Cold Normalized Reinforcing Bar Ends for Residual Deformation
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Solution Overview
Problem
Existing methods for connecting reinforcing bars in reinforced concrete structures are prone to residual deformation under mechanical stress, leading to potential cracks or collapse, and require oversized bars to mitigate this risk, increasing costs.
Innovation Solution
A process involving cold upsetting and normalization of the reinforcing bar's end portion with hooking asperities and threading, where mechanical stresses are applied below the elastic limit to reduce deformation and enhance adhesion, using a normalization machine to exert controlled stresses and detect defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the reinforcing bar is oversized to avoid residual deformation, then the reliability is improved, but the cost increases significantly
Solution Approach 1:
The patent applies cold normalization treatment to change the physical state and microstructure of the reinforcing bar end portion, transforming the material parameters to eliminate residual stresses and prevent deformation, thereby avoiding the need to increase bar size or cost
Solution Approach 2:
The cold normalization treatment is performed in advance during manufacturing, before the reinforcing bar is installed and subjected to mechanical stresses. This preliminary action eliminates potential deformation risks before they can occur during service
2Reliability
If cold normalization is applied to eliminate stresses, then the reliability is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent replaces complex thermal normalization processes with a simpler cold mechanical normalization process, using controlled mechanical stresses instead of heat treatment to achieve the same stress elimination effect, thereby simplifying the manufacturing process
Solution Approach 2:
The cold normalization process utilizes the material's own elastic properties and phase characteristics at room temperature to achieve stress elimination, without requiring external heating equipment or complex process control systems
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 process significantly reduces the risk of residual deformation, ensures secure connections between reinforcing bars, and simplifies the manufacturing process, making it more economical while maintaining optimal performance under normal and extreme conditions.
Implementation Method 1
an upsetting step of cold upsetting the end portion in an upsetting direction which is substantially parallel to an extension direction of the reinforcing bar
Implementation Method 2
The upsetting step consists of exerting cold mechanical stresses on the end portion in the upsetting direction
Implementation Method 3
the normalization step consists of exerting cold mechanical stresses on the upset end portion in a stress direction which is substantially parallel to the upsetting direction and in a second stress direction which is opposite to the first stress direction
Implementation Method 4
Such a normalization step makes it possible to eliminate the stresses that appeared in the end portion upset during the upsetting step and therefore to homogenize the crystalline structure
Implementation Method 5
an extension portion provided with gripping roughnesses
Implementation Method 6
a first and a second reinforcing bar each comprising an extension portion provided with gripping roughnesses
Data Source
Figure 1~2
Figure 3
AI summary
Method for preparing a reinforcing rod for reinforced concrete Method for preparing a reinforcing rod (2) for reinforced concrete comprising a providing step comprising providing a reinforcing rod (2) comprising an extension portion (3) including, on the outer surface thereof, catching asperities (6, 7), and an end portion; an upsetting step comprising cold upsetting the end portion in an upset direction which is substantially parallel to an extending direction of the reinforcing rod (2); a threading step comprising providing a thread (8) on the upset end portion (4); and a normalisation step comprising cold normalising the upset end portion (4).