Abstract
Soluble salts may be transferred to a steel bridge or other structure as an airborne aerosol (generally from marine or industrial sources), wind-blown debris, and debris transferred from vehicles. Perhaps the most significant source of soluble salts on bridges is from de-icing materials. Once on the structure, salts may become incorporated into corrosion scale, poultice, or crevices. There is substantial data demonstrating that soluble salts can affect coating performance, though there are varying opinions regarding the acceptable level of soluble salt contamination.
A variety of surface preparation techniques may be used to remediate soluble salts prior to coating application. Sometimes multiple techniques are used to reduce soluble salt contamination below the prescribed limits. This paper presents data on commercially used soluble salt remediation techniques evaluated in a laboratory setting. The reduction in soluble salts was measured for each technique. The data shows that the effectiveness of the remediation techniques is highly dependent on the surface being remediated. In some cases, pressure washing may be adequate, while a combination of methods may be required in other instances.
