Evaluation of Test Setups for Appraising the Residual Expansion of Concrete Affected by Combined ASR and ISA

Understanding the potential for further deterioration due to internal swelling reaction (ISR) is paramount for managing ISR-affected concrete structures. Despite several studies conducted on this topic, it is still an open question when combined ISR mechanisms occur. Therefore, cores extracted from ASR+ISA-distressed concrete sleeper were subjected to conditions known to enhance the progress of ASR (1M NaOH at 38 ℃), ISA (lime water at 38 ℃), and ASR+ISA (100% RH at 38 ℃). The results reveal that the initial damage degree and leading deterioration mechanism significantly influence further damage kinetics, integrity reduction, and mechanical properties losses. A comparative evaluation of damage progression under individual and combined conditions highlights the importance of specific environmental factors for each mechanism. In conclusion, an accurate prognosis of ISR-affected concrete structures depends heavily on a comprehensive diagnosis, as the cause, the extent of deterioration, and the leading mechanism play pivotal roles in the outcomes of prognostic tests.