Hypertufa

[sbk]

Hypertufa is a method of mixing cement and peat to get a nice natural limestone looking product. For example:

Now, my question, has anyone tried it? If so, whats been your most successful mixture and can you substitute coir (coconut husk fiber) for peat?

[qualtrough]

Hi SBK,

First time I have heard of that. Here is what Wikipedia has to say. I can't speak with any expertise, but note that they say that the addition of fibers (plastic) increases strength. It may well be that coir fibers accomplish they same thing.

One recipe requires perlite, which I had to look up too:

Perlite is an amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian.

Apparently perlite is heated until it expands 7 + times its weight, which makes it very lightweight. I am not sure if that is available locally or not, anyone?

It would be a simple enough matter to mix up a small batch and test it out. Over to you SBK

Hypertufa

Hypertufa is an artificial stone made from various aggregates bonded together using Portland cement.

Hypertufa is intended as a manufactured substitute for natural tufa, which is a slowly precipitated limestone rock; being very porous, it is favorable for plant growth.

Hypertufa is popular for making garden ornaments, pots and land forms. Hypertufa is relatively light compared with terra cotta or concrete and can withstand harsh winters, at least down to -30 °C (-20 °F).

Hypertufa was invented for use in alpine gardens. Alpine gardeners formerly used antique animal watering troughs, which became rare and expensive.

[edit] Basic Recipe

Using the classic proportions for mortar (1 part cement: 3 parts aggregate) hypertufa is composed of

* 3 parts Portland cement - Type I

* 4 parts peat

* 5 parts perlite

or 3 parts cement: 9 parts aggregate

Other recipes may call for sand or gravel as aggregates, but they add unwanted weight without necessarily adding strength. To increase structural strength and longevity, synthetic reinforcing fibers (plastics, not fiberglass) and liquid acrylic may be incorporated into the mixture. Powdered mineral colors (in small amounts) tint the hypertufa to resemble natural rock.

[sbk]

Right now, its raining non-stop where I live--It'll have to wait until it dries up a bit

But, it is an interesting idea with some really good results --- just wondered how it went in the humid climate--did it dry? Did it mold? etc etc . If I do get around to it, I'll be sure to post my results here