In the quest for more durable and sustainable construction materials, researchers have turned their attention to alkali-activated concretes (AAC), offering a promising alternative to traditional Portland cement. A recent study published in the *Journal of Sustainable Construction Materials and Technologies* (translated to English as *Journal of Sustainable Construction Materials and Technologies*) sheds light on the performance of AAC under harsh chemical conditions, particularly in the presence of sulfuric acid. The research, led by Celal Karaba from the Department of Civil Engineering at Istanbul Gelisim University in Istanbul, Türkiye, provides valuable insights into the durability of AAC, which could have significant implications for the energy sector and other industries exposed to aggressive environments.
The study focused on the resistance of AAC to 5% sulfuric acid, a common challenge in industrial settings such as wastewater treatment plants, chemical processing facilities, and certain energy production environments. Karaba and his team manufactured AAC using a blended binder of 50% slag and 50% F-type fly ash, activated with a mixture of sodium hydroxide and sodium silicate. The researchers varied the binder content and activator-to-binder (A/B) ratios to assess their impact on the material’s durability.
One of the key findings was that higher binder content led to increased gypsum formation and weight gain in the AAC specimens. “We observed that the specimens with 600 kg/m³ binder content exhibited more gypsum and higher weight gain,” Karaba explained. This suggests that increasing the binder content can enhance the material’s resistance to sulfuric acid attack. However, the study also revealed that the A/B ratio had negligible influence on visual appearance and weight variation after acid exposure.
The results indicated that the highest durability was achieved with the maximum binder content of 600 kg/m³ combined with a 0.45 A/B ratio. Conversely, the lowest resistance was observed with the minimum binder content of 400 kg/m³ and a 0.55 A/B ratio. The researchers also noted that reducing the additional water content to 7.5% by binder weight could improve the mechanical strength of AAC, particularly for high-binder mixes.
The implications of this research are significant for the energy sector and other industries that require materials capable of withstanding aggressive chemical environments. “Understanding the behavior of AAC under sulfuric acid attack is crucial for designing more durable and sustainable structures in industrial settings,” Karaba stated. The findings could lead to the development of more resilient construction materials, reducing maintenance costs and extending the lifespan of critical infrastructure.
As the construction industry continues to seek sustainable alternatives to traditional materials, alkali-activated concretes offer a promising solution. The research by Karaba and his team provides valuable insights into the durability of AAC, paving the way for future developments in the field. By optimizing binder content and A/B ratios, engineers and researchers can create more robust and long-lasting materials that meet the demands of challenging environments. The study, published in the *Journal of Sustainable Construction Materials and Technologies*, highlights the potential of AAC and its role in shaping the future of sustainable construction.