Open roof floor slab steel truss floor slab steel load-bearing plate

Advantages

Good mechanical properties: Steel bar trusses provide rigid support, which can reduce the use of temporary supports and can withstand large loads. They are suitable for large-span (3-12m) buildings with heavy loads, such as factories, shopping malls, and warehouses.

High construction efficiency: It can significantly reduce the on-site steel bar binding volume (by 60% - 70%), increase the construction speed, and also meet the requirements of rapid construction of the main steel structure. It can provide a stable working platform in a short time and can adopt the flow construction of laying floor deck slabs on multiple floors and pouring concrete slabs layer by layer.

Environmental protection and energy conservation: By adopting the prefabrication method, it can significantly save construction time and labor costs. During the usage stage, the floor deck serves as the tensile reinforcement for the concrete floor slab, enhancing the rigidity of the floor slab and reducing the consumption of steel bars and concrete.

Key points of construction

Preparations before construction

Technical preparation: Be familiar with construction drawings, understand the design intent and the construction norms and technical standards to be referred to; Conduct technical briefings and pre-job technical training for all operating workers; Prepare the construction organization design in accordance with the requirements of the design documents and construction drawings, and draw up a detailed project schedule.

Material acceptance: Check whether the model of each part of the steel bar truss floor deck is consistent with the drawings, inspect the factory certificate of conformity, and verify whether the appearance quality of the steel bar truss floor deck upon entry, the structural dimensions of the steel bar truss, and the appearance quality of the welding between the steel bar truss and the bottom formwork meet the relevant standard requirements.

On-site condition preparation: This includes rechecking the welding quality and elevation of steel beams, inspecting the embedded parts of shear walls, etc. At the same time, safety passages and protective nets should be set up, and safety and technical briefings for the operation personnel should be completed.

Installation process

Preparations before lifting: Place the reference line for laying the steel truss floor deck on the beam, confirm the completion of the shear wall formwork and steel bar works, prepare simple operation tools, such as soft slings and components for hoisting, labor protection supplies for the operators, etc., provide technical and safety briefings to the operators, and issue operation instructions.

Floor deck lifting: Use on-site tower cranes for loading materials, and adopt belt slings. It is strictly prohibited to directly bind and lift with steel wire ropes to avoid deformation. When lifting, each bundle should be fixed with two steel wire ropes at one quarter of the length of the steel plate at both ends. A test lift should be conducted first to check if the center of gravity is stable and if the soft slings will slide. Only when it is safe and without any concerns can the lifting be carried out.

Floor deck laying: Before laying, mark the reference line for laying the deck according to the starting position shown on the drawing. Align the first deck with the reference line and install the other decks in sequence. The joints between the decks should be tight to ensure no leakage of concrete during pouring. Pay attention to the consistent direction of the laying. The length of the steel truss extending into the upper flange of the steel beam must meet the design requirements. The resting length of the truss plate on the flange of the steel beam should not be less than the larger of 5d (d is the diameter of the lower chord steel of the truss) and 50mm. A 20mm distance should be left at the junction of the two slabs on the upper flange of the beam to facilitate the operation when laying the slabs.

Non-standard plate end: At the end of the span, if the width of the truss plate is less than 600mm, non-standard plates can be used for laying. The non-standard plates should be arranged according to the spacing of the truss reinforcement. If the width of the non-standard plate is less than 180mm, reinforcement with the same diameter as the lower chord reinforcement of the truss should be used for laying.

Welding of plate support ribs to steel beams: Ensure a firm connection.

Check the leakage areas: Deal with any possible leakage problems in a timely manner.

Arrange the distribution bars and additional bars: Arrange them in accordance with the design requirements.

Subsequent construction: After the installation of the floor deck is completed, subsequent construction steps such as stud welding, edge formwork installation, node treatment, and concrete pouring will be carried out. Finally, a quality inspection will be conducted.