Carbonation of Portland Cement Studied by Diffuse Reflection Fourier Transform Infrared Spectroscopy
Artikel i vetenskaplig tidskrift, 2013

Carbonation is a natural ageing process for cement. This study focuses on how the carbonation rate varies with selected hydration times and atmospheric conditions during the early stages of reacting dried cement paste. Diffuse reflection Fourier transform infrared spectroscopy is shown to be a suitable technique to monitor the formation of carbonates in cement. Combined with a previously developed freeze drying technique, carbonation can be studied at specific hydration stages. In ambient air both calcium hydroxide and calcium silicate hydrate (C–S–H) in cement are carbonated. Increased hydration time enhances the carbon dioxide uptake, which indicates that the calcium in the hydration products reacts more easily than the calcium in the clinker phase. In a humid CO2 atmosphere, the carbonation process is so pronounced that it decomposes C–S–H into calcium carbonate and silica. In a moist N2 atmosphere no carbonation occurs, but the sulfate chemistry of the cement seems to be affected due to the formation of ettringite.

carbonation

infrared spectroscopy

C–S–H

cement hydration

Portland cement

Författare

Rikard Ylmén

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Ulf Jäglid

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

International Journal of Concrete Structures and Materials

1976-0485 (ISSN) 2234-1315 (eISSN)

Vol. 7 2 119-125

Ämneskategorier

Materialteknik

Keramteknik

Styrkeområden

Materialvetenskap

DOI

10.1007/s40069-013-0039-y