Wall formwork

Types of wall formwork

Wall formwork is a temporary structure that supports walls during the construction of a building. It holds wet concrete in place until the concrete sets and hardens into the desired wall shape. Wall formwork is reusable and made of different materials, such as plywood, steel, and aluminum. Here are the types of wall formwork:

• Traditional Wall Formwork

  Traditional wall formwork consists of vertical and horizontal beams. The beams are also known as formwork props and are supported by a rectangular grid of wooden or metal beams. The grid construction is what holds the concrete walls in place. Traditional wall formwork is popular because it is cost-effective and can be adapted to different wall sizes. However, it requires skilled labor to assemble and disassemble it. It is also time-consuming and not suitable for large-scale construction.

• Pneumatic Wall Formwork

  Pneumatic wall formwork is an air-pressure-operated system. Air pressure inflates the formwork, creating a cavity where concrete can be poured to form walls. Once the cavity is filled with concrete, the air pressure is released, and the formwork separates from the concrete wall, making it easy to remove. Pneumatic wall formwork is lightweight and requires fewer laborers to operate. It is suitable for large construction projects since it can be adapted to different wall lengths and heights.

• Engineered Formwork System

  Engineered wall formwork systems are prefabricated units. They consist of metal panels, steel I-beams, and adjustable diagonal braces. The metal panels are connected to steel I-beams to form a strong, rigid structure that can hold heavy concrete. Engineered wall formwork is suitable for large-scale construction projects. It can be customized to fit different wall shapes and sizes, and it is easy to assemble and disassemble. However, it is more expensive than traditional wall formwork.

• Timber Formwork

  Timber formwork is made from high-quality plywood, timber, or softwood. It is designed to hold wet concrete in place until it sets to form a wall. Timber wall formwork is popular because it is lightweight and easy to handle. It can be adapted to different wall shapes and sizes, and it provides a smooth finish to the concrete wall surface. However, it requires skilled labor to assemble and disassemble.

• Single-Use or Reusable Formwork

  Single-use formwork is made from cheap materials. It is used for one construction project only, and then it is recycled. Single-use or disposable formwork is popular because it is cheaper and more affordable. It can be adapted to different wall sizes and shapes.

Function and feature of wall formwork

The functions of formwork for walls include providing a mold into which concrete is poured and supporting the weight of the wet concrete until it hardens.

The features of wall formwork include:

• Materials: Wall formwork is made of plywood, metal (usually aluminum or steel), or engineered composite materials. Plywood wall formwork is a popular choice because it is durable, provides a smooth finish, and is relatively lightweight. The plywood face is often made of high-grade, phenolic-resin bonded plywood to ensure a strong, smooth concrete finish. The framework is typically made of high-strength, lightweight aluminum or steel. Aluminum formwork is known for being lightweight and easy to handle. Steel formwork is more durable and can be used for a wider range of project sizes. Some modern formworks use composite materials that are lightweight and resistant to corrosion.
• Adjustability: Many formworks are adjustable to accommodate different wall heights, lengths, and thicknesses. This is particularly common in modular formwork systems.
• Reusability: A key feature of formwork is its reusability. Quality formwork can be used multiple times for different projects or different walls within the same project. This is especially true for aluminum and steel formwork systems, which are designed for repeated use.
• Ease of Assembly and Disassembly: Wall formwork is designed to be assembled and disassembled quickly and easily. This feature is critical on construction sites to save time and labor costs. Many modern formwork systems use pin-and-hole or wedge-based systems for quick assembly and disassembly.
• Concrete Finish: The quality of the concrete finish is a crucial aspect of wall formwork design. Features like smoothness, strength, and durability of the concrete are affected by the formwork surface material. Some formworks have features to ensure a high-quality concrete finish, such as smooth, non-stick surfaces and release agents.
• Safety Features: Wall formwork systems include safety features to ensure the safety of construction personnel and structural integrity. These safety features include safety locks, bracing systems, pressure gauges, and anti-bursting systems.
• Load Capacity: Wall formwork is designed to support the weight of wet concrete, which can be substantial. Quality formwork can handle high loads without collapsing or deforming. High-strength materials and robust design ensure load capacity.
• Weather Resistance: Some wall formwork can resist various weather conditions. For instance, some formworks can resist rain, wind, and extreme temperatures, while others have waterproof features.

