25kg of cement is roughly 12L of 'concrete. 12L is 20cmx30x20cm (8x12x8 inches for the freedom loving folks)
Even if you used just cement and water I think you would get more than 12L from 25kg.
>Even if you used just cement and water I think you would get more than 12L from 25kg.
The thing will crack very soon. The density of concrete is around 2.4g/cm3