Title: Beneficial Use of Carbonation for Concrete

Author(s): S. Monkman, C. Logan, and Y. Shao

Publication: Symposium Paper

Volume: 235

Issue:

Appears on pages(s): 147-162

Keywords: carbonation curing; cement; CO2 sequestration; concrete; greenhouse gas

DOI: 10.14359/15861

Date: 3/22/2006

Abstract:
A beneficial use of carbonation technology to sequester exhaust CO2 in concrete through accelerated curing was studied. The carbonation took place in a chamber under 500 kPa pressure, at ambient temperature, for two hours and with a 100% concentration CO2 to simulate the recovered CO2 from a flue gas. Both Type 10 and Type 30 Portland cements were used in concrete containing 0%, 25%, 50% and 75% of either quartz aggregates or lightweight aggregates. The performance of carbonated concrete was evaluated by strength development and mass gain. For a 15-mm thick sample, a 9-16% CO2 uptake in two hours was achieved. Analysis by X-ray diffraction indicated calcite formation. Samples collected from the surface or the core, immediately after 2-hour carbonation or 7 days later, contained consistent carbon content. The strength after 2-hours carbonation was close to that of reference samples cured 7 days in a moist environment. Carbonated concrete demonstrated a much finer and denser microstructure and a much higher resistance to atmospheric carbonation shrinkage.