Concrete slabs are widely-used in construction to provide flat surfaces when building floors, roofs, or other structures. But not all slabs are the same, and there are sixteen main types of slabs that are frequently used to build a concrete deck.
Every type of slab is unique in its own way, and here’s a quick introduction to each of them:
- Flat slabs are two-way reinforced concrete slabs that don’t normally use beams or girders and instead are supported directly by concrete columns.
- Conventional slabs are supported by both beams and columns. They can either be one-way and supported by beams on two opposite sides, or two-way and supported by beams on all four sides.
- Hollow core slabs has a hollow void running through it to decrease the weight of the slab and so it can be used as service ducts.
- Waffle slabs are also known as grid slabs as they are reinforced concrete roofs or floors that have square grids.
- Hardy slabs use concrete hollow blocks to fill portions of the slab, reducing its weight and the amount of concrete used. It is used in situations where the temperatures are high.
- Pitch roof slabs are inclined slabs that are normally lightweight and are used to create natural-looking roofs.
- Dome slabs are built on conventional slabs by shuttering them in a hemispherical shape and filling it in with concrete.
- Arched slabs are used to build bridges or tunnels and distribute the load on them through axial compression.
- Post-tension slabs use high-strength steel tendons to compress slabs and reinforce them. Because of that they can be lighter, thinner, and longer while still providing a high load carrying capacity.
- Pre-tensioned slabs are similar to post-tensioned slabs only the steel tendons are pre-stressed before the concrete hardens. They share the same advantages as post-tensioned slabs, but take longer to cast.
- Prefabricated slabs simply refer to slabs that are cast in advance before being transported to the construction site. Typically they consist of pre-tensioned, post-tensioned, or hollow core slabs.
- Cantilever slabs are designed to be supported at one end. The main reinforcement is in the span that protrudes to the outside.
- Grads slabs are slabs cast directly on the surface of the soil. Generally they are used for basement flooring.
- Sunken slabs are slabs placed at a level below the flooring of washrooms to separate dry and wet areas as well as conceal piping.
- Low roof slabs are used in houses – often above doors or windows. They are closed at all ends except one to create an area for storage purposes.
- Lintels are beam-like slabs placed above openings such as doors or windows to redirect the top load and provide additional support.
As you can see, each of these sixteen types of slabs is different and has a particular role to play. The types of slabs that are required for each construction project may vary depending on the design, style and type of building or structure that is being made.
Some types of slabs such as flat slabs, pre-tensioned slabs, conventional slabs, sunken slabs and a few others are definitely more frequently-used. On the other hand there are certain types of slabs such as dome slabs, arched slabs, pitched roof slabs and so on that are only useful in specific situations.
Now that you know a bit more about each of the different types of slabs, you may be able to figure out which ones you need if ever you’re carrying out a project of your own.