The growing demand in modern industry requires increasingly greater demands on the structural performance of the employed materials and, therefore, it has been seen that is necessary to implement a series of numerical models that allow to adequately predict the mechanical behavior of the materials that are subjected to severe loading conditions. All these numerical models require, as input parameters, the main elastic and plastic behavior coefficients of the materials, which in the case of concrete and steel, are well known parameters that are already tabulated in most materials mechanics texts. In the case of structural masonry, the main parameters for the numerical models are very limited in the state of the art, and they are mostly obtained from laboratory tests of the masonry units, which in many cases do not faithfully represent the structural performance of the raw material that constitutes the unit, mainly due to the confinement generated by the geometry of the units and the different volumetric strain conditions to which the same masonry unit is subjected under the application of a punctual load. In the present research a numerical model by means of finite elements is developed. The model allows to establish a correlation of the linear and nonlinear properties of a hollow block of concrete with the experimental results obtained from a set of uniaxial compression laboratory tests. The results of this research will be used in the future for the analysis of masonry structures, especially the post-tensioned type.