<abstract xmlns="http://www.w3.org/1999/xhtml">

Accelerated carbonation of recycled concrete aggregates (RCA) could be an efficient way to reduce the carbon footprint. High CO2-concentration under optimal relative humidity could accelerate the CO2 binding capacity of the hydrated cement paste in the RCA. The latter is the topic of this paper. The study looks into the forced carbonation of crushed cement pastes as a basis to understand the CO2 uptake in relation to various binders containing supplementary cementitious materials (SCM) such as fly ash (FA) and ground granulated blast furnace slag (GGBS). Samples include three cement pastes: ordinary Portland cement, substitution rate of 30 % FA and 50 % GGBS respectively at a water/binder ratio of 0.45. All binders were graded to 0/2, 2/4 and 4/8 mm fraction sizes and preconditioned before exposed to CO2 concentration of 10 % under controlled temperature at 20 °C and 65 % RH. All tested binders presented a high CO2 uptake within the first hours of exposure with clear differences concerning the fraction sizes and the composition. The phase content before and after carbonation was observed by X-ray diffraction and the portlandite and calcite were quantified by thermogravimetric analyses and their derivative curves for fraction size 4/8 mm.
</abstract>

Accelerated carbonation of recycled concrete aggregates (RCA) could be an efficient way to reduce the carbon footprint. High CO2-concentration under optimal relative humidity could accelerate the CO2 binding capacity of the hydrated cement paste in the RCA. The latter is the topic of this paper. The study looks into the forced carbonation of crushed cement pastes as a basis to understand the CO2 uptake in relation to various binders containing supplementary cementitious materials (SCM) such as fly ash (FA) and ground granulated blast furnace slag (GGBS). Samples include three cement pastes: ordinary Portland cement, substitution rate of 30 % FA and 50 % GGBS respectively at a water/binder ratio of 0.45. All binders were graded to 0/2, 2/4 and 4/8 mm fraction sizes and preconditioned before exposed to CO2 concentration of 10 % under controlled temperature at 20 °C and 65 % RH. All tested binders presented a high CO2 uptake within the first hours of exposure with clear differences concerning the fraction sizes and the composition. The phase content before and after carbonation was observed by X-ray diffraction and the portlandite and calcite were quantified by thermogravimetric analyses and their derivative curves for fraction size 4/8 mm.

Accelerated Carbonation of Binders Containing SCM at High CO2 Concentration

University of Borås, RISE Research Institutes of Sweden, Infrastructure and Concrete, Technology, Material Design

Prof., Ph.D. M.Sc. Department R&D Manager and Professor

Ph.D. M.Sc. and Adjunct Professor, Luleå University of Technology

Nordic Concrete Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Accelerated Carbonation of Binders Containing SCM at High CO Concentration

Accelerated carbonation of recycled concrete aggregates (RCA) could be an efficient way to reduce the carbon footprint. High CO2-concentration under optimal...

Accelerated Carbonation of Binders Containing SCM at High CO₂ Concentration

Publié en ligne: 06 janv. 2024

Pages: 1 - 10

Reçu: 31 mars 2023

Accepté: 14 août 2023

DOI: https://doi.org/10.2478/ncr-2023-0004

Mots clés
Accelerated carbonation, SCM, TGA, XRD, Carbon sink

© 2023 Alexander Oliva Rivera et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Accelerated Carbonation of Binders Containing SCM at High CO2 Concentration

Publié en ligne: 06 janv. 2024

Pages: 1 - 10

Reçu: 31 mars 2023

Accepté: 14 août 2023

DOI: https://doi.org/10.2478/ncr-2023-0004

Mots clésAccelerated carbonation, SCM, TGA, XRD, Carbon sink

© 2023 Alexander Oliva Rivera et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Accelerated Carbonation of Binders Containing SCM at High CO₂ Concentration

Mots clés
Accelerated carbonation, SCM, TGA, XRD, Carbon sink