What is the first stage of hydration in cement?

The first stage of hydration in cement is the initial reaction between water and the cement particles, which leads to the formation of a gel-like structure. This process begins almost immediately upon mixing, causing the cement to absorb water and swell. The primary compounds in cement, such as tricalcium silicate (C3S) and dicalcium silicate (C2S), react with water to produce calcium silicate hydrate (C-S-H) and calcium hydroxide (Ca(OH)2), which are essential for strength development. This stage is crucial, as it sets the foundation for subsequent hydration reactions and the overall hardening process.