The article is devoted to the problem of assessing and predicting the strength of normal sections of bended reinforced concrete elements, which are exposed during operation to long-term force and environmental influences. It is noted that together with the accumulation of concrete and steel reinforcement corrosion damages, the load bearing capacity of reinforced concrete structures can be significantly reduced. At the same time, the existing methods for strength calculating are still applied and do not allow from a single point of view to reflect sufficiently strictly and in detail the stress-strain state of normal sections of bended reinforced concrete elements, taking into account the influence of all operational factors on it. Thereby, based on the nonlinear deformation model of reinforced concrete, a universal calculation procedure was developed. To approve it, the experimental studies of reinforced concrete beams samples that were under static load in sulfate- and chloride-containing aggressive environments for a long time were carried out. New features of corrosion damages accumulation in concrete and steel reinforcement in these aggressive environments were determined. After comparing the experimental and calculated data of normal sections strength, it was concluded that the proposed method has sufficient accuracy and can be used for practical calculations of operated bended reinforced concrete elements with defects and damages.