Build Artificial Rock
How To Build Artificial Rock - The Methods The Professionals Use
By Steve Goodale
Mixing concrete - the most important step in artificial rock making
Mixing concrete is no different than baking a cake. If you do not put the right ingredients into the mix it will not turn out properly. In fact, mixing and curing a batch of concrete is virtually identical to mixing and baking a cake. Except that the concrete bakes at room temperature!
There are many different concrete mixes and various additives and substitutions for ingredients. It is true that lightweight concrete can be created by adding vermiculite, perlite, peat moss or saw dust in place or partially in place of sand. The short answer is - yes you can do this with varying degrees of success and with more than a little trail and error. The concrete mix that is detailed below is specifically designed for two reasons:
1) Maximum strength
2) Maximum sculptability
This mix is engineered to produce a final concrete strength of 50-75 mPa. This is STRONG in fact this is VERY STRONG concrete. This will produce concrete that is far stronger than sidewalks and curbs, even stronger than swimming pool concrete and most concrete found in high rise construction.
It is important to note that you can make concrete batches of all sizes using the simple principal that the ingredients are all proportional to one another. For example the ratio of sand to cement is generally 3:1 or three parts sand to every one part cement. All other measurements in the mix will be based on the 'one part' cement that you are using. For this example the measurements are based on a standard 40kg bag of type ten portland cement being equal to one standard five gallon bucket.
respirator is a MUST as silica, concrete dust and fiberglass are dangerous to breathe!
-One bag type 10 portland cement
-Three buckets fine, clean washed sand
-One and 1/4 buckets un-densified silica fume