Diagnosis of expansive reactions in concrete dams: Experience and case studies

Expansive reactions are a common pathology in concrete dams. The most usual alkali-aggregate reaction (AAR) and the less frequent internal sulfate attack (ISA) have been extensively studied. The causes, the chemical reactions and the resulting products are well-known. To provide further insight, this paper presents the lessons learned along the 30-year experience of a group dedicated to the diagnosis and study of concrete dams with expansions, illustrated with two real cases.