Resistive Coating for PC Anchorage Corrosion Isolation
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Solution Overview
Problem
Tendons in prestressed concrete structures, such as PC steel strands or PC steel bars, are prone to corrosion when moisture enters between the tendon and the anchorage, particularly in environments like near the sea or heavy snowfall areas, due to potential differences leading to electric current flow and corrosion.
Innovation Solution
An anchorage system with a coating film having an electrical resistivity of 10^4 Ω·m or more is applied on the contact surfaces between the tendon and the anchorage, minimizing electric current flow and thus reducing corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a coating film is provided on the contact portion of the anchorage surface, then corrosion resistance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies parameter changes by specifying the electrical resistivity of the coating film must be 10^4 Ω·m or more. This quantitative parameter control ensures the coating provides sufficient electrical insulation to prevent corrosion while maintaining a relatively simple manufacturing process. The coating material and thickness are optimized to achieve the required resistivity threshold.
Solution Approach 2:
The coating film is applied selectively to the contact portion of the anchorage surface where the tendon makes contact. This localized application provides corrosion protection precisely where it is needed most, rather than coating the entire anchorage component. The contact portion is identified as the critical area requiring protection against electrochemical corrosion.
2Duration of action of stationary object
If the coating film thickness is increased to improve corrosion protection, then durability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies that the coating film thickness should be 50 μm or more but 5 mm or less. This parameter range optimization balances durability with manufacturing feasibility. The lower limit of 50 μm ensures sufficient corrosion protection and electrical insulation, while the upper limit of 5 mm maintains manufacturing practicality and avoids excessive complexity in application and curing processes.
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 anchorage system effectively prevents corrosion between the tendon and the anchorage, enhancing the durability of the prestressed concrete structure by maintaining the integrity of the tendon and anchorage components.
Implementation Method 1
The coating film has an electrical resistivity of 10^4 Ω·m or more
Data Source
AI summary
An anchorage for gripping and fixing an end portion of a tendon is provided. The anchorage includes a base having a surface; and a coating film provided at least on a contact portion of the surface of the base. The contact portion contacts the tendon when the tendon is gripped by the anchorage. The coating film has an electrical resistivity of 104 Ω·m or more.