When cracks form in the concrete, they preferentially travel to the lime clasts, which have a higher surface area than other particles in the matrix. When water gets into the crack, it reacts with the lime to form a solution rich in calcium that dries and hardens as calcium carbonate, gluing the crack back together and preventing it from spreading further.
Master_Foo 0 points 5 months ago
This is the minimal infrastructure required to make modern concrete:
https://duckduckgo.com/?q=cement+plant&iax=images&ia=images