# Making concrete

1. Oct 29, 2008

### matfive

1. The problem statement, all variables and given/known data
hello I have to make a concrete base in metres cubed total 1.68 metres cubed.
The ratio to concrete is 1 part cement to 2 parts sand and 3 parts gravel.
how much cement,gravel, and sand in kilograms?

2. Relevant equations

???

3. The attempt at a solution
???
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Oct 29, 2008

### jhicks

You need to find rough numbers for the density of sand, cement and gravel to do this problem.

3. Oct 29, 2008

### matfive

is it 1/6 times 1.68 metres for cement and how to convert it to kilograms.

4. Oct 29, 2008

### jhicks

Not necessarily. One part (molecule) of cement could take up twice the volume as 1 part (molecule) of sand. You need to know the molecular weight (kg / mol) by knowing the chemical composition as well as the density (in kg/m^3).

Last edited: Oct 29, 2008