The aluminum alloy formwork system has changed the traditional steel pipe and fastener wooden formwork system. It offers accurate forming dimensions, uniform specifications, and convenient connections, reducing the likelihood of deformation, formwork displacement, bulging, grout leakage, root rot, and misalignment. This ensures a structural verticality and flatness qualification rate of over 95%, effectively controlling the geometric dimensions of internal and external corners. The overall assembly of the wall formwork reduces the use of tie rods, improving work efficiency.
1. Main Technical Features
(1) The aluminum alloy formwork is meticulously designed and assembled in the factory according to the construction drawings, using aluminum plates and aluminum alloy profiles. The lightweight aluminum plates provide good stress conditions for the formwork, preventing deformation and skewing, facilitating mechanized and rapid concrete construction.
(2) The aluminum alloy formwork is configured with standard plates plus some non-standard plates, with each non-standard plate numbered. Standard plates for the same components can be mixed, resulting in fast assembly.
(3) The aluminum alloy formwork is easy and quick to assemble and disassemble. The formwork is fixed with standardized pins, making installation convenient. Due to the early removal design of the formwork system, horizontal component formwork can be removed after 36 hours. The formwork is equipped with a multi-level operating platform for easy movement during installation, ensuring the safety of workers during formwork installation and dismantling.
(4) After the aluminum alloy formwork is removed, the concrete surface quality is good, ensuring that the formwork installation is flat and firm, and ensuring that the concrete surface achieves a fair-faced concrete effect.
(5) The aluminum alloy formwork is lightweight, and the formwork design includes material transfer openings for manual transport, facilitating manual upward transport without requiring vertical transportation equipment.
(6) The aluminum alloy formwork has high technical content, strong practicality, and a high turnover rate (theoretically up to 300 times), significantly reducing the cost of engineering formwork and shortening the construction period; it has significant economic and social benefits and broad application prospects. 2. Construction Process
(1) Preliminary Preparation Workflow: Detailed design of aluminum formwork assembly drawings according to the design drawings → Owner, designer, and supervisor review and approval → Aluminum formwork raw material cutting and production → Factory trial assembly of formwork → Owner, designer, and supervisor factory acceptance and adjustment → Factory numbering and packaging for delivery to the construction site → Acceptance of incoming aluminum formwork materials → Handover of construction site and work surface → On-site formwork assembly and acceptance.
(2) Construction Process: Measurement and layout → Wall and column reinforcement binding (wall, column, water and electricity construction) → Wall formwork installation → Beam formwork installation → Floor slab installation → Formwork acceptance → Beam and slab reinforcement binding (wall, column, water and electricity construction) → Reinforcement acceptance → Concrete pouring → Formwork removal → Transfer to the next floor. 3. Key Points of Process Operation
(1) Detailed Design of Template Assembly Drawings: Based on the design drawings, the aluminum alloy supports, templates, and corresponding accessories are drawn in CAD software according to the appropriate scale. The installation process of the aluminum alloy template is simulated. The layout of the support rods and support heads is determined based on the structural load calculation of the template. The feasibility of the entire simulation process is thoroughly studied and analyzed to determine the best construction design scheme that is convenient, fast, and economical.
Detailed design must be carried out under the condition that the following drawings or matters are clearly defined:
1) Architectural and structural drawings issued by the design institute;
2) External scaffolding plan, floor layout of cantilevered I-beams, and I-beam plan positioning diagram;
3) Surveying and layout plan, indicating the location of surveying and layout holes;
4) Concrete construction plan, the location of concrete pump pipes needs to be clearly marked on the plan;
5) Mechanical and electrical design drawings, determining the location of water and electricity pre-embedded parts and openings. (2) Trial Assembly of Formwork in the Factory: 1) Conduct trial assembly in the aluminum formwork processing plant. After assembly, measure the flatness and verticality of beams, slabs, walls, and columns to ensure they meet the specifications after leveling. 2) After trial assembly, check the axial distance and cross-sectional dimensions of different aluminum formwork units. If these indicators have an error greater than ±2mm, the quality of on-site assembly of aluminum formwork will be difficult to control. For aluminum formwork exceeding the above standards, unqualified components must be replaced before it can be used in the formal project. 3) Check whether the trial assembly of aluminum formwork matches the architectural drawings, especially some wall details. 4) Check whether the openings requiring structural openings are equipped with formwork. 5) According to the external scaffolding construction plan, check whether the reserved plates for openings in the cantilevered I-beams are in place. 6) Check that the support system of the aluminum formwork meets the requirements. 7) Check the dimensions of the back ribs and aluminum... 8) Check whether the dimensions of the formwork and the number of rows of back ribs are reasonable and consistent with the detailed design drawings;
9) Check whether the aluminum formwork is deformed, whether the numbering follows the systematic numbering, and whether it is easy for workers to identify;
10) Check whether the positions of the measurement and layout holes, concrete pump pipe holes, and aluminum formwork material transfer ports are correct and reasonable;
11) Check whether special color markings are used for aluminum formwork that requires positioning for water and electricity, so as to facilitate identification;
(3) On-site pre-installation inspection
1) Check the formwork, supports, and miscellaneous components delivered to the site one by one according to the material list, and check whether all accessories are complete;
2) Check whether the water and electricity pre-embedded on the wall columns of the installation floor has been completed.
