Cleaning Technique for Repair Painting on a Weathering Steel Bridge

A weathering steel bridge of the Kita-Kobe Route of the Hanshin Expressway exhibited severe salt adhesion and corrosion caused by salt water leaking through a narrow gap between parallel bridge. The damage resulted in the formation of the poor and heavy rust on the constantly wet surfaces by the use of de-icing salt during winter. Although the current practice recommends shot- blast cleaning for repair painting on weathering steel, the technique has not been standardized due to lack of practical experiences. This study shows that an appropriate combination of power tool cleaning and shot-blast cleaning followed by water cleaning can achieve satisfactory cleaning results without affecting the primary painting.