Types of Formwork Used in Concrete Construction
Concrete is a widely used construction material thanks to its versatility, durability, and strength. To be used as a building element, it must be poured into specialized molds known as formwork. Formwork can be classified according to material, element supported, and whether it’s intended to be temporary or permanent, but this guide will focus on the materials used to make concrete forms.
Steel Formwork is becoming increasingly popular thanks to its long service life. Steel is not the cheapest material used to construct concrete forms, but it provides a greater return on investment thanks to its ability to withstand multiple uses. If contractors expect to complete multiple projects that require supporting the same concrete elements, steel forms are the way to go since they are:
- Strong and durable
- Able to create a smooth finish and reduce honeycombing.
- Easy to install and dismantle
- Suitable for curved structures
Aluminum formwork offers some of the same advantages as steel. It’s more durable and versatile than most materials, easy to use, and can create a smooth finish. However, it’s nowhere near as strong or as dense as steel, which means it’s not always an appropriate alternative.
Many researchers believe that timber was used to create some of the very first concrete forms, which date all the way back to ancient times. Some contractors still use timber forms today since they are flexible in use, comparatively lightweight, and economical for small projects. However, timber has a short lifespan and is time-consuming to install and remove.
Plywood can be used with timber to construct lighter forms that are easier for laborers to work with. Its primarily used as sheathing, decking, and form linings.
Plastic formwork is most appropriate for small projects that feature repetitive concrete-working tasks, such as housing developments. Plastic is robust, lightweight, and great for constructing interlocking panels and modular systems. However, because the components must be prefabricated, it’s less flexible than most alternatives, including timber and plywood.
Specialized fiber-reinforced plastic can also be used to construct permanent forms. In this context, the plastic provides corrosion resistance and is used primarily in columns and piers. Fiber-reinforced plastic permanent forms are now considered a viable alternative to coffers, which are composed of two grids reinforced by stiffeners and linked using articulated connectors.
Even construction workers may be surprised to learn that some types of formwork are made from high-strength but lightweight sheets of fabric. Also known as flexible formwork, fabric formwork is used primarily for projects that have many irregular or complex shapes.
The Importance of High-Quality Formwork
Regardless of which type of formwork a concrete construction foreman chooses for a particular project, product quality is the key to making sure everything goes smoothly. Whether contractors are purchasing cheap plywood forms for a single-use application or highly durable and reusable steel formwork, they should only buy these products from established, reputable manufacturers that specialize in formwork construction. These formwork experts should also be happy to recommend specific products that will fit a customer’s application.