Concrete DIY questions

[Shtonk]

Been thinking about contributing a skateable concrete sculpture to an inofficial and open local DIY. It's on asphalt and cutting into that is a no-no so I'm wondering do any crete-heads on here have advice for me what a safe angle is where the beginning floor bit of the concrete (sorry don't know correct term) won't immediately chip and fall apart? Thanks!

[behavioralguide]

 Idk what kinda obstacle you mean/want but it will chip anyway... if it were a banked ledge to grind/slide i'd go for a steepness where you hit your nose if you go up. Meaning you got to lift your front truck (weight) anyway so some chipping wouldn't do you any harm.

If you're talking about a jump ramp ish obstacle just put some metal plate at the bottom to ride up because, like I said, it will chip for sure if you just smear it onto the asphalt

[Shtonk]

Thanks dude. I'm thinking China Bank type of deal but going as flat as possible on the angle to make it rideable for a maximum amount of people.

[frontsideNECKTIE]

As noted, chipping is a given if the crete isn't flush with ground. It is mitigatable tho.

Generally, the steeper the better, mostly cause you want the concrete to be as thick as you can, for as close to the asphalt as you can. Long, mellow feathered seams are going to chip faster than a steep, thick corner/seam that is sharp and basically squared off.

For the angle, the above idea of having your nose touch is smart. If you do end up feathering, don't use concrete. The rocks will fuck ya. Either sift the dry cement out or buy portland and basically make a patch where the asphalt meets the mud.

Make sure you cure the fuck out of it. Once the crete is hard enough to not wash away, keep it wet over the next couple days. I'd give it at least a week before skating

There might be better advice, but just my thoughts after doing this same thing at my asphalt lot DIY.

[Shtonk]

Cheers guys!

[biaherl]

Or you can have a single slope barrier delivered for $400. They'll plop it down right where you want it and you can figure the angle you want it at and fill that gap with concrete


Just saying

[Eh]

Please post links to prefabricated concrete features.

[biaherl]

Please post links to prefabricated concrete features.

I'm not sure if you are asking for this

https://www.trafficsafetywarehouse.com/Concrete-Barriers/products/85/

https://summitprecastconcrete.com/concrete-traffic-barriers/

https://www.yelp.com/biz/arts-trench-plate-and-k-rail-service-company-san-diego



or this





lmk

[Shtonk]

Cheers! I'm in Europe and having barriers or premixed crete delivered is much more expensive here unfortunately.

I have another question, maybe don't need to do another thread for it. If I built something that was meant to be a DIY skateable sculpture  that I'm not expecting to live for longer than a month before the council has it cleared out and I filled the bulk of the structure volume out with wood pallets. How thick would I have to make the crete, reinforced with chicken fence, to not break with the wood flexing underneath for a month? Looking to make it as thin and cheap as possible to hold up for a bunch of sessions but not to last through a winter or years of skating with the wood underneath eventually rotting out.

[Plan9Customs]

Just make a fill free quarter and move it to where you want it.

https://m.youtube.com/watch?v=UtzmGN7FX_s&pp=ygUfRmlsbCBmcmVlIGNvbmNyZXRlIHF1YXJ0ZXIgcGlwZQ%3D%3D

Or if you only expect it to last a month make it out of wood.

[Shtonk]

the thing is I'm looking to build something a little weirder and more organic in shape than a simple quarter. building a skateable ramp out of wood is much more expensive than a dodgy concrete-job, no? the multiplex paneling alone should exceed the costs of a crete-job, let alone building an entire under-construction that can actually hold the impact?

But connected to the "more organic shape" - I'm struggling to find advice on timings on when to remove cladding when you still want to manually add and shape stuff on vertical and even over-vertical areas. This isn't the main part of the obstacle but one part would kind of require me to work the concrete a little as if it was clay: adding some bits to a vertical part after that part has its cladding removed and shaping it by hand.  Is that even doable?  Thanks guys!

[Plan9Customs]

You’re still going to need plywood for forms and you can build bumps, pockets, quarters, etc. fill free. Do yourself a favor and jump down the rabbit hole and checkout @skatediy on IG. There’s a shit ton of info there.

[Shtonk]

Thanks, will jump

[Willie]

If you can’t cut the asphalt, leave the concrete edge kind of squared off - not fully feathered out to flat, then finish the seam with bondo or a polymerized concrete mix.

[Shtonk]

If you can’t cut the asphalt, leave the concrete edge kind of squared off - not fully feathered out to flat, then finish the seam with bondo or a polymerized concrete mix.

Cheers! I'm  having trouble finding German equivalents to bondo. Polymerized isn't the same as fibre-reinforced mortar is it?

[Weededed]

[Ray C. Usery]

Expand Quote

If you can’t cut the asphalt, leave the concrete edge kind of squared off - not fully feathered out to flat, then finish the seam with bondo or a polymerized concrete mix.

[close]

Cheers! I'm  having trouble finding German equivalents to bondo. Polymerized isn't the same as fibre-reinforced mortar is it?

They are similar and they both work for fairing in transitions. Personally I prefer mortar because you have more working time

also