Alkali–silica reaction (ASR) is a significant durability issue for concrete structures, particularly those exposed to moist environments. ASR occurs when reactive forms of silica found in some aggregates react with the alkaline hydroxides in concrete, primarily derived from the cement. This reaction forms a gel that can absorb water and swell, exerting internal pressure within the concrete that leads to cracking, expansion, and ultimately, structural damage. Understanding ASR is crucial for maintaining the integrity and longevity of concrete infrastructure, especially under severe environmental conditions that can accelerate the reaction.