in case of setting and hardening of cement, the first thing is stiffening
its the initial stage of the cement setting up after it has been hydrated.
Concrete is composed of cement and gravel/stone. When you add water to cement you get a chemical reaction called hydration. That reaction causes the cement to harden over time. The most common reaction that is similar is epoxy glue. Now, don't get me wrong, epoxy glue is NOT hardening because of hydration like cement. The bond in epoxy is an entirely chemical bond. But they are similar because as the epoxy hardens it goes thru a similar process. At first, it's liquid, then the liquid begins to stiffen and then hardens. Remember when you read the label on Epoxy that it has a hardening time (typically it's either 5 minute epoxy or 1 hour epoxy). But as you read on you find that it develops it's maximum strength over a period of 24 hours. As the epoxy dries it first stiffens.
