I. Product Positioning
This is a cold-swaged connector designed to extend single prestressing steel strands. Classified as an extension accessory for prestressing engineering, it coaxially joins two strands of the same specification to maintain the prestress force transmission path. The gold-colored surface finish is a galvanized anti-rust coating.
II. Structural Analysis
Central Stop/Shoulder: A raised structure in the middle of the sleeve that controls the insertion depth of the strands from both sides. It ensures equal insertion lengths and coaxial alignment, preventing eccentric loading caused by excessive insertion on one side.
Left and Right Sleeve Bodies: Hollow cavities at both ends that receive the strands to be joined. Radial compression using swaging equipment subsequently collapses the sleeve, causing its inner wall to grip the outer wires of the strands and form a rigid, unified assembly.
Strands: Inserted into the sleeve from the left and right ends, using the central stop as a positioning reference.
III. Key Features
1. Structural and Load-Bearing Advantages
Centered Stop Design: The central stop forces a symmetrical arrangement of the two strands, eliminating eccentric loading; this ensures uniform tensile strength across the joint and a higher pass rate for pull-out tests.
Cold-Swaged Connection: Hydraulic compression induces plastic deformation in the sleeve, causing it to tightly grip the multiple wires of the strand. The joint’s anchorage strength approaches that of the base strand material, with minimal slippage.
Integrated Enclosed Structure: The assembly features a smooth, continuous profile after joining, allowing it to be threaded directly into corrugated ducts for subsequent grouting; it is compatible with bonded prestressing systems.
2. Material and Anti-Corrosion Properties
The sleeve is made of high-strength alloy steel with a galvanized and passivated surface finish, offering strong resistance to moisture and rust in construction site environments and suitability for the long-term humid conditions inside ducts.
The sleeve undergoes quench-and-temper heat treatment, ensuring stable plastic deformation during swaging and preventing localized brittle cracking.
3. Construction and Compatibility Features
Individual strand splicing: Designed for extending single steel strands; offers flexible layout options and is suitable for extending prestressing tendons during the segmental construction of box girders and continuous beams.
Simple assembly: Features a central raised collar that serves as a positioning guide, allowing workers to quickly control insertion depth and minimize installation errors caused by human factors.
Compatible with standard equipment: Can be installed using conventional prestressing extrusion machines without the need for custom tooling; suitable for prestressing operations in both highway and railway bridge construction.
4. Application Scenarios
Segmental casting of continuous bridge beams requiring the extension of prestressing tendons;
Extending steel strands for foundation pit anchor cables and long slope anchor cables;
Single-point splicing and reinforcement for prefabricated components where prestressing tendons are insufficient in length.
