top soil concrete mix for pond

[DeanCurrier]

Well after a 2 year absence I am back to the boards lol. Between a new marrage and building ponds my time has been extremly limited. I remember several years ago on here someone had posted the he mixed topsoil with his concrete for ponds and streams and this gave it a more natural look. I have searched back but cant find it anywhere. Does anyone remember the post or has anyone tried this themselves. I have a large install coming up and the homeowner asked me about doing something like this but I am kinda paranoid till I have some more imput and advice. Also would like to give a big shout out to Doc hope all is well in your world.

[KenAustin]

Hi Dean,

I have never heard of intentionally mixing topsoil into a concrete mix.  My perspective is concrete is a mixture of Portland cement and aggregate.  Soil is a mixture of organic material and aggregate.  The term topsoil implies a high ratio of organic material to aggregate.  The end result of mixing topsoil into a concrete batch is a weak concrete structure.  Consider each piece of organic material either having no strength or when it decomposes in the structure it leaves a void.  The organic material probably makes the finished concrete more water absorbent, which accelerates corrosion of any reinforcing steel and subsequent cracking.  It will also be more prone to cracking due to freeze – thaw cycles.


Cheers,

[DeanCurrier]

Thanx for the reply. That was pretty much my thoughts on the subject but wanted to make sure before I talked back to the homeowner

[Silverdragon]

Dean, adding organic matter to Concrete, as Ken says, is not going to be a good idea structure wise, as it will weaken the final product, and if it starts to rot in there, could end up with disastrous failure at some future point.

If the home owner wants a more natural look, perhaps facing the structure after its built with something else?...
A simple treatment of a mortar and pebble-dash perhaps?...