On 26/06/2017 16:32, Bill Wright wrote:
On 26/06/2017 15:58, Michael Chare wrote:
When mixing mortar or concrete is there any reason not to use more
cement than necessary? If I use a standard mix I will end up with
surplus cement which won't keep. If I use more cement, I might be able
to avoid buying one bag of sand. Not a major saving, but there is also
the problem of getting rid of the surplus cement.


Since the cement binds the sand gains together I should think that a
serious excess of cement would mean there was cement not in contact with
sand or ballast. That would presumably result in a weaker concrete.

Cement that gets damp sets to form a not very strong substance.

Incidentally the worst thing you can do use too much water. The stiffer
the mix the stronger the concrete.

Bill

However once it is past initial set (Green) the more water it gets the
sooner it will attain maximum strength ... it is not as many think by
drying.