Recent research published in the Journal of CO2 Utilization sheds light on the process of carbonation curing in ordinary Portland cement, a technique that could have significant implications for the construction industry and carbon capture efforts. Led by Gebremicael Liyew from the Department of Architectural Engineering at Chosun University in South Korea, the study investigates how different precuring conditions and carbonation periods affect the performance of cement mixtures.
Carbonation curing involves exposing cement to carbon dioxide (CO2), which can enhance its mechanical properties while simultaneously sequestering CO2 from the atmosphere. The research highlights that the duration of the precuring phase is critical. The study found that shorter precuring times can hinder the carbonation process, leading to lower CO2 uptake and weaker material properties. Specifically, it was noted that “short precuring durations hindered carbonation, resulting in lower CO2 uptake, strength, elastic modulus, and higher shrinkage.”
In contrast, extending the precuring time to one or three days significantly improves the results. The researchers observed that a one-day precuring followed by a day of carbonation at a 10% CO2 concentration resulted in increased calcite precipitation on the surface of the cement, which is beneficial for enhancing strength and reducing shrinkage. The balance between drying-induced degradation and the densification of microstructures due to calcite formation was emphasized as crucial for achieving desired material properties.
This research opens up commercial opportunities for the construction sector, particularly in developing more sustainable building materials. By optimizing precuring conditions, manufacturers can produce cement with improved mechanical properties while also contributing to carbon reduction efforts. As the construction industry increasingly seeks to lower its carbon footprint, adopting carbonation curing techniques could be a viable pathway.
Liyew’s findings suggest that understanding the specific requirements for different binder types and mix proportions can lead to more effective use of CO2 in cement production. This not only enhances the sustainability of construction materials but also aligns with global goals for carbon reduction. The ability to sequester CO2 while producing stronger and more durable concrete could transform industry practices, making it a win-win for both the environment and the economy.
