Disposable Cap for Post-Tension Tendon Anchor Protection
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Solution Overview
Problem
Post-tensioned concrete structures face challenges in preventing fluid intrusion into tendon anchors, which can lead to corrosion and reduced structural integrity due to exposure to corrosive elements during the construction and tensioning processes.
Innovation Solution
A cap system is introduced that includes a cap body with an inner bore, designed to fit over the tendon and abut the tensioning end anchor, inhibiting fluid entry by frictional or press fit mechanisms, and featuring bayonet ramps or flanges for secure positioning, thereby protecting the tendon from external fluids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the tendon anchor is left exposed during construction and tensioning, then the construction process is simple and fast, but fluid intrusion occurs leading to corrosion and reduced structural integrity
Solution Approach 1:
The patent employs a disposable cap that is used temporarily during construction and tensioning to protect the tendon anchor from fluid intrusion. The cap performs its protective function during the critical construction phase and is then removed, eliminating the need for permanent complex sealing systems while maintaining structural integrity throughout the process.
Solution Approach 2:
The cap serves as an intermediary protective element between the tendon anchor and the corrosive environment. It temporarily mediates the interaction by blocking fluid access to the anchor during construction and tensioning, then is removed when no longer needed, simplifying the overall system while protecting against corrosion.
2Reliability
If a cap system is used to seal the tendon anchor, then fluid intrusion is prevented, but the installation and removal process becomes more complex
Solution Approach 1:
The cap is designed as a segmented component with a body portion and a separate closure element. This segmentation allows the cap to be easily installed by placing it over the tendon anchor and securing the closure, and equally easily removed by releasing the closure. The segmented design simplifies both installation and removal operations while maintaining effective sealing.
3Reliability
If the cap remains on the tendon after tensioning, then continuous protection is maintained, but it interferes with subsequent construction operations
Solution Approach 1:
The cap system is designed to be dynamic rather than static - it is installed when protection is needed during construction and tensioning, then removed when it would interfere with subsequent operations. This dynamic approach allows the system to adapt to different construction phases, providing protection when necessary and eliminating interference when the protective function is no longer required.
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 cap system effectively prevents fluid intrusion into the tendon anchors, reducing the risk of corrosion and maintaining the structural integrity of post-tensioned concrete members by sealing the tendon ends during construction and tensioning.
Implementation Method 1
inhibiting fluid entry by frictional or press fit mechanisms
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
The process includes forming a concrete form at least one end wall where the concrete form is adapted to receive concrete placed thereinto. The process also includes setting a fixed end anchor and a tensioning end anchor on at least one end wall where the fixed end anchor and tensioning end anchor are each adapted to receive a tendon. The process further includes threading the tendon through the fixed end anchor and tensioning end anchor such that a tensioning end portion of the tendon extends from the tensioning end anchor and placing concrete into the concrete form. The process includes installing a cap about the circumference of the tensioning end portion of the tendon. The cap includes a cap body. The cap body includes an inner bore, where the inner bore has a diameter corresponding to the outer diameter of the tendon.