Carbonation of the synthetic calcium silicate hydrate (C-S-H) under different concentrations of CO2: Chemical phases analysis and kinetics
Artikel i vetenskaplig tidskrift, 2020

In this study, the chemical phases analysis and the kinetics of synthetic calcium silicate hydrate (C-S-H) under differentCO2concentrations (natural (0.03%), 3%, 10%, 20%, 50%, 100%) were investigated. For this aim, the scanning electron microscope (SEM) and transmission electron microscope (TEM) were employed for microstructure characterisation. The 29Si magic angle spinning nuclear magnetic resonance (29Si MAS NMR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) coupled with mass spectrometer (MS) were used for characterising the chemical phases before and after carbonation. From the NMR results, it was found that C-S-H would be partly decalcified under the natural condition but completely under the accelerated conditions. Two equations related to the carbonation kinetics under natural and accelerated conditions were proposed respectively. The compositions in decalcified C-S-H were not affected by the CO2 concentration. The XRD analysis showed that vaterite, aragonite and calcite were coexistent after carbonation, which would be transformed to aragonite and calcite with further carbonation. The preferential formation of the allotropic calcium carbonate was not impacted by the concentration of CO2 either. Based on the TGA-MS test, the stoichiometric formula of synthetic C-S-H was determined with CaOâ'™SiO2â'™0.87H2O or Câ Sâ H0.87. In addition, a carbonation kinetics model was proposed to learn the carbonation kinetics of C-S-H carbonated in different CO2 concentrations. The experimental data fitted well with the model. The carbonation kinetics between 3% and 20% CO2 are similar, but different from that under 50% and 100% CO2

Chemical phases


Different CO concentration 2


Synthetic C-S-H


Yong Qiang Li

China Earthquake Administration

Shenzhen University

W. Liu

Shenzhen University

Feng Xing

China Earthquake Administration

Shenzhen University

Shuping Wang

Chongqing University

Luping Tang

Chalmers, Arkitektur och samhällsbyggnadsteknik, Byggnadsteknologi

Shifa Lin

Shenzhen University

Zhijun Dong

ShenZhen Institute of Information Technology

Journal of CO2 Utilization

22129820 (ISSN)

Vol. 35 303-313


Oorganisk kemi


Metallurgi och metalliska material



Mer information

Senast uppdaterat