ABSTRACT
Cement is still an essential material in making concrete, but in some modern concretes, it is no longer the most important material because these concretes are in fact composite materials. In a composite material, it is impossible to decide which is the most important material, because by its nature, a composite material has properties that are always much better than the simple addition of each component’s individual properties. In the fable of the blind and the lame, it is impossible to decide who, between the blind and the lame, is the most important character.
