Dirt + concrete

Has anyone on here ever done this or even heard of it? Apparently if you mix in some cement mix, or even lime into the jumps they hold their shape and harden really well. Thanks yo. :fruit:

You know, I have often thought of what would happen if one did that with some of the areas that required lots of gold on a steep grade.

I think it might have been done on this one section on pipeline "a steep hard left corner" years ago. The gold almost looks like some concrete had been added. Or I could be completely wrong on this one.

Not sure if it's good or bad. Not enough experience with it to say.

Doesn't redbull do that for their jump comps? Or do they just genetically mutate dirt to make it look incredible.

yes it works,it's called soil cement.it's under all the newer taxi ways at yvr ,it's a foot thick under the concrete.I think it would stand up pretty good.mix dry cement powder with sandy dirt"gold"and pack.the "gold" just needs to be moist for the cement to do its thing.

I to have thought about this but decided that I needed to come up with a way to contain the cream while it is setting up. I would imagine that it is a good idea to keep the lime from running into creeks.

We've used a mixture of dirt and "post haste" to firm up the lips of jumps, works really well and lasts along time. Pretty cheap to buy from what I hear from the buddy who's in the construction biz.

Cement powder is often added in a relatively small proportion to sand to make a dry bed to lay paving stones in them. As the mixture absorbs water from the underlying soil or when it rains it sets up solid, however not too solid that it can not be broken up or excavated by hand tools, unlike concrete.

In the construction industry you will often hear of something called controlled density fill (CDF) or low strength concrete. Its a similar thing, instead of having a high strength, it is a self compacting cementitious material that can easily be excavated at a later date if required, i.e has a compressive strength in the order of 200-500 psi as opposed to cement [HTML_REMOVED]2000 psi

These may help:

http://www.co.stark.oh.us/internet/docs/sanitaryEngineers/Item%206C%20-%20Low%20Strength%20Mortar%20Backfill.pdf

http://www.concretethinker.com/applications/Controlled-Density-Fill.aspx

You will probably have to experiment to get the right mix.

Good Luck

Used it on a heavily used berm a few years ago, just rake it through the dirt and hope for rain…like thats a long shot. Its rock solid to this day.

Sounds good, thanks guys. I'll try and get er on the go this weekend and let you know how it works out.

Yes it works- used it with many different soils in a few different climates and it works great. You can buy 40 kg bags for $10.00 at home depot. You might want to consider a small experiment in your backyard before packing in a large heavy fragile paper bag full general purpose cement into the trails. It is also hard on your clothing, so don't wear your new mtb gloves.

don't do it in the forests, we need to keep only natuaral indiginous material in there.
if everyone starts adding cement (its called cement - not concrete - concrete is the product you get when you mix cement, sand gravel and water.) to thier stuff in the woods we will eventually be riding sidewalks. I don't think Cement is toxic in any way to the enviro, but definetly don't take the lime in there.

Yeah man, I hear ya. Our jumps are in a big pit like area full of dirt.

Creeks and fish habitat are highly sensitive to run-off from concrete and/or cement powder, as it can change the pH of the water. Do not use it in an environmentally sensitive area, like a forest.

don't do it in the forests, we need to keep only natuaral indiginous material in there.
if everyone starts adding cement (its called cement - not concrete - concrete is the product you get when you mix cement, sand gravel and water.) to thier stuff in the woods we will eventually be riding sidewalks. I don't think Cement is toxic in any way to the enviro, but definetly don't take the lime in there.

It's very, very basic. Construction projects will get raped by MOE if concrete runoff water/wash water is allowed to enter streams/riparian areas etc. You might be able to get away with a bit, but don't go dumping the rest of your bag in a creek ;)