Thermodynamic data for hydrated solids in Portland cement system (CaO-Al₂O₃-SiO₂-CaSO₄-CaCO₃-Fe₂O₃-MgO-H₂O)

A recent cement specific cement database was published in 2007-2009 and based on work carried out at Empa (Lothenbach et al., 2008; Möschner et al. 2008, 2009; Schmidt et al. 2008) and a PhD carried out both at the University of Aberdeen and at Empa (Matschei et al, 2008). The CEMDATA2007 contains thermodynamic data (solubility product, Gibbs free energy, enthalpy, entropy, heat capacity and molecular volume) for a number of cement phases. Solubility data have been generally calculated based on a critical review of the available experimental data and on additional experiments to derive missing data or to verify the existing data. In addition, some data were estimated based on structural analogues. Where necessary, additional solubility data were measured in a range of temperatures between 0 and 100 °C. The resulting data base CEMDATA2007 (link zu CEMDATA07.1_list.pdf) covers hydrates commonly encountered in Portland cement systems in the temperature range 0-100 °C, including C-S-H, hydrogarnet, hydrotalcite, AFm and AFt phases and their solid solutions.

CEMDATA07 contains thermodynamic data for solids found in Portland cement systems, evaluated as described in several publications. Its applicability to Portland cement systems has been investigated in a number of studies.
In order to model other systems, e.g. blended cements, cement degradation in contact with clay, or sorption of metals in cement matrix, the CEMDATA must be critically evaluated and extended with additional pure solids and/or solid solutions. First studies with involving blast furnace slags and calcium sulfoaluminate cements have been published.

CEMDATA07 at 25 °C

At 25 °C the solubility products (K_S0) of the CEMDATA07 data set is fully consistent with the thermodynamic data for aqueous species, gases, and common minerals such as portlandite or gypsum, provided in the Nagra/PSI-Thermodynamic Data Base (Hummel et al., 2002) and can be used together with the Nagra/PSI TDB in any thermodynamic modelling software.

CEMDATA07 at 0-100 °C

The CEMDATA07 data base covers hydrates commonly encountered in Portland cement systems in the temperature range 0-100 °C. In the temperature range 0-100 °C the CEMDATA07 data base is compatible with the GEMS default kernel database (GEMS version of Nagra-PSI 01/01 data base). Hence, the CEMDATA07 files comprise a specific extension to the GEMS kernel data base. A download of CEMDATA07 in GEM-Selektor (Gibbs Energy Minimization) format is available.

Download of the GEMS version of CEMDATA07

To use the CEMDATA07 data base in GEMS-PSI package, please download it to your hard disk and perform the following steps:

1. Unzip the downloaded zip file (contains a directory named "DB.default") into a temporary directory, e.g. as /Tempfiles/DB.default
2. Find where you have GEMS installed (on Windows, usually under C:\Program Files\GEMS2) the /program/DB.default directory. Remove in that directory all files that contain "specific" as part of the file name (if any such files are present there).  Under Linux, this may need a root password.
3. Copy all files from /Tempfiles/DB.default into the /program/DB.default directory.
4. Start GEMS and create a new project. In the "Selection of Independent Components..." dialog, turn on "Kernel(Nagra-PSI)" and "specific". Tick on "Solutions". This will link the CEMDATA database files as a specific extension to the kernel Nagra-PSI database. "Solutions" will cause GEMS to take Phase records for cement solid solutions, such as C-S-H or ettringite.
5. Select Independent Components to form the system and click "Ok" to proceed as usual.

Tutorial for the use of CEMDATA07 in GEMS

Tutorial I: In November 2007 a workshop on the use of GEMS was co-organised by Empa, University of Aberdeen and PSI. All the lectures given at this workshop can be downloaded:

• 0. Contents
• 1. Introduction to the thermodynamic workshop
• 2. Introduction to thermodynamic modelling
• 3. History and Perspective in GEM Chemical Thermodynamic Modeling
• 4. How to get started
• 5. Data base management
• 6. Hydration of C₃A
• 7. Process simulations
• 8. Model cement composition
• 9. Application examples

During the course a number of tutorial projects have been prepared, which will help you to get started with GEMS and show possible applications. Before copying these project on to your computer, make sure that you have the actual version of GEMS and the cement database properly installed. Then locate the folder “…/GEMS2/projects” on your computer and unzip the ZIP file to that folder. You can also download the GEMS-tutorial installation help as a PDF-file.

• GEMS tutorial projects
• GEMS tutorial installation help file

Tutorial II: A follow-up workshop was hold in June 2010. The presentations can be downloaded below.

• Final programme

Day 1: Overview GEMS, structure, single systems, processes, hydration modelling, solid solutions (B. Lothenbach, T. Matschei)

• Introduction part 1
• Introduction part 2
• How to get started
• Database
• Process simulations
• Hydration modelling
• New version GEMS3

Day 2: User meeting and examples

• Calcium sulphoaluminate cements (F. Winnefeld)
• Influence of BaCO₃ and BaO on the hydration of OPC (P. Carmona)
• Influence of limestone (M. Zajac)
• Ternary cements containing limestone powder and fly ash (K. de Weerdt)
• A thermodynamic database for cement minerals in the context of deep disposals (P. Blanc)
• C-S-H (C. Walker)
• Modeling hydration of cement pastes: a coupled kinetics/thermodynamical approach (E. Guillom)
• Microstructure and thermodynamics (J. Bullard)
• Some thermodynamic calculations related to the formation of thaumasite in concrete (F. Bellmann)
• Sulfate ingress: modelling of different sulfate solutions (W. Kunther)
• Reactive transport modeling of sulfate ingress (A. Idiart)

Released versions

• CEMDATA07.1     10.11.2007
• CEMDATA07.2     14.08.2008

Please download the release news to view recent changes and additions in the database.

