
A flexible sealing membrane is used to create a simple yet effective barrier between the external environment and the tendon. The membrane can accommodate movements while maintaining the seal, preventing corrosion without requiring complex mechanical sealing components.
Solution Approach 2:
The sealant automatically fills and seals the gap between the dowel bar and housing through capillary action or pressure differential, creating a self-sealing mechanism that maintains corrosion protection without requiring active control or complex components.
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 connector effectively transfers precompression forces, prevents corrosion, and maintains structural integrity by allowing relative movement while ensuring a sealed environment, reducing maintenance and construction time, and lowering costs.
Implementation Method 1
the sealing screen incorporating an elastic membrane surrounding an aperture, where, the aperture is adapted to sealingly engage a dowel bar and where, movement of the dowel bar laterally, vertically or telescopically is accommodated for by the elastic membrane
Data Source
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AI summary
An improved connector (10) for use in forming joints between two surfaces. The improved connector (10) comprises a housing (12) having an enlarged seal housing (56) at a first end (20) and a sealing screen (16) adapted for receipt in the enlarged seal housing (56). The sealing screen (16) incorporates an elastic membrane (84) that surrounds an aperture (94). The aperture (94) is adapted to sealingly engage a dowel bar (18). This engagement means that movement of the dowel bar (18) laterally, vertically or telescopically is accommodated for by the elastic membrane (84) in a manner that ensures that the dowel bar (18) remains sealing engaged by the aperture (94).