Assessment of the endurance of a crane beam in corrosion of reinforcement ropes

The article examines the effect of corrosion in prestressing strands on the fatigue endurance of reinforced concrete crane beams of type BK 12-7 K7T. The main corrosion mechanisms are discussed, including chloride-induced corrosion, carbonation of concrete, and galvanic corrosion, which are most relevant for industrial structures. A methodology is proposed for assessing the residual service life of beams, taking into account the loss of cross-sectional area in the prestressing strands, supplemented by a probabilistic model of corrosion current density, which improves prediction accuracy. Calculations of the number of cycles to failure were performed for different degrees of corrosion (5%, 10%, 20%), showing that at 20% corrosion, the beam's service life decreases by 2.5 times. The study results demonstrate a significant reduction in fatigue durability with increasing corrosion levels, highlighting the need to account for corrosion factors in the design and operation of crane beams. The proposed methodology can be useful for engineers and specialists involved in condition assessment and repair of industrial structures.