Several months ago I came across a product called aircrete or foamcrete. It has been around for a few decades but as of today has mostly been used as an insulation material, while its potential for construction has yet to be fully appreciated.
Aircrete is basically mortar filled with air; sand, cement and a foaming agent ~ a type of soap. Special mixing equipment is required to make it but the process is not high-tech, just different from mixing concrete or mortar the conventional way.
The result is a light material that looks similar to Nestlé Aero chocolate bars albeit in concrete. It is so light it floats on water, yet is non-permeable due to the high cement content. It is fireproof and has good acoustic- and thermo-insulation properties. It is also very easy to pour: due to the high viscosity it does not require vibration to properly fill a mold. And most importantly, aircrete is very, very cheap!
The drawbacks are that the airy material lacks the compressive strength of normal concrete, and like normal concrete it has little to no tensile strength. but in spite of being filled with air, it does retain a surprising amount of strength, enough to be used for walls and roofs in single story housing, or non-structural walls in multi-story projects.
Why then, don’t we see aircrete being used all over the world? The reason for this is that the construction sector is conservative, both for legal and for practical reasons. Buildings have to be guaranteed for design flaws, if there are any, claims can harm a company even decades later. It is better to play it safe using conventional technology. Practical considerations have to do with investments in existing machinery and training of personnel.
That is not to say that aircrete isn’t used in the developed world, but its adaptation is still very limited considering the benefits. Looking around in Malta where I am presently, I see only concrete and limestone block for interior wall construction, such a waste!
It is no surprise then that experiments with this low-cost material are mostly taking place in developing countries. Below I have three videos. The first one is a production video from India, demonstrating the characteristics of the material with Bollywood flair:
The second video is from Lithuania, featuring the construction of what appears to be a spec house for low-cost social housing projects. It is a little lengthily with loud rock music, but what it demonstrates is how quick and easy it is to pour a house with this material. Obviously it’s a demo, the reality will not go as quick and flawless, but it would still provide cheap, quality housing for both hot and cold climates:
The last video is my favourite. I was already imagining using aircrete to build another passion of mine: domes, arches and shell structures, when, as it usually goes when you have a good idea, you find someone online who’s already done it. Humanity can be awesome:
This video particularly demonstrate that aircrete can be used as an easy, low-tech material that offers more creative flexibility than any other!
Over the last month I have developed modular construction methods using aircrete that can revolutionize the housing industry especially in a country like Panama. Also I explored different mixtures for different applications, to increase strength or reduce the need for finishing. And while aircrete lacks structural strength to create multi-story buildings, it does offer possibilities to change the way conventional apartment buildings are built. I can’t wait to find a client bold enough to work with me on new construction methods!