Protection of bridge steel structures: modern approaches

The pressing problem of ensuring the life of steel bridge structures, which has become especially critical in wartime in Ukraine due to the strategic importance of maintaining transportation infrastructure, is considered. Particular attention is paid to protecting steel bridge components against corrosion. Modern approaches to corrosion protection are analyzed, including hot-dip galvanizing, duplex systems, thermal spraying, polymer, and nanocoatings. Hot-dip galvanizing is highlighted as one of the most effective methods, forming a multilayer diffusion coating composed of intermetallic Fe–Zn phases. The struc­ture of the coating: including γ-, δ-, ζ-, and η-phases, which provide a barrier in aggressive environments, is described. Results of experimental polarization studies in a model neutral medium (3% NaCl) confirm the protective performance of zinc coatings. Corro­sion potentials and corrosion current densities for 15KhSND steel and zinc are presented. It is demonstrated that hot-dip galvanizing enables an optimal long-term protection stra­tegy for bridge structures, combining high efficiency, economic viability, and environ­mental safety. The obtained results are important for the design, repair, and mainte­nance of bridge infrastructure.