Does slag cement change the hardened properties of concrete?
Slag cement improves many of the strength and durability properties of hardened concrete. Slag cement is a hydraulic binder that, like portland cement, reacts with water to form cementitious material (calcium-silicate hydrate or CSH). It also, similar to a pozzolan, consumes by-product calcium hydroxide from the hydration of portland cement to form additional CSH. The resulting cement paste is stronger and denser, thus improving the concrete.
A list of improvements to hardened concrete follows, with a link to individual Slag Cement in Concrete information sheets for further detail: