Magnets and magnetic formwork for ferroconcrete items: description and configuration features
Magnetic formwork is a collapsible structure made of certain elements, designed for fixing the formwork borders to the molding table with the help of permanent high-powered magnetic blocks in ferroconcrete items production. Such designs allow manufacture of flat concrete products up to 600 mm height of the required geometrical sizes including radial state at plant or manufacture site conditions.
The main components of the magnetic formwork complex are:
- Permanent magnet block (formwork magnet)
- Adapter for fastening the shuttering board
- Stiffening rib (C-profile)
- Formwork plate (plywood, metal)
- Fasteners (tie-bars, cap screws, nut rings)
Depending on the complexity of the manufactured products, additional elements based on magnets can be used (embedded items, loopers, blockouts, chamfers, rust formers, junction box fasteners…)
Where is magnetic formwork used and how is it profitable
Magnetic blocks and fasteners system are used at manufacturing enterprises producing ferroconcrete items: paving and road slabs, support blocks and lintels, ferroconcrete runs, fences, steps, sleepers, pillars, injection and free-flow pipes, etc.
The use of magnetic formwork makes it possible to reduce utilizable and expensive resources, i.e. time and employees. According to customer responses, the work is performed two or three times faster, in comparison with other types of formwork systems.
Additionally, compactability, ergonomics, low weight, ease of installation / uninstallation, multifunctionality, durability, reliability and strength of magnetic formwork were evaluated by enterprises using such a system.
Technical characteristics that you should pay attention to when buying magnetic formwork in Ukraine
Magnetic formwork system is produced taking into account the conditions of its operation and is designed for a long period of use. Parts and components of the system are made of durable materials that are resistant to various temperatures, humidity, contamination, mechanical damage and high loads. However, each enterprise has different tasks; therefore it is necessary to choose equipment according to the technical characteristics:
- Blocks with magnets. When choosing, dimensions, clamping force and axle base are taken into account. There are standard sizes on sale, but you can order production according to any parameters. The pullout force reaches 2,400 kg.
- Fasteners. There are single, double-sided and angular fasteners. Can be installed into the system by using cap screws and special clamps. Fixing poles and adaptors vary in height and weight.
- Magnet borders vary in length, height and sectional view. Depending on the type of working surface of the border, it is possible to form a groove, ridge or chamfer on the edge of the ferroconcrete product. This design may have a mechanism for attaching to the molding table (internal or external), retractable rails, hinges / handles for strapping and other details.
- Elements forming openings are designed to form fabrication holes and slots in ferroconcrete products. When installing them, magnetic boxes and washers are used – these elements ensure installation accuracy and reliability of fixation. Important characteristics of elements forming openings include: mechanical or manual installation, the availability of formwork grades, sealing, gripping devices. These products can be of various sizes and configurations (jointed, prefabricated).
- Chamfers, loopers and washers are used to form holes in ferroconcrete products. They differ in shape, size, weight, value of the separation force, equipped with an integrated magnetic system.
How to calculate the required number of magnets for formwork
It is important to understand the fact that magnets can lose their characteristics under certain conditions. Therefore if the required number of boxes is known (from the project), yet the environmental conditions (or excessive system load) can reduce operational characteristics of the system, the project should be further developed.
Take into account length and height of the structure as well as the clamping force, the axle base of the blocks, possible mechanical impact on the formwork (vibration, mixture shrinkage); it is possible to independently determine the number of required magnetic boxes.
Features of assembling the magnetic framework
Magnetic formwork is a system that is predesigned. Depending on the type of manufactured products, the necessary components are selected.
Threaded holes are located on the magnetic boxes, allowing you to attach it to the bracket/ adapter on the one side, and to the board/ molding table on the other. There is a special button on this box, which brings the system to working position by pressing it. To deactivate the button it is reset to its original position. It is important to consider that special tools, such as a rubber hammer and a tear-off device, are used to activate / deactivate the magnetic box.
After the formwork is defined, the mold with concrete mixture is poured and the openings or magnetic embedded items are installed (if necessary). When the product completely hardens, the system components are removed.
The advantages of magnetic formwork in comparison to other types of similar configurations
The use of magnetic formwork can improve the productivity and income of any ferroconcrete products manufacturing enterprise, since this configuration is characterized by:
- Variability. With its help, it is possible to produce a batch of products of any shape and size, and, therefore, implement any non-standard project.
- Convenience. Assembly and disassembly of the system does not require special efforts, skills and time. When changing tasks, the magnetic formwork system can be easily and quickly disassembled.
- Low cost. When using blocks with magnets, it is not necessary to clean the molding table with a grinder, work with a welding machine, and systematically repair expensive equipment.
- Size precision of the final products. Due to the secure fixation, produced ferroconcrete structures have strictly specified size and shape.
In addition, using magnetic formwork, the company significantly saves on the maintenance of such a system, minimizes the time spent by employees on installation / uninstallation and increases productivity / income.
Magnetic formwork exploitation period
Magnetic formworks are made taking into account the conditions in which they will be used. However, the rules of use and storage violation, lack of maintenance and other reasons can lead to functional loss of the equipment. The exploitation period is affected by:
- Quality of the raw material which the system components were made of.
- Qualification of the specialist who developed the project and performed all the calculations.
- Compliance with the manufacturer’s recommendations regarding storage, installation and use conditions.
- Level and frequency of loading.
- Quality and systematic maintenance (cleaning, greasing, etc.).
In general, while meeting the requirements specified in the service instructions, the magnetic formwork does not change its mechanical characteristics for a long time.
More details about magnetic formwork (shuttering systems)