I am constructing a concrete circular wall. OD 11ft, ID 10ft, 42in height, 6in thick. 24-30in are in the ground. The questions I have:
I am using the ground and 1/4in plywood for the form. What should I use for a release applied to the plywood to allow for the form to easily pull away from the concrete? Will it discolor the concrete?
I plan to use the wall for a fountian base. Does this size wall need some from of scores in it to allow for expainsion and contraction? I plan to re-enforse with rebar and wire webbing.
What can I use the water proof the concrete?
Replies
Scot,
There are commercially available release agents, along with some other things that also work. The material that meets the most stringent USRA (United States Redneck Association) standards is diesel fuel and used motor oil. This probably violates a bunch of other standards, I don't know.
Rather than try to waterproof the outside of the concrete, you can also use a fairly rich low slump mix with Anti-Hydro, consolidate it well, and cure it wet. There are also chemicals you can apply to the surface, I don't know how long they'd last with constant exposure to water and UV.
If you place the steel properly and use good concrete you should have no problems. You don't want to include any control joints if this is supposed to be waterproof. All control joints do is decide ahead of time where the concrete is going to crack.
It sounds like you're new to this. You might want to get some help on site from someone knowledgable. If a wall this size goes bad it's not going to be easy to correct. At the dimensions you've described, it could weigh about 4 tons, just something to think about.
Ferro-cement is commonly used for the purposes you describe, and may be easier, cost less, and a whole lot more fun. Run a web search on it, if you don't find anything and are interested I'll describe it.
DRC