What is setting-time?

Answer 1

That varies from mix design to mix design and in highly influenced by the weather (temperature and humidity). Concrete can be made to reach initial set in under and hour, or can be delayed for days if needed.

A typical mix on moderate conditions may take a 2 to 3 hours to reach initial set.

Initial set is just the first 500 psi... it will continue to hydrate and "set" as long a moister is present. Concrete can continue to gain strength for months, years and even decades (though less and less and time goes on).