We're casting cement for testing, and we're not sure about how to calculate for the quantities. We're using a 15.24 cm diameter and 30.48 cm tall mould. We're using a water-cement ratio of 1:2, and a cement-sand-gravel ratio of 1:3:3. We're not sure how to calculate how much of everything we need, and we need the specific quantities for our methodology. Can anyone help?
Total volume of the mould is pi r^2 h = 3.14159 (30.48) (15.24)^2 cm^3 = 22240 cm^3 The usual practice is to dry-blend the solids before adding the water, but I'm going to assume you really mean that the water amount is 1/2 the cement amount (not 1/2 the amount of total solids). You really need only enough water to make the mixture workable, but if 1/2 the cement is the correct amount of water, then the needed quantities are water 22240/15 = 1483 cc = 1.483 liters cement 44480/15 = 2965 cc (dry) sand 44480/5 = 8896 cc gravel 44480/5 = 8896 cc total = 22240 cc Probably best to mix up a bit extra of all the dry stuff in case the amt of water needed turns out to be less than you think.
If you just use cement, once dried it will be that fragile you come put your finger through it, use sand ether 3 to 1 or 2 to 1, ideal mix that 3 parts sand to one part cement, if you want maximum strength mix concrete which is three parts chips, two parts sand and one part cement.
