In this article, we will look at the various types of steel formwork on the market, such as slip formwork and fixed formwork, each of which serves its purpose and has its own advantages. We will then focus on why steel formwork is superior to other materials, the steps in the steel formwork process, and advice to maximize its use and life expectancy.

Types Of Steel Formwork

Commonly, steel formwork (metal shuttering) can be classified into two types, slip formwork and easy formwork, which are two forms that have distinctive functionality in varying construction conditions.

1. Slip Steel Formwork

      Slip formwork is an unusual type of formwork that is constantly relocated upward or downward as concrete. Rather than constructing multiple levels of formwork in taller structures, it allows for the creation of continuous, elevated structures, such as high-rise buildings, silos, and chimneys. Slip-formwork structures are almost always internally braced and supported by hydraulic jacks or guide columns for smooth, consistent movement in a continuous upward or downward motion for construction.

      The slip-formwork construction method is very favorable where continuous concrete walls are desired because there are no construction joints to worry about, thus lessening concerns of structural weak points. Slip steel formwork designs are also considered time-effective because they speed up construction time, which can be particularly advantageous with taller structures requiring multiple set ups of traditional formwork information.

Different Types Of Slip Formwork

There exist six categories of slip formworks, which differ based on the construction direction:

■ Vertical slip formworks - the slip formwork is intended for slip formworking vertical infrastructure; the workers work on a working platform to place the reinforcement on a working platform and keep a smooth concrete pour. The concrete slip formwork and working platform rises vertically through a system of hydraulic jacks.

■ Horizontal slip formworks - the slip steel formwork is for slip formworking pavements, traffic barriers, etc.; a hydraulic jack allows the concrete to be laid, vibrated, processed, and locked in place; while a hydraulic jack slowly advances the slip formwork during the concrete placement process.

■ Conical slip formworks - the slip formwork is used to slip formwork tall structures such as conical chimneys, cooling towers, and piers; the slip formwork slips gradually through either using a working platform or method; the overlapping acceptance of the slip formwork allows for varitions in dimensions of the wall and diameter; in using for architectural concrete, the joints are obviously apparent so not recommended.

■ Cantilever slip formworks - slip formwork independent of the crane, which is for self-lifting large area formwork systems; it can be used for walls, columns, floor supports, and transitioning when the area changes in dimension.

■ Egg slip formworks - generally used based on the principles of jump molds; able to change axis and vertical circumferential slope to adapt to any geometry.

■ Conical slip formworks - the slipconstructed from cantilever plates and overlapping plates; self-leveling aspect of the can easily accommodate wide and varying taper and wall thickness at the same time; fixed on a steel bracket.

Notable Uses:

• High-rise buildings.
• Silos and storage towers.
• Chimneys and cooling towers.

2. Fixed Steel Formwork

      Fixed formwork is another widely used steel formwork system, used to form and support concrete until it has cured and gained enough strength to support itself. Unlike slip formwork, fixed formwork is placed at a specific location and remains there during the curing process. Fixed formwork is a more versatile formwork system and is used for various other types of concrete structures.

Fixed formwork is divided into two general systems:

2.1 Large-size Steel Formwork

      Large-size formwork is authorized for pouring large concrete surfaces, including walls and slabs with large surface areas. Large size formwork systems are mostly prefabricated and in a single pour, can cover a large surface area, which decreases construction time and work and aesthetics.

Large-size formwork systems are prevalent in large structure applications such as office buildings, commercial buildings, or industrial buildings where consistency and time reduction is critical.

Key Application areas include:

• Large area walls
• Steel formwork for slab
• Large-scale building applications

2.2 Small-size Steel Formwork  

      Small-size formwork is adaptable and allows for the production of smaller, more detailed formwork elements such as columns, beams, and stairs. Owing to its multi-faceted nature, small-size formwork is suited to work with complex geometries and irregular shapes when giving a precise shape to reinforced concrete.

Small-size formwork is highly capable in detail work is compact space where larger formwork would be heavy and impractical. For this reason, small-size formwork is very popular for residential and commercial construction.

Specific Applications:

• Columns and beams.  
• Stairs and landings.  
• Irregular or complex structural components.

3.Column Steel Formwork

• Description: This type is specifically designed for casting concrete columns. It consists of cylindrical or square steel panels that create a solid mold around the column. Adjustable bolts make it easy to modify the dimensions according to column height and thickness.
• Advantages: Provides high accuracy and smooth finishes for columns. Its reusability lowers the cost per use, and it’s easy to assemble and dismantle.
• Best Applications: Used primarily in high-rise structures, commercial buildings, and any project requiring multiple columns with consistent shapes and dimensions.

4. Steel Tunnel Formwork

• Description: Steel tunnel formwork combines horizontal and vertical panels to create a tunnel shape, allowing walls and slabs to be cast in one operation. This formwork speeds up construction and improves structural consistency.
• Advantages: Significantly reduces construction time and increases efficiency. The steel structure is durable and highly reusable, and the tunnel shape enhances the strength of the concrete.
• Best Applications: Often used in mass housing projects and repetitive projects where speed and uniformity are priorities.

