Whether building a small garden patio or a concrete skyscraper, construction projects of any size require formwork to ensure that the poured concrete takes the right shape. Formwork is a temporary structure that molds the concrete into the desired shape, supports it while it sets and controls its position and alignment. It can be made of wood, plywood, plastic, fiberglass and many other materials, and it can either arrive on a job site in component pieces that workers assemble themselves or be prefabricated off-site and hoisted to the correct location with a crane or another type of lift.
Effective formwork must be rigidly constructed to withstand both the weight of the fresh concrete and the dead load — or permanent loads, such as structural members — that it holds in place, and efficiently propped and braced both horizontally and vertically to retain its shape. It must also prevent cement leakage throughout the entire structure and be able to accommodate any movement that might occur during the construction process.
Formwork for concrete comes in a wide range of shapes and sizes, from a simple slab of concrete to a full-scale wall or bridge pier. The design and construction of each project is unique, so formwork must be adapted to the specific structural requirements. In some cases, the formwork is even built into a structure’s design, with concrete being cast into a special template for particular purposes.
The material used for formwork varies as well, with wood being a popular choice. More recently, however, options like fiberglass and fabric are gaining popularity, as they can provide superior strength, durability and cost-efficiency compared to wood. In addition to these benefits, they can also offer greater flexibility when it comes to the finished shape of the concrete and are quicker and easier to erect and dismantle than wooden formwork.
Once the formwork has been erected, it must be treated with a release agent. This is a compound that prevents the concrete from sticking to the formwork. This is necessary because untreated forms can leave marks or distort the surface of the resulting concrete. Once the concrete has cured, the forms are removed. This is known as stripping in the construction industry and can be repositioned, stockpiled for future use or, in some cases, destroyed.
It’s important that contractors erect and use formwork that’s safe and easy to operate. To reduce the risk of injury, it’s best to work with a supplier that has extensive experience with the type of formwork required for the project. This is especially crucial if the formwork will need to be lifted with a crane or other heavy machinery. Workers should also be thoroughly trained on how to properly handle and use the formwork for concrete. In addition, all workers should be oriented to the safety risks associated with working with the system and have appropriate health and safety plans in place. This will help to ensure that the project is completed safely and on time.
