The paper presents two cases of reinforced and prestressed concrete structures damaged by corrosion in chloride-based industrial environments having as main aggressive agents: chlorine, hydrochloric acid and chlorides. To evaluate the corrosion damage of the concrete structures, in-situ and laboratory tests using specific investigation techniques were performed. Investigation of the damage state of structures revealed that many of the examined structural elements showed severe damage due to corrosion. This damage was in various stages of development and had a different influence on the resistance, stability and durability of structures. The corrosion-damage of the structural elements was favoured and accentuated by the absence of efficient intervention measures (repair, corrosion protection) for these elements. In order to ensure normal service conditions of the reinforced and prestressed concrete structures there were proposed intervention measures to remedy existing damages, regarding repair, strengthening, replacing, and corrosion protection of the damaged elements.