# How much concrete to order?

If I make 4 of these statues, 1.25x life-size, then how much concrete should I purchase?

The plan is to make a mould and pour into that.

The original Ludovisi Ares is 1.56 m in height. Therefore: (x1.25) 1.95 m high.

Update: I need to know how much Portland Cement (White), how much sand, and how much aggregate to order, and need a suggested recipe for the proportions of each and size(s) of aggregate I should use.

It has to be liquid enough to pour into a mould and take the shape, but strong enough after drying to stand in public and withstand subtropical temperates and humidity, heavy rain, strong winds, and cold temperates (rarely freezing, 0℃ only one day a year if even that).

Finally, I will cure it for a full 28 or 30 days, and want it to have as smooth a finish ad possible.

Any and all advice would be appreciated. Thanks.

• Are you planning on casting (and from what), or removing material from a solid blank? If the latter, what shape? A cuboid or something closer to the finished form? Is the end result to be solid or hollow? Oct 23 '18 at 14:59
• And how big is It? Oct 24 '18 at 1:21
• You can't replicate that with concrete. The detail is too fine for aggregate. You need a cement product designed for casting, probably fiber reinforced. It may also need some internal support. It will require vent holes to allow air pockets to escape, and then cleanup. May 18 '20 at 11:33

## 2 Answers

If each statue is 1.25x as large as the original, its volume will be 1.25 cubed, or a little over 1.95 times the volume of the original. If you can find out the weight of the original and the specific gravity of the stone of which it is carved, you can calculate the volume of stone in the statue and use that to calculate how much concrete you would need for a statue having almost twice the volume. I'll defer to the concrete experts about particulars on that subject.

This is not trivial , and from your questions it sounds like you have little experience. For openers you will need a remarkable elastomeric mold in several sections . and some way to hold it together against the high pressure of the concrete ; roughly 1400 pounds /square foot of mold surface at the bottom.You will need a vibrator. Probably silica sand with no aggregate or crushed limestone aggregate to get a fairly smooth nearly white product. A one inch slump will give the highest strength but may be difficult to fill the mold, so 2 or 3" slump. Likely some steel framework ( armature) would be advisable.