Repair and Treatment of Alkali–Silica Reaction (ASR)-Affected Transportation Infrastructures: Review and Interview

Alkali–silica reaction (ASR) can create significant cracking, compromising the durability and structural integrity of concrete elements. Currently, there is no known way to halt or reverse ASR damage, and the expansion will continue until it impairs ride quality or structural capacity, requiring the replacement of the affected elements. For certain existing structures or structural elements, the progression of an alkali–silica reaction may slow down depending on the type, dimensions of the affected element, service conditions, and environmental factors. Early intervention with repairs, however, may delay the need for replacement and extend the service life of the structure. Repair methods, such as crack filling, sealing, and breathable coatings, help reduce moisture intake and slow expansion. These repairs can also be combined with strengthening techniques to counteract the expansive forces caused by ASRs. The primary goal of these repairs is to extend the life of the structure until replacement or abandonment is necessary. There is a lack of information regarding the long-term performance of repairs and the most widely accepted repair methods. However, the literature and knowledge from the field shows that the time gained through these repairs varies significantly depending on location and exposure conditions, indicating that replacement remains the only reliable solution. Still, given that repairs can cost only 10–20% of full replacement, they remain a viable option for agencies managing limited budgets for immediate replacement.