REFERENCES

Database development

CEMDATA07

• Möschner, G., Lothenbach, B., Winnefeld, F., Ulrich, A., Figi, R., Kretzschmar R. (2008), Solid solution between Al-ettringite and Fe-ettringite (Ca₆[Al_1-xFe_x(OH)₆]₂(SO₄)₃·26H₂O), Cement and Concrete Research, 39(6), 482-489.
• Schmidt, T., Lothenbach, B., Romer, M., Scrivener, K.L., Rentsch, D., Figi, R. (2008), A thermodynamic and experimental study of the conditions of thaumasite formation, Cement and Concrete Research, 38(3), 337–349.
• Möschner, G., Lothenbach, B., Rose, J., Ulrich, A., Figi, R., Kretzschmar R. (2008), Solubility of Fe-ettringite (Ca₆[Fe(OH)₆]₂(SO₄)₃·26H₂O), Geochimica et Cosmochimica Acta 72(1), 1-18.
• Lothenbach, B., Matschei, T., Möschner, G., Glasser, F. (2008), Thermodynamic modelling of the effect of temperature on the hydration and porosity of Portland cement, Cement and Concrete Research, 38(1), 1-18.
• Matschei, T., Lothenbach, B., Glasser, F. (2007), Thermodynamic properties of Portland cement hydrates in the system CaO-Al₂O₃-SiO₂-CaSO₄-CaCO₃-H₂O, Cement and Concrete Research, 37(10), 1379-1410.
• Lothenbach, B. and Winnefeld, F, (2006), Thermodynamic modelling of the hydration of Portland cement, Cement and Concrete Research 36(2), 209-226.
• Kulik, D.A., Kersten, M. (2002), Aqueous solubility diagrams for cementitious waste stabilization systems: 4. A carbonation model for Zn-doped calcium-silicate hydrate by Gibbs energy minimization, Environ Sci Technol 36, 2926-2931.
• Kulik, D.A., Kersten M. (2001), Aqueous solubility diagrams for cementitious waste stabilization systems: II, End-member stoichiometries of ideal calcium silicates hydrate solid solutions, J Am Ceram Soc 84(12), 3017-3026.

Application to Ordinary Portland cement (OPC)

• Loser, R., Lothenbach, B., Leemann, A., Tuchschmid, M. (2010): Chloride resistance of concrete and its binding capacity – comparison between experimental results and thermodynamic modeling, Cement and Concrete Composites 32(1), 34-42.
• Schmidt, T., Lothenbach, B., Romer, M., Neuenschwander, J., Scrivener, K. (2009): Physical and microstructural aspects of sulfate attack on ordinary and limestone blended Portland cements, Cement and Concrete Research 39(12), 1111-1121.
• Möschner, G., Lothenbach, B., Figi, R., Kretzschmar, R. (2009): Influence of citric acid on the hydration of Portland cement. Cement and Concrete Research  39(4), 275-282.
• Lothenbach, B., Le Saout, G., Gallucci, E., Scrivener, K. (2008), Influence of limestone on the hydration of Portland cements, Cement and Concrete Research 38(6), 848-860.
• Schmidt, T., Lothenbach, B., Romer, M., Scrivener, K.L., Rentsch, D., Figi, R. (2008), A thermodynamic and experimental study of the conditions of thaumasite formation, Cement and Concrete Research, 38(3), 337–349.
• Lothenbach, B., Matschei, T., Möschner, G., Glasser, F. (2008), Thermodynamic modelling of the effect of temperature on the hydration and porosity of Portland cement, Cement and Concrete Research, 38(1), 1-18.
• Matschei, T., Lothenbach, B., Glasser, F. (2007), The role of calcium carbonate in cement hydration, Cement and Concrete Research, 37(4), 551-558.
• Matschei, T., Lothenbach, B., Glasser, F. (2007), The AFm phase in Portland cement, Cement and Concrete Research, 37(2), 118-130
• Lothenbach, B. and Wieland, E. (2006), A thermodynamic approach to the hydration of sulphate-resisting Portland cement, Waste Management, 26(7), 706-719.
• Lothenbach, B. and Winnefeld, F. (2006), Thermodynamic modelling of the hydration of Portland cement, Cement and Concrete Research, 36(2), 209-226.

Application to blended and non-OPC systems

• Winnefeld, F., Lothenbach, B. (2010), Hydration of calcium sulfoaluminate cements – experimental findings and thermodynamic modelling, Cement and Concrete Research, in press.
• Winnefeld, F., Barlag, S. (2010), Calorimetric and thermogravimetric study on the influence of calcium sulfate on the hydration of ye'elimite, Journal of Thermal Analysis and Calorimetry, in press.
• Lothenbach, B., Gruskovnjak A. (2007), Hydration of alkali-activated slag: thermodynamic modelling, Advances in Cement Research, 19(2), 81-92.
• Gruskovnjak, A., Lothenbach, B., Winnefeld, F., Figi, R., Ko, S. C.,  Adler, M., Mäder,U. (2008), Hydration mechanisms of super sulphated slag cement, Cement and Concrete Research, 38(7), 983-992.