Permanent Cap Grout Retention for Post-Tensioned Concrete Anchors

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Solution Overview

Problem

In post-tensioned concrete structures, there is a challenge in ensuring a secure and sealed connection at the stressing-end anchor, which is critical for maintaining the integrity and durability of the concrete member.

Innovation Solution

A permanent cap is designed to couple with and fluidly seal to the post-tensioned concrete anchor, featuring a grout retention feature to retain filling material within the cavity, thereby preventing delamination and ensuring a secure seal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a permanent cap is used to seal the stressing-end anchor, then the reliability of the connection is improved, but the device complexity increases

Engineering Contradiction:
Improveconnection integrityVSAvoidcap structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The permanent cap is divided into distinct functional segments: a cap body for sealing, a grout retention feature for material containment, and coupling mechanisms for attachment. This segmentation allows each component to perform its specific function efficiently while maintaining overall system reliability without excessive complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The grout retention feature is nested within the cap body structure, with the retention feature forming an internal cavity that holds grout or filling material. This nested configuration ensures that the sealing and grout retention functions are integrated in a compact manner, improving reliability while minimizing added complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If grout retention feature is added to retain filling material, then the reliability is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvesealing effectivenessVSAvoidcap fabrication
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The grout retention feature is merged with the cap body as an integrated structure rather than a separate component. This combining of functions into a single manufactured part improves sealing effectiveness while simplifying the manufacturing process by reducing the number of assembly steps and components required.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cap body serves multiple functions simultaneously: it provides the sealing surface, contains the grout retention feature, and includes coupling mechanisms for attachment to the anchor. This multi-functionality improves reliability through better sealing while easing manufacture by consolidating multiple features into a single component.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Duration of action of stationary object

If fluid sealing is implemented at the anchor, then the durability is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveanchor durabilityVSAvoidseal interface tolerance
Core Design Contradiction:
Duration of action of stationary objectVSManufacturing precision

Solution Approach 1:

The cap body incorporates a flexible sealing interface that can accommodate minor variations in anchor surface geometry. This flexible sealing mechanism improves durability by maintaining effective sealing despite moderate manufacturing tolerances, while the cap's rigid structure provides the necessary structural support.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The design includes built-in compensation features in the sealing interface that anticipate and accommodate potential manufacturing variations. By designing the seal to be tolerant of expected dimensional variations, the system achieves improved durability without requiring extremely tight manufacturing precision.

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

Data Source

PatentEP3146120B1Modified permanent cap
Publication Date: 2025.04.30 SORKIN FELIX L
  • EP3146120B1 patent drawingFigure 1a~1b
  • EP3146120B1 patent drawingFigure 1c~1e
  • EP3146120B1 patent drawingFigure 2a~2b

AI summary

A permanent stressed end cap for a post tensioned concrete member includes a grout retention feature adapted to retain a filler material within a void formed by a pocket former. The grout retention feature may be a generally knob or mushroom shaped, hex-headed, or square body extending from the cap. The grout retention feature may include one or more protrusions extending from the exterior of the cap. The grout retention feature may include one or more surface textures on the exterior of the cap.