Socket-and-Tongue Keyway Scaffolding Technology
Jul 07, 2026| 01 Overview of Key Technologies
1. Features of the Scaffolding System
1) The socket-type keyway scaffolding system is characterized by joints and vertical poles cast as a single unit, with an optimized design for the scaffolding connection joints. The poles and couplers are integrated into a single unit, creating a scaffolding system that is quick and easy to assemble and disassemble.
2) The keyway joint connection uses a plug-and-socket design and incorporates gravity-activated wedge-type pins. This allows for visual confirmation of whether the pins are self-locking, and as the scaffold sways, the gravity-activated pins tighten further. Additionally, the horizontal connections and constraints in all four directions enhance the overall stability of the support system.
3) The top horizontal beam directly replaces the secondary purlin, saving materials and promoting environmental sustainability. The scaffold's tapered top pole connects to the top horizontal beam without the need for couplers or the free-end restrictions found in bowl-coupler scaffolding. Load-bearing poles are used at the bottom of beams, eliminating the need for vertical poles beneath standard-sized beams and reducing the amount of steel pipe required for the scaffold.
4) This support system is simple and quick to operate, significantly improving scaffolding construction efficiency, reducing workers' physical strain, and minimizing labor requirements.
2.Technical Specifications of the Scaffolding System:
The standard technical specifications for this scaffolding system are as follows: the longitudinal spacing and row spacing of the vertical posts are 900 mm or 1,200 mm, and the bay spacing is 1,500 mm or 1,200 mm. The top bay spacing is adjusted using adjustable tapered top posts based on the floor-to-floor height. The manufacturer can also custom-manufacture corresponding specifications based on the actual layout requirements calculated for the project.
There are currently no national or industry standards or codes governing this formwork system. Based on the various structural performance tests conducted by the manufacturer, calculations for this formwork system may be performed in accordance with JGJ231-2010, "Technical Safety Code for Socket-Type Disk-Coupling Steel Pipe Scaffolding in Building Construction."
02 Construction Process
Piping → Scaffolding Layout → Layout Marking → Erecting the First Course of Uprights and Horizontal Members → Erecting the Second Course of Uprights and Horizontal Members → Erecting Brace Heads → Formwork Installation
03 Key Construction Procedures
(1) Pipe layout: Calculate the scaffolding layout based on standard scaffold specifications (verification may be performed in accordance with the Safety and Technical Specifications for Coupler-Type Scaffolding); proceed with pipe installation only after requirements are met.
(2) Scaffolding Layout: Plan the scaffolding erection positions based on the locations of beams, slabs, and columns.
(3) Layout Marking: Since socket-type scaffolding has extremely strict tolerance requirements, on-site construction must strictly follow the formwork layout drawings when marking out lines. The next construction step may only proceed after the layout has been inspected and approved.
(4) First Course of Uprights: Place shims according to the construction lines, ensuring they are of the same material and height as much as possible. Position the first course of uprights on the shims, and select horizontal crossbars of the appropriate length (0.9 m or 1.2 m standard bars) from the standard-floor formwork layout diagram to serve as the first-level crossbars, connecting them to the second-level crossbars.
(5) Insert the second row of vertical posts into the top of the first row. Then, install the third horizontal crossbar and set up load-bearing posts beneath the beams. For frame beams measuring 300 × 600 or smaller, the load-bearing posts can directly support the load. For frame beams larger than 300 × 600, additional support posts and connecting components must be installed at the bottom of the beams; the number of additional posts is determined by calculation.
