Apart from the primary loads there are other most of the times incalculable loads that cause less intense, secondary stresses. These are successfully carried in areas with reinforcement while in all other areas they induce the formation of cracks. These type of stresses, except from concrete’s drying shrinkage, are differential deformations caused by sudden differential loadings, e.g. the placement of building materials upon a part of a slab, but mainly they are deformations caused by earthquake forces. The cracking does not affect the structure’s strength but it arises serviceability and aesthetic issues. The cracking’s control can be achieved by an additional light coherence reinforcement placed at the lower and upper slabs’ surfaces in the areas that remain otherwise unreinforced.