Ductility Element for Reinforcing Concrete Structures
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Solution Overview
Problem
Concrete structures reinforced with high strength steel or FRP tendons lack ductility due to low strain capacity and linear elastic stress-strain behavior, leading to reduced deformability and ductility.
Innovation Solution
Incorporating a ductility element with weakened deformation zones between the tendon and anchor, which deforms under stress to increase the ductility of the reinforcement system, allowing for elongation or compression and distributing tensile forces evenly across the ductility element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high strength steel or FRP tendons are used for reinforcement, then the strength of the concrete structure is improved, but the ductility decreases due to low strain capacity and linear elastic stress-strain behavior
Solution Approach 1:
A ductility element is introduced as an intermediary component between the high strength tendon and the anchor. This ductility element has lower strength than the tendon and deforms plastically first under load, providing the desired ductility while the high strength tendon maintains the structural strength. The ductility element acts as a mediator that converts the brittle behavior of high strength materials into ductile system behavior.
Solution Approach 2:
The invention changes the strength parameter of the anchorage system by introducing a ductility element with controlled lower strength properties. By carefully selecting the strength parameter of the ductility element to be less than the tendon strength, the system achieves a transition from elastic-brittle behavior to elastic-plastic ductile behavior, allowing large deformations before failure.
2Adaptability or versatility
If the ductility element deforms under stress to increase ductility, then the deformability of the reinforcement system is improved, but the force required for deformation is reduced compared to the tendon
Solution Approach 1:
The ductility element is designed with specific material and geometric parameters that result in lower deformation force requirements compared to the high strength tendon. By controlling the strength parameter of the ductility element to be less than the tendon strength, the system enables deformation at lower forces, achieving enhanced deformability while maintaining overall structural integrity through the high strength tendon.
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 ductility element enhances the overall ductility of the reinforcement system by deforming at a lower force than the tendon, providing increased deformability and adaptability to mounting variations, thus improving the structural ductility of concrete members.
Implementation Method 1
said weakened deformation zones being deformable and thereby said weakened deformation zones are configured for allowing the length of deformation zones on the ductility element to increase or decrease in an axial direction along the length of said tendon, when the stress on the ductility element exceeds a certain level
Implementation Method 2
The compressible wedge has a smooth exterior tapered surface tapering from a wider end to a narrower end and one or more interior channels for receiving a tendon. The taper angle of the compressible wedge is greater than the taper angle of the bore. Thus, upon insertion of the compressible wedge into the sleeve, the wider end of the compressible wedge forms a wedge contact with the sleeve
Data Source
AI summary
A reinforcement system for anchoring tendons for structural reinforcing a structure such as a concrete structure, said reinforcement system comprises at least one anchor and at least one tendon, said anchor is adapted to fix said tendon in and/or outside said structure, wherein said reinforcement system comprises a ductility element, which is positioned in structural connection between said tendon and said anchor, said ductility element comprising weakened deformation zones being deformable so that the length of the ductility is increased or decreased in an axial direction along the length of said tendon.