5. Steel Circular Formwork

• Description: Steel circular formwork is a specialized type used to cast round shapes, such as circular columns or curved walls. The panels come in curved sections that are assembled to form the desired radius.
• Advantages: Provides consistent and smooth finishes for circular or curved shapes, with strong resistance to deformation under pressure.
• Best Applications: Widely used for circular columns in bridges, high-rise structures, and architectural features with curved elements.

The Benefits Associated With Steel Formwork Systems

The first use of concrete formwork is steel formwork to create concrete, providing some benefit.

• Strength and Durability: steel fomrwork are infinitely stronger and much more durable than wood. This means they can sustain harsher environmental factors and carry more weight without bending or breaking. Also, steel fomrwork yield true, even and uniform forms for concrete.

• Precision and Finish Quality: steel fomrwork yield a smooth surface finish, creating for much greater precision with less imperfections, and therefore yield a better quality product for more complex design features.

• Reusable and Economical: steel fomrwork are a reusable product and can be reused many cycles, provided they are returned to their original sturdiness. This makes steel fomrwork a much better long-term value than the equivalent traditional construction materials, such as wood.

• Flexibility: steel fomrwork can be re-altered and formed into many different size and shape configurations for many varied types of construction applications. Available in both simple pour forms to complex form work.

• Sustainability Considerations: steel fomrwork construction are reusable and infinitely recyclable. steel fomrwork reduce material waste, a standard byproduct of traditional construction, for material waste in construction is drastically reduced.

Steel Formwork Application Procedure

The procedure for applying steel formwork occurs through the following:

• Design and Planning: Design and planning is vital to make sure the formwork system suits the definition of the project, allows for tolerances, and the work is aligned.

• Installation: The formwork system is installed and aligned to prevent any movement while the concrete is being placed as well as bolted/ restrained.

• Pour and Cure Concrete: Concrete is placed and poured into the system and formed, and then must cure in order to allow the concrete to set - and strengthen.

• Removal of Formwork: After curing, the formed structure is reapplied to the work site. Finally, the formwork system should be cleaned and inspected in order to function for the future.

Steel Formwork Care and Maintenance

The steel formwork care and maintenance includes the following processes, to ensure extended life and performance of the system:

Regular inspections of the components:

• Inspecting the system prior to use: prior to the application, system should be inspected for signs of damage, wear, denting, rust, misalignment, etc.  It is also wise to inspect supports and all connections.   
• Inspecting the supports during use: while under load, inspection of system supports to confirm the system is functioning as intended in regards to deformation can be good. Does a steel support component appear deformed or shrunk?
• Inspecting the supports post use: Once the forming system is disassembled, inspections can confirm evidence of past, or present problems: This is also a good time to document and repair the problems.  

Formwork Cleanup and Storage:

• Cleanup: After the formwork has been erected or installed, it is critical and important to clean concrete residue off the face of the formwork without delay, to avoid hardening, which can damage the formwork face. Use safe cleaning methods only, and do not use aggressive cleaning or solvent cleaning processes.
• Storage: Formwork should be stored uncovered, in a clean and dry location that limits moisture or exposure to the outside environment. Formwork should be stored in stacks to prevent warpage and damage to formwork components. Stacks should be organized, marked, and labeled for easy access and tracking.  

Repair and Replacement:

• Perform minor repairs: If you are going to perform a minor repair you will take the appropriate tools to accomplish the repair for smaller issues whether that be a dent or a bent bracket. For a crack, you will weld the crack to restore the integrity and you will replace any fastener that fails.
• Perform major repairs: If the damage or corrosion is such a significant issue that requires a large repair then it is best to consult a qualified repair profession that will be able to determine the costs on repairing the replaceable part or if it is wiser to replace the damage. If replacement of parts is warranted to maximize safety and functionality of equipment, then places any replaceable parts.

Conclusion

      Steel formwork, selected for construction today, has strength, accuracy and flexibility built-in. This blog post indicated various types of steel formwork you would see today, especially siding and fixed formwork and their various features such as durability, reuse and flexibility.

      If you want to work with steel formwork, the process should be planned out well in advance, from design, to installation, pouring the concrete, to removal. With proper maintenance and care (and repairs when needed) the material has the ability provide durable, long lasting service.

      The merits of being aware of and thinking about these principles will give the construction professional a more efficient approach, and as a result a higher quality product. Steel formwork contributed strength to a concrete structure as well as contributed to more sustainable modern construction principles. 

FAQ

Is Steel Formwork Better Than Wood Formwork?

• Steel formwork is better than wood formwork because it offers greater durability, reusability, and precision, making it more cost-effective in the long term.

How Many Times Can Steel Formwork Be Reused?

• Steel formwork can typically be reused from 7 to around 50 times, depending on the quality and maintenance.

What Are The Types Of Reusable Formwork?

• The types of reusable formwork include steel, aluminum, plastic, and fiberglass formwork.

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