How it make and what mesure it's mixer?

Concrete is a man-made cast stone that is made of gravel, sand, and Portland Cement that forms the foundation of nearly all permanent construction, and a form of it has been used since the Roman Empire. It is commonly reinforced with steel bars or steel mesh although some mixes may contain fiberglass. Common cement typically has a compressive strength of 2500-3000 pounds per square foot (psf). Other specialized mixes may have compressive strength up to 7500 psf. Concrete differs from mortar and stucco in that mortar and stucco do not contain gravel and have a higher percentage of lime.

Wikipedia defines Portland Cement as "the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in the mid 19th century, and usually originates from limestone. It is a fine powder, produced by heating limestone and clay minerals in a kiln to form clinker, grinding the clinker, and adding 2 to 3 percent of gypsum."

https://en.wikipedia.org/wiki/Portland_cement
https://en.wikipedia.org/wiki/Roman_concrete

Thanks for the answer