Corrosion of rebar within reinforced concrete is a major problem for countries where salt is applied to roads for deicing. Concrete structures are periodically inspected in order to monitor possible damage caused by chloride-induced corrosion of the reinforce- ment. However, the available drilling and visual inspections do not supply sufficient spatial information or can only be assessed in advanced stages of corrosion, respectively. Conse- quently, the condition of bridge decks can only be assessed with low certainty. Therefore, a spatially continuous and non-destructive method detecting chloride in concrete structures is desirable. This Ph.D. thesis deals with the non-destructive monitoring of chloride ion con- centration inside the concrete of bridge decks, in the case of seasonal exposition to chlo- rides. Novel Ground Penetrating Radar data processing methodologies and their prerequi- sites are presented. An experiment recreating chloride contamination processes in concrete was designed. From it, a Ground Penetrating Radar dataset was acquired. The dataset was processed with these novel methodologies. The results analysis enabled the constitution of empiric relationships linking concrete condition and Ground Penetrating Radar datasets.