In China, the technology of steel frame structure coupling sleeves has made rapid progress through the introduction of professional techniques and the diligent efforts of research institutions’ experts. The development of this technology has gone through several stages, such as hot forging of the sleeve specifications, tapered external threads, upsetting and extrusion forming. With the continuous improvement of the technology, the cost of sleeves also been reduced. Following we will discuss how to install steel reinforcement coupling sleeves and the key points to note.

Installation of steel reinforcement coupling sleeves and washers:

1. According to the provisions of the seismic design level, coupling sleeves washer should avoid installing the coupling heads in the end regions of the structure and the regions with increased reinforcement density at column ends. If it is necessary to install in locations with high internal stress, the percentage of Level 3 coupling heads within the same connecting section should not exceed 25%, Level 2 should not exceed 50%, and there are no limitations for Level 1.

2. Avoid the end regions of the structure and the regions with increased reinforcement density at column ends as specified by the seismic design level. Choose Level 1 or Level 2 coupling heads for installation. If it is unavoidable, the percentage of coupling heads should not exceed 50%.

3. There are no limitations on the percentage of coupling heads installed in positions where the internal stress of the building’s steel reinforcement is small or in vertically loaded steel reinforcements.

4. For prefabricated components that instantly bear driving force load, the percentage of coupling heads should not exceed 50%.