Reinforcing Element Thread Structure for Deep Concrete Anchoring

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing connection arrangements face challenges in achieving strong anchoring, especially at large depths, with high screw-in resistance and risk of damage due to excessive torque, particularly in materials prone to cracking like concrete.

Innovation Solution

A reinforcing element with a cutting section and self-tapping cutting thread, where the cutting thread is shorter than the total length, and a conical transition section, combined with a hardenable mass that hardens to provide additional anchoring strength, minimizing screw-in torque and preventing unintentional removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a conventional screw with full-length threading is used for deep anchoring, then anchoring strength is improved, but insertion torque becomes excessively high causing damage risk

Engineering Contradiction:
Improveanchoring strengthVSAvoidinsertion torque
Core Design Contradiction:
StrengthVSForce

Solution Approach 1:

The screw is divided into two functional sections: a cutting section (first section) with cutting threads for initial anchoring, and a fastening section (second section) with fastening threads for final securing. This segmentation allows the cutting section to handle the high-stress insertion phase with lower torque requirements, while the fastening section provides the primary anchoring strength, thus resolving the contradiction between anchoring strength and insertion torque.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different thread types are applied to different sections of the screw: cutting threads with specific geometry (thread angle 30-45°, thread height 0.15-0.3 times pitch) in the cutting section for easy insertion, and standard fastening threads in the fastening section for strong anchoring. This local differentiation of thread quality optimizes each section's function, reducing overall insertion torque while maintaining anchoring strength.

Inventive Principle:
Principle #3Local quality

2Strength

If the cutting thread diameter is increased to improve anchoring, then anchoring strength is improved, but interference with steel reinforcements increases

Engineering Contradiction:
Improveanchoring strengthVSAvoidinterference with steel reinforcements
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The cutting thread diameter is specifically optimized to be only slightly larger than the borehole diameter (excess 0.5-2 mm), minimizing interference with steel reinforcements. Meanwhile, the fastening threads in the second section provide the necessary anchoring strength through proper thread geometry and engagement with the hardened material, thus achieving both goals simultaneously.

Inventive Principle:
Principle #3Local quality

3Strength

If a hardening compound is used to improve anchoring at great depths, then anchoring strength is improved, but the screw-in process becomes more complex

Engineering Contradiction:
Improveanchoring strength at great depthsVSAvoidscrew-in process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

A hardening compound is introduced into the borehole before inserting the screw. The compound hardens during or after the screw-in process, providing additional anchoring strength at great depths. This preliminary action simplifies the overall process by eliminating the need for complex post-installation anchoring mechanisms while the dual-thread design keeps insertion torque manageable.

Inventive Principle:
Principle #10Preliminary action

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 solution allows for reliable anchoring with reduced screw-in resistance, enhanced strength, and improved crack stabilization in materials, ensuring the reinforcing element is securely embedded without damage from excessive torque, while minimizing interference with steel reinforcements.

Implementation Method 1

A curable compound is filled into the borehole, which, after curing, provides additional anchoring of the reinforcing element in the borehole

Methodology Applied
Scientific EffectHardening/Curing:

Implementation Method 2

The compound creates a positive fit and prevents the reinforcing element from being unintentionally pulled out of the borehole

Methodology Applied
Scientific EffectPositive fit:

Implementation Method 3

under axial loading of the reinforcement element from the borehole, the cone angle exerts a spreading effect on the hardened material, pressing the hardened material against the inner wall of the borehole

Methodology Applied
Scientific EffectSpreading effect:

Implementation Method 4

The expanding effect is achieved primarily through expanding forces oriented at least partially radially with respect to the longitudinal axis, which act from the conical transition section, particularly along the circumferential direction around the longitudinal axis, against the hardened material

Methodology Applied
Scientific EffectExpanding forces:

Data Source

PatentEP4166799B1Reinforcing element for reinforcing a material and an arrangement with such a reinforcing element in the material
Publication Date: 2024.08.28 TOGE DUBEL
  • EP4166799B1 patent drawingFigure 1
  • EP4166799B1 patent drawingFigure 2

AI summary

A reinforcing element serves to strengthen a material (2), wherein the reinforcing element (9) comprises a core (10) having a longitudinal axis (13) and a core diameter (DK), with a cutting section (As) arranged at an inlet end (11) of the core (10), which has a cutting section length (Ls) oriented along the longitudinal axis (13), a cutting section diameter (Ds) oriented perpendicular to the longitudinal axis (13), wherein Ds > DK, and a cutting thread (15) with a cutting thread diameter (DG), wherein the cutting thread (15) has a thread length (LG) oriented along the longitudinal axis (13), with a conical transition section (AK) adjoining the cutting section (As) along the longitudinal axis (13) with a cone angle (k), wherein 0° < k < 90°, and with a torque transmission element (20).