Condition assessment of ISR-induced deterioration of concrete structures: connecting material analysis and structural-performance evaluation

Internal swelling reactions (ISR), including alkali–aggregate reaction (AAR), and delayed ettringite formation (DEF), are harmful deterioration mechanisms that significantly impact the durability and serviceability of critical concrete infrastructure worldwide. Over the past decades, it has become clear that “single level” assessments, which focus solely on either microscopic (i.e., the damage’s cause) or macroscopic (i.e., the damage’s implications) evaluations, are insufficient to fully understand the impact of current and potential future ISR-induced deterioration of affected structures. Therefore, developing a comprehensive approach that bridges the gap between the damage’s cause and extent at the material scale with structural implications is crucial. Sanchez et al. have developed a multi-level assessment protocol that integrates microscopic and mechanical techniques at the material scale, effectively bridging the gap between micro-mechanisms and macro-performance. This work discusses the use of this protocol, and its possible use in structural evaluation using modeling. The importance of considering key environmental and mechanical factors such as stress history, temperature, moisture, and chemical exposure is analyzed, with the final objective to account for them in the transposition of the laboratory material investigations to the structural scale analysis. A structured management framework is proposed to contribute to more informed decision-making and ultimately enhance the long-term structural health and maintenance strategies of ISR-affected infrastructure.