Numerical modeling is often used to assess the load-carrying capacity of existing structures, especially for complex structural systems such as bridges. These numerical models are always sensitive to certain parameters, such as the mechanical properties of the materials. In the case of concrete structures, the tensile strength and fracture energy of concrete have demonstrated great influence in the numerical evaluation of deformations and capacity. However, for existing structures, the fracture energy value is mainly estimated using empirical formulae based on the concrete compressive strength, as there is no methodology to evaluate it experimentally. This issue leads to uncertainty regarding the obtained values and subsequently influences the results of finite element models (FEM) and capacity prediction. With the aim of reducing this uncertainty, an experimental methodology for the evaluation of the fracture energy in existing structures is validated in this paper. First, uniaxial tensile loading tests were carried out on notched standard cylinders and drilled cores specimens cast under laboratory conditions. Then, crack opening versus load curves and fracture energy values were compared to those obtained from three-point bending tests in notched beams and Finite Element Modeling. The results showed that the proposed methodology can be a potential method to estimate the fracture energy of existing structures, and the notch depth have an influence on the fracture energy value obtained.