This week will mark the first post on a series traversing alternative and innovative building materials. Today will look at aircrete, a more environmentally friendly utilization of cement.
What is Aircrete?
Aircrete arose out of the need for a more environmentally friendly alternative to traditional concrete. Concrete is produced by using cement mixed with an aggregate. The process of producing concrete releases nearly no carbon emissions. However, the production process for cement is the cause of the concrete industry making up 8% of the overall global carbon emissions. During the production of aircrete, cement is expanded six times its original volume with air, thereby reducing the carbon footprint. Aircrete is also known as aerated concrete. It is a masonry product made by infusing tiny air bubbles , in the form of foam, into a Portland cement slurry. The foam acts to expand the volume of the cement several times which results in an inexpensive building material that is far more insulating.
What is the benefit of Aircrete?
Aircrete is resistant to fire, water, and insects. It provides insulation from both weather and noise. It is far easier to work with than concrete. It is able to be cut, carved, drilled, and shaped by wood-working tools. It works with nails and screws, and is easily repairable. It makes great subfloors, building blocks, walls, domes, arches, and more. It is a high quality, relatively inexpensive material. Also known as aerated concrete, it has a smooth finish, which saves plastering and labor costs. Being an insulating material, an aircrete structure will save the owner money on energy bills throughout the year.
How is it made?
Aircrete is produced by mixing proper proportions of cement and water in a specific container. First the water is added, then the cement, then they are thoroughly mixed. Foam is then injected into the mixture until it rises near to the top of the container. It is then poured into a form to harden overnight, and covered with plastic to prevent the water from evaporating. Aircrete has good compression strength, but poor tensile strength. However, when fiber-reinforced cement is bonded to the surface of aircrete, the resultant material has both compressive and tensile strength.
How is it used?
Aircrete is most often used for exterior and interior walls. However, aircrete can also be used for several other purposes. Due to its insulating capacity, it is used as precast blocks and panels and concrete slabs in an insulated flooring system. It is also utilized for poured roofs, which increases the insulation capacity of ceilings and attics where heat tends to escape from homes. For households located in cold climates, aircrete can even insulate underground pipes.
Sources
<https://psci.princeton.edu/tips/2020/11/3/cement-and-concrete-the-environmental-impact>.
<https://domegaia.com/blogs/aircrete-dome-mastery/aircrete-101-the-ultimate-guide>.
<https://www.buildwithrise.com/stories/aircrete-everything-you-need-to-know>.
<https://www.builderspace.com/aircrete-vs-concrete-which-is-better>.