(4) Measurement and layout: Mark the wall column lines and wall column control lines, and opening lines on the floor. The wall column control lines are 300mm away from the wall edge line, which can be used to check whether the formwork is misaligned and square; mark the floor elevation control points on the column longitudinal reinforcement. The elevation control points are floor +0.50m. They are set at the four corners and corners of the wall columns to check the floor elevation. Precision control should be within 3mm. Installation workers must verify the alignment before installing the wall and column formwork (because aluminum alloy formwork is a standardized formwork; if individual parts deviate, it will cause overall deviation).
(5) Installation of wall and column reinforcement (wall and column water and electricity pre-embedded): Strictly control the deviation of the reinforcement. Weld the wall and column positioning reinforcement according to the alignment (adjust the wall and column reinforcement in a timely manner during concrete pouring). The wall and column reinforcement should be installed promptly, and water and electricity construction should be accurate and timely, generally within 5 hours.
(6) Installation of wall and column formwork:
1) Before installing the wall and column aluminum formwork, check whether the floor slab elevation at the wall and column position meets the requirements according to the elevation control points. Remove the surface concrete laitance if it is too high, and place wooden wedges if it is too low, trying to control it within 5mm.
2) Weld positioning reinforcement to the longitudinal reinforcement at the base of the wall and column to prevent the aluminum formwork from shifting during reinforcement; install cement inner supports or steel inner supports of the same thickness as the wall and column inside the wall and column to ensure the cross-sectional dimensions of the wall and column after reinforcement. 3) Before assembling the aluminum formwork for walls and columns, the inner surfaces of the formwork must be thoroughly cleaned and coated with a release agent. The release agent should be applied thinly and evenly, without any missed areas. During application, pay attention to the surrounding environment to prevent it from spilling onto the building, machinery, or clothing, and especially avoid applying it to the reinforcing steel. (Use Weiye brand aluminum alloy formwork-specific release agent; this agent is weakly alkaline. Use an oil-based release agent for the first three floors and a water-based release agent for subsequent floors.)
4) Assemble the aluminum formwork for walls and columns according to the order shown in the trial assembly drawings. Before sealing the column formwork, pre-insert PVC pipes onto the fastening bolts of the wall and column formwork, with rubber cups attached to both ends of the PVC pipes. Ensure that the pipes are accurately positioned against the formwork surfaces on both sides of the wall so that the tie rods can be retracted after pouring.
5) To prevent grout leakage at the bottom of the aluminum formwork for walls and columns, seal it with cement mortar the day before pouring concrete. Do not use cement bags to seal the bottom of the formwork, as this can cause "root rot." 6) When installing exterior wall formwork, it should be dismantled and then uploaded and installed simultaneously (i.e., while dismantling the next layer of formwork, workers on the scaffolding pass the dismantled formwork upwards through the distance between the scaffolding and the wall; after receiving the formwork and applying release agent, the workers on the operating floor directly install the formwork according to the lines and ensure it is securely fixed. Do not lean the formwork against the tied wall and column reinforcement bars, as this will cause deformation of the reinforcement bars and prevent the concrete cover from being too large or too small after pouring).
(7) After the wall and column formwork is installed and verified, the beam and slab formwork is installed. Based on the beam's position and span, install the beam bottom formwork and formwork support poles according to the design drawings. Specific operational points are as follows: Support the beam bottom formwork on the beam notch reserved in the column formwork; install the beam bottom support poles along with the bottom formwork, ensuring reliable connection. Adjust the beam bottom plate elevation according to the design by adjusting the pole support elevation, then install the beam side formwork and correct the verticality of the side formwork. Simultaneously install the corner formwork between the wall columns and the slab. After the corner formwork is installed, install the slab beams, slab formwork, and supporting uprights. After installation, use a level to check the flatness of the beam and slab formwork again. Adjust the bottom supports of the uprights to ensure the formwork is within the allowable level. The connections between the bottom formwork of the beams and between the bottom formwork and the side formwork should also be bolted to prevent bulging.