Superior CO2 uptake and enhanced compressive strength for carbonation curing of cement-based materials via flue gas. (5th September 2022)

• Record Type: Journal Article
• Authors: Liu, Lixi; Liu, Yilun; Tian, Xiaogeng; Chen, Xi
• Is Part Of: Construction & building materials. Volume 346(2022)
• Publication Date: 2022-09-05
• Subjects: Carbonation curing -- Cement-based materials -- Flue gas CO2 -- Carbonation curing mechanism; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2022.128364
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: The carbonation capacity of 20% CO2 is higher than that of pure CO2 . The carbonation strength is proportional to CO2 uptake, but not to reaction time and pressure. The highest strength is obtained under proper combination of carbonation and hydration. The carbonation mechanism for the flue gas and pure CO2 is analysed. Abstract: Carbonation curing of cement-based materials is an important pathway for CO2 utilization and sequestration. Most previous studies focused on pure CO2 carbonation curing. In this work, we demonstrate superior CO2 uptake and enhanced compressive strength with flue gas (20% CO2 concentration) carbonation curing. The flue gas carbonation rate is smaller at the beginning of curing, but the CO2 uptake and compressive strength are larger than that of pure CO2 curing at 12 h carbonation. Moreover, the growth rate of the post hydration strength is inversely proportional to the CO2 uptake, but under proper combination of carbonation and hydration curing, the 28d strength of the flue gas carbonated specimen can be higher than that of the hydration specimen. The carbonation curing mechanism for the flue gas and pure CO2 is discussed from a microscopic perspective. The higher carbonation capacity of lower concentration CO2 in cement carbonation curing may inspire new pathways in carbonation management.