Scenarios of wall formwork

Formwork is an essential component in construction projects involving concrete walls. Its applications extend across various industries and project types, including:

• Construction of Buildings

  Formwork is used to construct concrete walls in residential, commercial, and high-rise buildings. It offers a cost-effective way to build consistent walls and provides insulation and architectural finishes.

• Bridges

  Bridge construction involves using form walls to create abutments, piers, and girders. The formwork is tailored to accommodate different span lengths, widths, and clearance heights.

• Parking Structures

  Concrete walls are essential in constructing parking structures. Formwork is crucial for creating ramp walls, column walls, and shear walls in multi-storey and single-storey parking structures.

• Tunnels

  Wall formwork is also applicable in tunnel construction. It is useful in the construction of tunnel walls, especially in urban areas and metro rail projects where tunnel walls require a rectangular shape and smooth finishes.

• Retaining Walls

  Formwork is also used to construct retaining walls in concrete. It is a cost-effective way of building cantilever walls, gravity walls, and counterfort walls in different sizes and shapes.

• Sound Walls

  Formwork is used to construct sound walls along highways, railways, and busy roads. It ensures consistent wall thickness, structural integrity, and finishes.

• Basements

  Formwork is used to construct foundation walls and basement walls in building structures. It helps create walls of different heights, widths, and thicknesses.

• Infrastructure Projects

  Wall formwork is used in various infrastructure projects, including water treatment plants, military installations, and schools.

• Industrial Facilities

  Concrete walls are essential in manufacturing plants, warehouses, power plants, and refineries. Formwork is used to construct structural walls, tank walls, and thick walls of large-diameter concrete structures.

How to choose wall formwork

Choosing the right formwork for a project involves considering various factors. Here are some key factors to consider when selecting wall formwork:

• Project requirements

  The first thing to consider is the type of project, whether it is a residential, commercial, or infrastructure project. The size and complexity of the project should also be considered as well as the design requirements, including the shape, size, and finish of the concrete walls.

• Cost

  The overall budget should be considered to ensure the formwork chosen is within the budget. Also, consider the initial costs of purchasing or renting the formwork as well as the labor and materials needed for setup and takedown. Life cycle costs include maintenance and repair costs as well as resale or rental potential.

• Wall formwork types

  It is important to look at the different types of formwork available and choose the one that is suitable for the project. Each type has its advantages and disadvantages; it is important to understand them all before making a selection.

  For instance, concrete formwork is the most commonly used, and it involves using concrete as the forming material. It is suitable for a wide range of applications and can be customized to fit different shapes and sizes.

  Timber formwork is another type, and as the name suggests, it uses timber materials. It is lightweight and easy to handle but requires skilled labor to construct.

  Steel formwork is another popular type, and it uses steel materials. It is durable and reusable but more expensive than timber formwork.

• Labor skills

  The skills and experience of the labor force should be considered. If the labor force has experience with a specific type of formwork, it should be chosen to reduce the cost of training. Also, the complexity of the formwork system should be considered. Simple systems require less time and effort, while complex systems require skilled labor.

• Time

  When choosing wall formwork, it is important to consider the construction time. For instance, if the project requires fast construction, then a formwork system that is easy to set up and dismantle should be chosen. Additionally, the availability of formwork can affect the project timeline. It is important to consider the lead time required to procure the formwork.

• Safety

  Always ensure the safety of the construction crew by choosing wall formwork that complies with safety standards. Also, choose formwork that is stable and easy to operate.

wall formwork Q & A

Q1: What is the maximum height of wall formwork?

A1: There is no maximum height for wall formwork. However, as the wall formwork becomes higher, it also becomes more complicated and more expensive. Therefore, it is advisable to use other methods of casting concrete walls, such as jump form, climbing formwork, or crane-lifting formwork, when the walls are over 6 meters high.

Q2: What is the maximum reuse of wall formwork?

A2: The maximum reuse of wall formwork depends on the type of concrete formwork being used. For steel wall formwork, it can be reused up to 300 times, while for plywood wall formwork, it can be reused between 10 to 15 times.

Q3: How should the wall formwork be maintained to ensure durability?

A3: If the formwork is wood, it should be kept dry to prevent rot and should be kept moist to prevent cracking due to overheating. Additionally, the wood formwork should be maintained by applying release oil. For steel formwork, proper cleaning after use goes a long way.