A Cement Question

[crokett]

that occurred to me this afternoon. I know cement hardens as the result of a chemical reaction with water which is why it hardens underwater. Anyhoo, why does too much water make for a weaker mix?

[drumpriest]

Being the son of a civil engineer, I would have been yelled at for asking this question in this way. Technically cement is a component of concrete, which is the substance to which you are referring. This has become a common place error, where people use the terms interchangeably. Here is a decent article on the chemistry involved.

http://chemistry.suite101.com/articl...ry_of_concrete

[crokett]

Being the son of a civil engineer, I would have been yelled at for asking this question in this way. Technically cement is a component of concrete, which is the substance to which you are referring. This has become a common place error, where people use the terms interchangeably. Here is a decent article on the chemistry involved.

I know that. I was actually thinking as I typed the post that I need to make sure and say 'concrete' instead of 'cement'. That being said, I am tired. It's been a busy weekend.

Thanks for the article. I think the answer is that less water means less space between the pores of cement and hence a stronger mix.

[Stytooner]

This is precisely why they strength test most major commercial pours. They fill up little shots or cylindrical containers for testing later on. This is how they certify that a slab is poured to design specs.

Just like making a cake, if you don't follow the recipe correctly, your results will vary.

Cement itself will harden with a water mix, so you weren't all that far off base. Just not quite the mix you were looking for.

We usually dressed up our concrete curbs with a portland cement slurry applied over the top of the concrete. This gave everything a smooth even color.

[bruce hylton]

I was told that calling concrete cement was the same as calling bread flour when I was 18 and I have never forgotten that little quip.