Vibrating Grouting Head Seals Guardrail Sheath in Concrete Slab

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Solution Overview

Problem

The existing method for inserting tubular metal guardrails into hollow-core concrete slabs results in inadequate fixation, leading to deformation and a radial space between the sheath and the hole in the upper wall, which compromises the structural integrity and holding capacity of the guardrail.

Innovation Solution

A method involving the use of a vibrating grouting head to tighten the concrete around the tubular sleeve, utilizing vibrations to seal the sheath with the upper wall through thixotropic effects, ensuring a rigid and secure connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a steel rod is pushed into the upper wall to form a hole and the sheath is engaged, then the sheath can be installed in the slab, but the upper wall is greatly deformed and a radial space is created between the sheath and the hole, resulting in inadequate fixation

Engineering Contradiction:
Improveease of sheath installationVSAvoidprecision of sheath positioning
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

A vibrating grouting head is applied to the upper wall around the hole to tighten the concrete around the sheath through thixotropic effect, eliminating the radial space and sealing the sheath with the upper wall without requiring excessive force that would cause deformation

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The concrete's rheological properties are changed by applying vibrations, which induce thixotropic behavior in the fresh concrete, allowing it to flow and fill the radial space between the sheath and the hole, then harden to provide secure fixation

Inventive Principle:
Principle #35Parameter changes

2Strength

If the sheath is implanted by tapping with a sledgehammer to plant its lower end in the lower wall, then the lower end is correctly planted, but the upper portion is not effectively held by the upper wall, compromising the guardrail holding function

Engineering Contradiction:
Improveholding capacity of sheathVSAvoidreliability of guardrail fixation
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

Vibrations are applied to the upper wall around the hole to activate the thixotropic effect in the fresh concrete, causing the concrete to tighten and seal around the sheath, providing effective holding for both the lower and upper portions of the sheath

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The mechanical impact method (sledgehammer) is supplemented by a vibration-based grouting method, replacing the need for excessive impact force with a controlled vibration process that achieves secure fixation through thixotropic consolidation of the concrete

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 method achieves a very rigid connection of the sheath with the concrete slab, enhancing the structural integrity and preventing issues like deformation and radial gaps, while ensuring effective sealing against freezing.

Implementation Method 1

application of vibrations with a vibrating grouting head, at the level of the upper face of the upper wall around the hole, to tighten the concrete around the sleeve by thixotropic effect in order to seal the sleeve with the upper wall

Methodology Applied
Scientific EffectThixotropic effect: Thixotropy

Data Source

PatentEP2581190B1Verfahren zum Einfügen eines Geländerschafts in eine Betonwabenplatte
Publication Date: 2013.12.25 KP1
  • EP2581190B1 patent drawingFigure 1~3
  • EP2581190B1 patent drawingFigure 4~6
  • EP2581190B1 patent drawingFigure 7~10

AI summary

The method involves forming a hole in an upper wall (3) of an alveolate flagstone (1). A tubular sleeve (11) is inserted through the hole and toward a lower wall. A lower end of the sleeve is depressed in part of thickness of the lower wall of the alveolate flagstone, by applying percussions to the sleeve. Vibrations are applied to a vibrating sealing head (13) on level of an upper face of the upper wall around the hole so as to tighten the flagstone around the sleeve by thixotropic effect to seal the sleeve with the upper wall.