Recent research has shed light on a significant phenomenon in concrete durability: the behavior of alkali-silica reaction (ASR) post-dormancy. Conducted by Ahsanollah Beglarigale from Istanbul Okan University, Civil Engineering (Master), this study offers crucial insights into how concrete structures, previously affected by ASR, can be better managed and repaired.
ASR is a chemical reaction that occurs when alkalis in cement react with silica in aggregates, leading to expansion and cracking. While previous studies have indicated that drying can temporarily halt this reaction, the new findings reveal that after a seven-year dormancy period, the potential for expansion can resurface, posing risks for construction projects relying on the integrity of concrete.
Beglarigale’s research involved testing various mixtures of Portland cement and supplementary cementitious materials (SCMs) under accelerated conditions. The results demonstrated that the expansion behavior of the concrete differed significantly based on the presence and quantity of these SCMs. “In mixtures with insufficient SCM, the residual expansions were primarily driven by the swelling of old gel,” Beglarigale explained. “Conversely, those with adequate SCM showed new gel formation, which mitigated pre-dormancy expansions.”
This distinction is particularly relevant for construction professionals and engineers who are involved in the repair and maintenance of concrete structures. Understanding the mechanisms behind ASR can lead to improved strategies for selecting materials that enhance durability and longevity. The implications of this research extend beyond mere academic interest; they touch on the commercial viability of construction projects, especially in regions where ASR is prevalent.
The study emphasizes the importance of incorporating sufficient SCMs in concrete mixtures, which not only reduces the risk of expansion but also contributes to sustainability efforts by making use of recycled materials. As the construction industry increasingly prioritizes eco-friendly practices, this research aligns with broader trends towards sustainable development.
Published in the ‘Journal of Sustainable Construction Materials and Technologies,’ this study serves as a pivotal resource for professionals aiming to navigate the complexities of concrete durability. The findings underscore a growing need for rigorous testing and thoughtful material selection in the face of evolving challenges in construction. As the industry moves forward, embracing these insights could lead to more resilient infrastructure and ultimately, safer, longer-lasting buildings.