Axial compressive behaviour of corroded circular steel tube columns retrofitted by laser-cladding additive manufacturing.

• Locally corroded steel structures were repaired by laser cladding (LC) additive manufacturing technology. • The stiffness, strength, and geometric dimensions of repaired member are almost the same as those of original intact member. • LC repair technique significantly reduces strain concentration due to local corrosion. • Using LC repair technique can prevent local buckling due to local corrosion. • A FE model is developed to accurately describe axial behaviour of repaired member. Surface damage, such as corrosion, fatigue, and impact, poses a serious threat to the service life and safety of steel structures. To address this issue, this study employed the laser cladding (LC) additive manufacturing technology as a novel repair method for damaged steel structures. The aim was to achieve a "restored repair" that restores the stiffness, strength, and geometric dimensions of the repaired member to those of the original intact member. To evaluate the effectiveness of the LC repair method, axial compression tests were conducted on six circular steel tube columns, including one intact specimen, one corroded specimen and four repaired specimens. The study focused on the steel tubes with mid-height surface corrosion and also investigated the influence of corrosion angle, corrosion depth, and repair material on the mechanical behaviour of the repaired members. The experimental results showed that the stiffness and strength of the repaired compression members were restored and even slightly enhanced compared with those of the corroded member. The strain analysis indicated that the LC repair technique could significantly reduce stress/strain concentration caused by local corrosion. Furthermore, finite element models for simulating the axial compressive behaviour of repaired circular steel tube columns were developed and validated by comparing the experimental and numerical results. The findings of the paper confirm that the proposed LC strengthening method provides an additional solution for effectively repairing damaged steel structures. [ABSTRACT FROM AUTHOR]