A simple recipe for a multitude of products
Concrete is made simply by mixing a few constituents (aggregate, water, cement, addituves, etc...)
But a very large number of recipes can be used to prepare a large variety of concretes whose properties and performance differ greatly.
The recipe can be optimized (a process known as mix design) once the desired performance of the hardened concrete is known (generally the aim is to achieve a certain mechanical strength after 28 days), but its characteristics when fresh are also important (between a few minutes and a few hours after mixing, generally the aim is to achieve a certain consistency and workability).
But it is also necessary to know:
the type of structure which is to be built (a bridge, a road, a tunnel, etc...)
the type of concrete (reinforced concrete, unreinforced concrete, prestressed concrete, ...)
and, above all the climatic conditions, stresses (traffic, impacts) and attack (frost, etc.) the structure will have to withstand.