Just wondering what happens if we mix both types of cement on the same mix? do they interact negatively between them? or will it become like a mid strength HE?
I have not seen anything on the effects of such a practice, but here is my prediction. The cements have different heats of hydration and will cure at different rates. As such, any drying shrinkage that you would have from a single mix would be increased due to additional differential shrinkage. Aside from the cement, the components of the mix will also vary in quantity and/or type, so there are other interactions going on. My advice: don't do it (or if you do it, let us know what happens)
Ooooo, I really don't like that. Agree with motor that differential shrinkage would likely occur. That said, I don't think it couldn't work just that I would look at better ways to do this. For example, type 10 (type I in the US) with additives to get the properties you need.
Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries