How Are Lightweight Concrete Blocks Made?

Concrete blocks are a very common building material for a lot of projects around the home. They are used for everything from privacy fences to outdoor fireplaces and even concrete driveways. However, traditional concrete blocks can be quite heavy to work with and difficult to move and transport around a site. To make the project easier, there are lightweight concrete blocks available that can be used instead of regular concrete. These blocks are made by substituting a portion of the concrete mix with an aggregate that weighs less, such as perlite. However, there are many different methods for how are lightweight concrete blocks made and the specifics can vary depending on what project you are using them for.

For example, Durisol formulated their own wood-fibre concrete and their blocks were very popular in the post-war period because of the loadbearing capacity, fire resistance, and ease with which they could be handled on a building site without the need for expensive machinery. The blocks were hollow and the use of a lower amount of cement and recycled clay bricks and EPS also meant that they consumed fewer natural resources.

For the production of cellular concrete blocks, the air bubbles are formed in a foam and mixed into a slurry that is then poured into molds to produce the finished block. This type of concrete is sometimes referred to as autoclave gas concrete as the mixture is treated in an autoclave to set and harden it, but at the same time the mixture remains porous so that water can still flow through the mixture under normal pressure.