Isn 't the use of steel fibers in concrete highly inefficient, since they point in all directions and are distributed through the whole mass?
If steel fibers were used as a substitute for strategically placed rebars their use would be highly inefficient. Usually they are used for special purposes for which it is desirable to have them distributed throughout the mass. They are oriented more or less at random, though not completely so. According to a RILEM report by J. Edgington and D. J. Hannant, "Steel Fibre Reinforced Concrete: The Effect on Fibre Orientation of Compaction by Vibration," (Vol. 5~ No. 25, JanuaryFebruary 1972, pages 41-44) it has been found that the sides of the form tend to orient the fibers parallel to it. The vibrator may also cause rotation and alignment of the fibers preferentially in a specific direction.