Microscopic to Macroscopic Aspects for Structural Assessment of ISR-Affected Structures—Research Outcomes of JCI-TC211A

Despite the importance of the assessment and prediction of structures affected by internal swelling reactions (ISR), robust methodologies have not yet been established. ISR damage of structures occurs through microscopic damaging of the materials due to various chemical reactions and the formation of damaged microstructures, leading to macroscopic stress/strain variations in the structure. Therefore, understanding the relationship between the microscopic and macroscopic aspects is key to refining the performance assessment of structures affected by ISR. To address these issues, a technical committee, TC211A “Technical Committee on Assessment and Prediction of Expansion due to Internal Swelling Reactions in Concrete Structures”, was established and active in 2021–2023 in the Japan Concrete Institute. This committee mainly discussed the ideal direction of test methods and models for assessing the performance ISR-affected structures, with the aim of presenting a more effective and feasible ISR risk-assessment method. In this paper, the outcomes of TC211A are presented.