Feicui Jun Aluminium Concrete Formwork Scheme

● Structure Overview

The main specifications of concrete formwork components for this project are listed in the table below.

The concrete strength grade is as follows:

● Aluminium concrete formwork details optimization

Buildings 3, 5, and 6 in the Feicui Jun project have a floor height of 3 meters. The structural design mainly consists of shear walls, with no complex nodes on the periphery except for one node variation on the 26th floor. In order to achieve a plaster-free effect on the exterior walls, the aluminium concrete formwork details have been optimized during the refinement process by considering the concrete formwork diagram.

1. To achieve a plaster-free exterior wall, all masonry on the outer walls, including window partition walls, window sills, and lintels, are being replaced with cast-in-place structures. The reinforced concrete walls have a reinforcement layout of 8 bars at 200mm spacing, with one set of horizontal and vertical reinforcement on each side of the wall.

2. The door jambs (with a length of ≤250mm) connected to the shear walls will be replaced with cast-in-place concrete structures. Slots will be reserved at the junction between shear walls or beams and brick walls to prevent cracking of the plaster layer caused by drying shrinkage of autoclaved aerated concrete blocks. A 10×150mm groove will be used, and for a small portion of beams with a height of 400mm, a 10×100mm groove will be employed.

3. Window opening construction:
1). For regular 50 series windows, a 50mm×10mm groove will be reserved. For 90 series windows, a 40mm×10mm groove will be reserved. Both the interior and exterior sides will have the pull-tab groove, with the distance between the pull-tab groove and corners not exceeding 200mm, and evenly spaced intervals not exceeding 450mm. On the exterior side of the window frame, the rebate groove extends along the width of the wall to the edge, with a width of 60mm.
2). On the interior side of the window frame, the pull-tab groove extends along the width of the wall to a distance of 10mm from the edge, with a width of 60mm. The depth of the groove is uniformly set at 6mm. Considering the internal insulation thickness, regular external window frames will be installed in the center.
3). The dimensions of the exterior door and window openings will be determined based on the installation instructions for doors and windows, taking into account a 25mm installation gap. For interior door and window openings, after the plastering is completed, the dimensions will be based on the door and window drawings, without considering the installation gap.
4. Standard floors will be constructed using aluminium concrete formwork, while non-standard floors will be determined through negotiations between the main contractor and the construction unit, either using timber formwork for concrete walls or concrete formwork moulds.

● Aluminium concrete formwork design

★ Aluminium concrete wall formwork systems
1. The wall columns of the project are built with standardized 6061-T6 aluminium concrete formwork and arranged one by one using aluminium concrete formwork wall sections that have a width of 400mm.
2. concrete formwork wall is composed of three pieces, net height (layer height - board thickness) = internal corner formwork + concrete formwork wall + bottom corner aluminium (40mm) + pre-fastening size (10mm).
3. The concrete formwork wall is connected using concrete formwork wall ties and reinforced with concrete formwork waler. There are four concrete formwork waler installed on the interior walls, while five concrete formwork waler are installed on the exterior walls.
4. The k-form concrete formwork is used to connect the upper and lower floors, and once installed, it protrudes 50mm above the structural surface.
★ Aluminium concrete formwork beam system
The aluminium concrete formwork beam system includes side aluminium concrete formwork beam, bottom aluminium concrete formwork beam, and concrete formwork supports installed under the beam.
★ Aluminium concrete slab formwork systems
Concrete slab formwork systems consist of house concrete slab formwork, floor keel, and concrete formwork supports. Independent steel supports are used with a spacing of 1200mm × 1200mm.

1. The length of house concrete slab formwork is 1100mm.
2. The standard component for corner sections of house concrete slab formwork is 400mm.
3. A single support is installed at the ends, while double supports are installed in the middle.

★Aluminium concrete formwork supports system
The aluminium concrete formwork supports system uses Q235B steel pipes with welded steel plates at the bottom. Concrete formwork steel stakes are used for supporting the beams at the bottom, with a maximum spacing of 1200mm.

★Aluminium concrete formwork accessories system
Aluminium concrete formwork accessories systems include concrete formwork brackets, concrete formwork spacers, concrete formwork waler, concrete formwork tie rods, concrete formwork bolts, concrete formwork pins, etc.

The aluminium concrete formwork is connected using concrete formwork accessories and reinforced with concrete formwork tie rods. The horizontal spacing between them is equal to or less than 800mm, while the spacing in special positions depends on the actual structure of the building. The concrete formwork waler is made by welding two rectangular steel pipes with dimensions of 60402mm. Reinforcement blocks are welded in the middle. Floor heights of 2#, 3#, 5# and 6# are all 3 meters. For the interior walls, four concrete formwork waler are installed, and an additional vertical concrete formwork waler is added at the push pull props. The exterior walls are reinforced with five concrete formwork waler. The distances between each concrete formwork waler on both the interior and exterior walls are 290mm, 600mm, 600mm, 700mm, and 610mm from the floor, forming a stable hollow metal frame structure. The overall integrity is high, resulting in good quality after pouring and forming.

★ push pull prop system
The push-pull prop system is designed to achieve triangular adjustment, ensuring the verticality and flatness of vertical members (walls, columns), while enhancing their horizontal stiffness and load-bearing capacity to resist fresh concrete pressure on formwork.

● Construction deployment

★Aluminium concrete formwork configuration quantity

★Division of flow sections
Buildings 3, 5, and 6 have identical layouts and can start construction simultaneously. The construction will be organized into three installation teams for stratified construction. Each building does not have expansion joints and features symmetrical left and right structures with no complex nodes. For the exterior wall lines on the 26th floor, different concrete formwork types will be used for construction.

The non-standard floors (bottom 1-3 floors and the roof) will be constructed using timber formwork for concrete slab, while the rest of the floors will be constructed using aluminium concrete formwork construction. The reasonable division of concrete formwork le construction is a prerequisite for ensuring project progress, construction quality, and efficient on-site organization management. By dividing the construction process into reasonable stages, uninterrupted workflow of laborers from different professions (such as steel workers, concrete workers, formwork workers, and scaffold workers), as well as proper supply of materials (such as steel bars, concrete, and formworks) and efficient use of mechanical equipment (such as tower cranes) can be guaranteed.

★ Labor Force Requirement Plan
Buildings 3#, 5#, and 6# are constructed by 3 installation teams. Based on the area covered by aluminium concrete formwork, the following table outlines the required number of personnel: