dear /diy/
I'd like to cast a cone from raw concrete.
I'd like to use a similar technique to what was used in brutalist architecture.
I get the concept applied to non organic shapes , but how can this be aplied to a cone.
corbusier did stuff like this.
In my mind it looks like a stupidly intracte process , that can't be it , right ?
>>1008460
Really just a matter of making the form in that shape, and prop it up while the concrete sets
>>1008469
I just don't get how much work I should put in the form.
I mean , they used wooden planks for the pice in the picture as far is i know.
but how were the planks shaped ?
were they shaped at all , can I leave gaps between the boards because of the vicosity of the concret ?
I tried to make two examples of what I mean by shaped boards in the pic
>>1008507
also,
how should I secure the form ?
will wire be sufficent ?
I'm really at a loss here.
I mostly wanna do this because I can't really wrap my head around this.
I have done this kind of thing, for instance i just rolled some corrugated zinc sheets into a cilinder, tied them with wire, and presto! very cute "greekish" colums.
The concrete is viscous enough to not leak (not too much at least) trough small cracks and crevices, if your mold could hold sand or loose dirt, it can hold fresh concrete.
About how precise your shapes need to be, that's completely your call. With a very smooth cast you can achieve a very smooth finish you can even oil or grease your mold to make it come out easily. You might want to go for the oposite, like in brutalist architecture some leave a rough finish where you can see the imperfections of the molds and sometimes even the texture of what was used.
One key thing to have in mind is to vibrate or give small hits to your cast so the concrete really fills all the spaces and shape.
Of course you can choose to leave the piece just as it came out of the mold or polish it. Polished concrete looks incredible.
Ask any other questions, im very experienced in this topic, and probably can help
about how much to secure the form, just keep in mind concrete is super heavy, and when fresh, it tries to push in every direction (picture a water balloon). Wood and wire is enough for small to medium volumes, the bigger you go, the more you need to secure it
>>1008515
great , thank you !
that is the kind of insight I needed.
I'm really tempted to try using boards and go for the beton brut look. I'll try to do a sort of mini version of it, so i'll be using rather small boards.
I guess I'll just try it out.
have you ever built a a irregular shape from planks ?
I guess it's easier if the shape is huge.
is there a usual way of buling the form for something like this ?
like securing the boards with metal straps and screws ?
also , concrete keeps crossing my mind from time to time, do you think there is good literature on the subject outside of traditional building stuff ?
>>1008460
Play with small models and scrap wood. It's an interesting idea.
Visit boatbuilding forums to learn how wood can be used for such interesting shapes. Boats use many curves.
Post results and have fun.
You could buy a shitload of wooden narrow and wide popsicle sticks to make a desktop size model.
>>1008534
the boatbuilding advice is great , I'll look into it
>>1008460
>Fast forward 20 years
>Concrete is crumbling
>Neighbor comes over
>Giant stone bullshit finally gives way
>Huge bolder hands on neighbor fucking him up but not enough to kill him
>You're happy he is safe.. at first.
>You are now being sued for an array of things
what do you do now?
>>1008572
clearly, you kick back with a beer and enjoy the flood of new emotions that raw concrete and expressive primitivism embodie acording to corbusier
>>1008572
>what do you do now?
Because you built it small enough to haul off and used it as yard decor it doesn't squash neighbor. BTW if you were going large you'd require proper engineering including a massive footing, and the concrete would require reinforcement.
It is the shape that's the quest, not the size in OPs pic unless he/she/it is wealthy and wants to spend years of study and practice before attempting the final object. Rome wasn't built in a day.
>>1008572
Say the neighbour was trespassing and vandalising the object d'art.
Then apologise for not killing him with a double tapped headshot the way you're supposed to.
>>1008626
You have yo give notice to vacate for trespassers.
Castle doctrine doesn't extend to your entire property in most jurisdictions, only the primary residence. Even if someone is breaking into your car and stealing your diamonds, you don't have the right to use deadly force to defend your property.
Carpenter specializing in formwork here.
If you want to build something exactly like your picture then you would need a literal ton of rebar and would most definitely not be able to build it yourself. No sheet metal and wire will not work. Even if you build this at half scale it would still require quite a bit of work and definitely some sort of relationship with an engineer. How serious are you about this?
>>1008584
kekd hard
>>1008686
actually I just want to fool around with this right now.
although If everything works out fine , I might try my hand at bigger stuff.
a two meter high raw concrete cone would be pretty interresting.
I'm weirdly into cone shapes right now.
>>1008626
In america you cant do that. Even burglars have to be able to be safe in your home.
If someone robs you, and gets hurt in the process you can get sued for it.
>>1008621
Just because you are suppose to use special engineering methods, and make it safe.. doesn't mean that some guy on the internet is GOING to do it that way.
I think you are grossly underestimating the number of people that wouldnt think twice about making some huge bullshit think out of concrete and nothing else.
Also keep in mind that concrete setting is an exotermic reaction, meaning in large enough volume and/or insulated too much it will heat up uncontrollably and fuck itself up due to thermal stress and water steam trying to escape.
>>1008563
Re: Boat Building.
Look up Ferrocement for boats and also buildings.
It is a steel wire and mesh core construction that is then plastered with cement rather than a mould that is filled. Any shape you can bend wire to is the shape you can make so your cone is easy. I grew up with a ferrocement boat being built in the back yard and that has been floating in the sea for almost 30 years now so it's durable and strong. It is also used for buildings and other constructions. So if you get your materials right and correct sand and cement there is no reason the construction wont outlive you.
The materials can be handled and shaped by hand, mostly one man and are relatively cheap.
>>1008798
depends on the state
>>1008460
You can get 1.5mm ply boards that bend easily. I'd make the frame of the cone and fix the boards on then you should have a decent form.
