Comment by pjc50
10 hours ago
I wonder what the practical limit is on how thin and light you can make concrete for non-structural items? I can see someone selling concrete mugs on Etsy, for example. Maybe with clever use of fillers and thin walls you could have a version of this you could actually lift. It looks great, especially in contrast to a white IKEA-style office.
Re: decay, I regret not taking more photos of the final days of the RBS "Ziggurat": https://www.edinburghlive.co.uk/news/edinburgh-news/stark-ph... ; at the end it had plants growing from much of the upper levels, making it look extremely Horizon Zero Dawn.
People who make concrete counter tops use a lot of fibreglass fillers to get them fairly thin but if you wanted it truly light weight you’d probably need to make it out of a dense foam and coat it with something that looks like concrete.
My bathroom is a couple mm of microcement over Schluter Kerdi-Board foam, it's fairly strong. I think it can hold a laptop no problem.
Concrete counter top mixes usually use either much smaller, or no aggregate and use more sand. The mixes resemble mortar more than concrete and they are typically a little harder and less forgiving to work with.
Even structural items can be made quite thin! There is a college design competition to make concrete canoes which can be 3/8" to 7/16" thick: https://www.concretecanoe.org/2008Triva/Florida2008DesignPap...
oh wow that takes me back. I remember touring, i think it was Texas A&M, in HS and they showed off their "concrete canoe" to the group. This would have been in the late 1900s.. 1995 or around there.
There have been ships made of concrete.
https://en.wikipedia.org/wiki/Concrete_ship
I've read that adding a little bit of graphene can make concrete much stronger, lighter and easy to shape, so would allow for thinner objects.
There are a lot of additives to concrete - the industry is large and has put a lot of money into research over the decades. You can read many many books on the pros and cons of different options.
Translucent concrete: https://www.allplan.com/blog/translucent-concrete/
You could mix concrete with other materiais too. I worked as a lab assistant in a engineering lab for some time. Putting styrofoam into the mix would result in lighter concrete within acceptable levels of resistance (for low level buildings). You might be onto something
> Maybe with clever use of fillers and thin walls you could have a version of this you could actually lift
You could likely also pour something like this out of aircrete, which would make it a lot lighter even at the same thickness