[amszmidt]

The key here is “based on Portland cement”, which is generally has water repellent added to it making it water proof.

Normal cement, concrete .. Is a different story.

[lazide]

Concrete is generally porous and definitely not micro-waterproof (aka lots of water vapor makes it’s way through). Including if using Portland cement.

It is generally macro-waterproof, however, unless there are large cracks.

[dnemmers]

I'm not sure exactly what you're saying is correct.

'Concrete' is a combination of sand, cement, water and aggregate, that cures together to form.

When the water migrates away from the curing concrete, it leaves open pores behind that future moisture can move through.

https://en.wikipedia.org/wiki/Portland_cement