Assessing the Contribution of Each Mechanism to the Overall Deterioration in Coupled ASR + ISA-Induced Damage

Physical and chemical interactions between different internal swelling reactions (ISR) play an important role in predicting future deterioration, structural implications, and management strategies of ISR-affected structures. Estimating Alkali-Silica Reaction (ASR) and Internal Sulfate Attack (ISA) contributions to the overall damage in combined attacks may support decisions on prognosis investigations (i.e., experimental and modeling). However, determining the contribution of each mechanism has been challenging. In this context, concrete infrastructure members distressed by ASR+ISA were assessed through a multi-level protocol to identify the cause and extent of induced deterioration. A novel approach was proposed to quantify the damage features generated by ASR and ISA separately. Additionally, SEM-EDS was performed to support the multi-level evaluation. The results show that the novel approach provides interesting results for estimating the influence of each mechanism in the overall deterioration process. Furthermore, it was identified that the leading mechanism may change depending on the overall degree of damage.