Tendon Anchorage Using Casting Compound and Collar
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Solution Overview
Problem
High-strength tendon anchoring in components with limited accessibility poses a challenge, as existing methods require extensive anchorage length and are not economically feasible, especially for structures like foundations where rear access is restricted.
Innovation Solution
A tendon anchoring system utilizing a non-positive connection with a hardening casting compound and a circumferential collar to transfer prestressing forces effectively, allowing for secure anchoring with a short anchorage length, even in confined spaces, by optimizing the bond between the tie rod, casting compound, and duct wall.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If blind holes with expanding heads are used for anchoring, then anchoring can be performed from one side only, but the anchorage length becomes excessively long and economically unfeasible
Solution Approach 1:
The invention changes the bonding mechanism parameters by using a hardening casting compound with specific adhesive properties that enables high-strength bonding over short lengths. The casting compound creates a bond strength that allows effective force transfer in a compact anchorage length, resolving the contradiction between one-sided accessibility and excessive anchorage length.
2Ease of operation
If adhesive anchors are used, then anchoring can be performed in confined spaces, but the anchorage forces are limited to well below 100 kN
Solution Approach 1:
The invention uses a composite anchoring system combining a tie rod with a hardening casting compound that has both adhesive and structural properties. This composite approach enables the system to achieve high anchorage forces (600-1500 kN) while maintaining the advantage of confined space installation, overcoming the force limitation of conventional adhesive anchors.
3Force
If conventional anchoring methods are used, then high forces can be anchored, but the anchorage length requires extensive space that is not available in certain components
Solution Approach 1:
The invention changes the bonding interface parameters by using a hardening casting compound that cures to form a high-strength bond over a short length. This enables effective force transfer in a compact anchorage length, resolving the contradiction between high anchorage force and excessive anchorage length.
4Productivity
If short anchorage length is used, then installation is more economical and practical, but secure anchoring of high forces cannot be ensured
Solution Approach 1:
The invention uses a composite system of tie rod and hardening casting compound where the casting compound provides both adhesive bonding and structural support. This composite approach ensures secure anchoring of high forces (600-1500 kN) over short anchorage lengths, maintaining both installation efficiency and anchoring reliability.
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
Enables secure anchoring of high forces (up to 2000 kN) with anchoring lengths as short as 15 times the tie rod diameter, facilitating easy replacement of damaged tendons and reducing replacement costs, while ensuring long-term structural integrity.
Implementation Method 1
the prestressing rod is brought into a non-positive connection with the duct wall using a hardening casting compound. The anchoring length therefore corresponds to the anchoring depth of the tie rod required to transfer an existing tensioning force into the section of the channel filled with casting compound. This is decisively determined on the one hand by the bond in the contact area between the tie rod and the sealing compound and on the other hand by the bond in the contact area between the duct wall and the sealing compound.
Data Source
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AI summary
The invention relates to an arrangement and a method for the high-strength anchorage of a tendon (1) having a tie rod (4) in a structural element (3). To this end, the structural element (3) has a channel (17) in which the end of the tie rod (4) to be anchored is inserted. A force-locked connection with the wall of the channel (17) is created by means of a curable jointing compound (18). According to the invention, the tie rod (4) has at least one circumferential collar (12) in the region of the end to be anchored, which collar has a radial play with respect to the wall of the channel (17). In this way, it is possible to guarantee a high-strength anchorage for tendons (1) even with a short anchorage length in the channel (17).