Concrete formwork is the term used to design and make a temporary shape into which concrete is poured and molded for the construction of concrete manholes amongst other applications.
Conventional formwork is made of wood but can also be steel, fiberglass-reinforced plastics, and other materials.
Formwork is an essential part of concrete construction. It must shape green concrete according to the static and architectural requirements. A formwork substructure called a centering (scaffolding) is required for concrete construction in higher elevations. Both can be described as enabling bodies to create permanent members of a structure.
For small and medium-sized jobs, the provision of the concrete formwork is left to the previous experience of the carpenter/contractor on site. Of course, this method relies more on experimentation than on proper structural design. It is essential to construct the same component for safe, economical, and robust formwork, even temporary. The assessment of the correct loads from the raw concrete pouring phase to the final phase of the concrete element that will receive the self-supporting strength is most important. The secondary effects of previous loads must be taken into account and anticipated accordingly in the dimensioning.
Concrete formwork can be designed, constructed, and provided for permanent construction in different materials as follows:
- Timber in its natural state or as plywood. The shapes and forms are created using plywood.
- Structural steel is a versatile material that may be used for a variety of purposes. It is cost-effective, long-lasting, precise, and reusable. Because of their frequent use, mild steel shuttering plates are widely used.
It is critical for your concrete formwork engineers to research your local environment in order to find the best option for the most effective use of formwork materials. The importance of safety, time, and money should guide the selection of materials to be used.
The Importance of Formwork Design
When it comes to concrete and formwork building, it is critical to seek the advice of an expert like the team here at TNN Engineering. Because wet concrete is a fluid, it’s critical to consider the pressure imposed on the formwork, particularly around the base. The pressure will be increased by the height of the pour, which will be amplified in tall parts such as columns and walls. The greatest pour height is usually around 1.5 meters. Larger pour heights can be achieved with correct planning and pouring sequence. A pouring sequence may sometimes be arranged to prevent the formwork from deflecting (shifting) due to pressure.
Formwork can be split into three types in general:
Timber formwork – The most traditional type of formwork is this. The advantage of using timber formwork is that it can be used to create nearly any concrete shape. On the other hand, timber formwork is costly for large projects, especially for a one-off shape that cannot be reused.
Proprietary formwork – Proprietary formwork is pre-fabricated to make assembly and removal a breeze. Proprietary formwork has a limited range of shapes that can be achieved, depending on the provider. On the other hand, this type of formwork is highly effective in high-rise buildings and multistory complexes.
Lost formwork – The term “lost formwork” refers to formwork devoured after the concrete has been poured. In most cases, the formwork serves as a concrete component’s reinforcing member. Steel is frequently used for lost formwork. This steel-concrete component can be thought of as a composite.
Why is Steel Formwork Preferred for Concrete Casting Forms?
Concrete casting forms made from steel are ideal for large scale concrete building projects, as they can be reused and repurposed to form a variety of structures. The most prevalent type of engineered formwork is steel, and there is a lot of it on the market, both new and old. Steel holds its value extraordinarily well since it can be re-used for thousands of cycles.
Steel does not absorb water like traditional formwork, hence honeycombing is less common. Aluminum is less durable, stiff, and powerful than steel. In comparison to aluminum, it is less likely to distort and easier to modify to the needs of a specific project.
If steel formwork needs to be changed, securing components in place to connectors is usually a simple task for us here at TNN Engineering.
It is highly expensive, but it can be used more times than others. They give concrete surfaces a superb polish. Steel formwork is extremely strong and safe for large structures such as dams and bridges.
- Steel forms are more resistant to corrosion and are more durable.
- The construction has a homogeneous and smooth surface finish.
- Excellent reusability.
- The formwork is simple to install and disassemble.
What Are the Requirements for Good Formwork?
Although there are many different types of formwork materials, the following are some of the most common performance characteristics for concrete construction:
- It can bear both dead and live loads.
- Use enough props and supports to keep its shape.
- Leak-proof joints are required.
- The technique must not damage the concrete if the formwork is detachable.
- Material that can be reused.
- The least amount of weight is feasible.
- The material used for the formwork should not warp or distort.
When our expert engineers choose the ideal formwork, they keep in mind the type of concrete and the pouring temperature, as both have an impact on the pressure applied. Formwork must also be able to withstand loads of both wet and dry concrete.
Falsework refers to the structures used to prevent movement during construction procedures, such as poles and stabilisers. A skilled team and proper supervision are required while working with concrete to ensure good quality, that is why you should always reach out to us first!
How To Make Concrete Formwork
Formwork is the temporary structure or “form” used to hold the concrete in its liquid form until it hardens enough to create structural elements such as walls, beams, ceilings, pillars, and manholes, and foundations. At TNN Engineering, we use our experience to create practical and economical formwork concepts that guarantee safety on your construction site.
TNN Engineering offers in-house concrete formwork design and engineering that applies to a variety of construction projects, but has a particular expertise in manhole forms. We prefer to work with forms for manholes but do have experience supplying designs and engineering for all of the most common proprietary forming systems. We can create a design for you from scratch or offer you a professional engineer review and certification of your design. TNN Engineering is not affiliated with an external formwork supplier, so we can also help you decide which formwork system is best for your specific project.
In certain cases, a standard proprietary formwork system will not work and will require custom formwork. Custom formwork can be used when a practical or inexpensive design cannot be achieved through proprietary molds or when the project requires more complex formwork for specific applications.
The focus of our formwork design is to offer our customers inexpensive and easy-to-assemble constructions. To maximise time efficiency and reduce the need for formwork, we can provide a formwork layout and a recommendation for the concreting sequence.
Contact us today to see how we can help you with your next project.