In this study, several numerical experiments are performed through the use of ReConAn Finite Element Analysis (FEA) software. These experiments involve the numerical assessment of the nonlinear behavior of reinforced concrete (RC) structures under limit state loading. The main objective of this research work, is the development of an object-oriented FEA code (ReConAn FEA), capable of easily incorporating advanced numerical techniques and modeling methods for the analysis of RC structures through the use of state-of-the-art programming techniques. An excessive literate and numerical research is presented on different methodologies and numerical methods used for the analysis of RC structures. This research reveals the advantages and disadvantages that each numerical method has, through which the proposed Hybrid modeling (HYMOD) approach derived. The HYMOD foresees the combination of beam and hexahedral elements so as to discretize the geometry of any RC building. This is performed in order to decrease the computational demands of the resulted numerical model but at the same time maintain the required numerical accuracy during the nonlinear solution procedure.