cracking of bricks



  • Hi- I am new to the forms and very interested in potentially building a dome within the next year. In reading about aircrete, one of the articles I found advised that due to the brittle nature of aircrete it is not advisable to use as a building material

    http://skill-builder.uk/aircrete-blocks

    I have also read in some of the forum posts that perhaps PVA fibers could be added to the aircrete mix for additional tensile strength. Do you have a recommendation for when added PVA fibers is appropriate? Thanks in advance.

    -j


  • Little Dragon Tamer Major Contributor

    funny thing but I wonder if sawdust is viable....


  • Little Dragon Tamer Forum Facilitator

    Welcome to the forum for aircrete pioneers. Thanks for your interest and your post. Thanks for questioning the norm.

    One of the articles I found advised that due to the brittle nature of aircrete it is not advisable to use as a building material

    For the average do-what-everybody-else-does builder, this information is perfectly correct. For them it is the correct answer for several reasons on several levels. For others, the statement is humorous.

    Brittle is a relative term. The concept of brittle is relative to other materials, and/or what you are intending to build. Giving advice based on a completely relative aspect without stating what it's relative to, leaves a lot to assume.

    Concrete is quite brittle in comparison to certain other building materials such as granite and solid steel. Due to the brittle nature of concrete it is not advisable to use it as a building material without incorporating vast amounts of steel to keep it from cracking apart. I've worked with plenty of concrete and enough aircrete to say that concrete is more brittle than aircrete. Pour two walkways 4-6 inches deep, one pure aircrete and the other pure concrete (no rebar, thanks) and I'm pretty sure the concrete will crack up more.

    Comparing building materials can be fun, but mostly pointless banter unless we know what we are trying to build. For those intending to build a square house with straight walls, I don't advise using aircrete because flat walls set at 90 degrees to each other tend to make incredibly weak structures compared to say, domes. For those interested in making inherently strong geometric structures such as domes, aircrete looms as a seriously viable, affordable, insulative, easy to use, building material.

    I suggest reading this post about fibers. There are others on this forum - try the search function and see what comes up.



  • @zander awesome! thanks for clarifying. I will be happy to continue my investigation. I agree that it looks like aircreet has the advantages you suggest. cheers. -j


  • Major Contributor

    Perhaps part of the problem is language -
    Since the article is in the UK the article is probably discussing Autoclaved aerated concrete (AAC), rather than Domegaia's form of AirCrete.

    The article mainly discusses the problems with using the wrong mix for mud and poor application techniques. Both problems are usually taken care of in a Domegaia type build.