Alternative approaches to estimating the stiffness of corrosion-damaged beams taking into account localization of corrosion focus and corrosion damage development of concrete based on the model of V.M. Bondarenko are considered. The following methods of determining displacements of corroded reinforced concrete beams of rectangular cross-section are considered. In the first one, the stiffness of the beam in determining the deflection is considered to be constant. In this case, the corrosion-damaged deflections values may be underestimated due to failure to take into account the actual work of reinforced concrete. In the second, the deflection is calculated considering the height of the concrete compression zone that varies along the length of the beam. For these approaches, stiffness reduction in the beam sections in the presence of corrosion damage to the concrete of the compressed zone is modeled. It is shown that in the presence of corrosion damage, the deflections of the structure can significantly increase, which requires mandatory consideration in the life cycle of load-bearing structures of structures when assessing their mechanical safety.

Keywords: reinforced concrete beams, strength of reinforced concrete elements, bending stiffness, deformability, corrosion damage of concrete, height of compressed zone, deflections.