Thermodynamic data

Cemdata
 

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

- New version CEMDATA 18.01 available -

The first version of the cement specific cement database Cemdata was published in 2007-2009. Since then it was updated several times; the last update has been published in 2018 (Lothenbach et al. 2018).

Cemdata18 database has been developed specifically for hydrated Portland, calcium aluminate, calcium sulfoaluminate and blended cements, as well as for alkali-activated materials. It is available in GEMS and PHREEQC computer program formats, and includes thermodynamic properties determined from various experimental data published in recent years. Cemdata18 contains thermodynamic data for common cement hydrates such as C-S-H, AFm and AFt phases, hydrogarnet, hydrotalcite, zeolites, and M-S-H that are valid over temperatures ranging from 0 to at least 100°C. Solid solution models for AFm, AFt, C-S-H, and M-S-H are also included in the Cemdata18 database.

Cemdata18 database in GEM-Selektor v.3 format is compatible with the GEMS version of the PSI/Nagra 12/07 TDB (http://gems.web.psi.ch). As several alternative C-S-H models, as well as two models for hydroxide-hydrotalcite are available (see Lothenbach et al., 2018) the user needs to select the appropriate models during the generation of new projects, as illustrated in Figure 1. The CSHQ and the OH-hydrotalcite with Mg/Al = 2 are well adapted for Portland cement systems (select cemdata, pc, ht and cshq as indicated at the left hand side of Figure 1). For alkali activated binders, the CNASH model has been developed for C-S-H type calcium (alkali) aluminosilicate hydrate gels with lower calcium but higher aluminium and alkali content. An Mg-Al layered double hydroxide model with variable Mg/Al ratio is also available for use in alkali activated cement systems. For alkali activated binders, the selection of cemdata, aam and deselection of pc including  ht and csh is recommended as illustrated at the right hand side of Figure 1.

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Figure 1: Selection of modules of Cemdata18 and related databases in GEM-Selektor to model PC (Portland-cement) systems (left) and to model AAM (alkali-activated materials). For PC systems, one of four alternative solid solution models of C-S-H should be selected; selection of Fe-containing solid solutions (“ss-fe3” module) is also optional. For AAM deselect “pc” and select “aam”.

CEMDATA at 25 °C

At 25 °C the solubility products (KS0) of the CEMDATA 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.

 

CEMDATA 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 CEMDATA data base is compatible with the GEMS default kernel database (GEMS version of Nagra-PSI 01/01 data base). Hence, the CEMDATA files comprise a specific extension to the GEMS kernel data base. A download in GEM-Selektor (Gibbs Energy Minimization) format is available.

 

Download of the GEMS version of CEMDATA

To use the CEMDATA data base in GEMS-PSI package, please download it to your hard disk (use the “alternative CSH model CNASH for PC“ for windows computer and “the alternative CSH model CNASH for Mac“ for Macs) 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:\GEM335) the C:\GEMS335/GEMS3-app/Resources/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 C:\GEMS335/GEMS3-app/Resources /DB.default directory.
  4. Start GEMS and create a new project. In the "Selection of databases..." dialog, select  "psi-nagra" and "3rdparty : cemdata ".  This will link the Cemdata database files as a specific extension to the general PSI/Nagra database.
  5. Select Independent Components to form the system and click "Ok" to proceed as usual.

Further information on the CEMDATA data base see:

 

  • Lothenbach, B., Kulik, D., Matschei, T., Balonis, M., Baquerizo, L., Dilnesa, B.Z., Miron, D.G., Myers, R. (2018) Cemdata18: A chemical thermodynamic database for hydrated Portland cements and alkali-activated materials Cement and Concrete Research, https://doi.org/10.1016/j.cemconres.2018.04.018

Further information on GEMS see:


Download of the PHREEQC version of CEMDATA

CEMDATA data base developed together with the auxiliary information from the Nagra/PSI-Thermodynamic Data Base was converted to PHREEQC-format for temperatures 0-100 °C. The PHREEQC version of CEMDATA18 including the general data from the Nagra/PSI-Thermodynamic Data Base is available here

Please use this link to access the PHREEQC version of CEMDATA07.

Further information on the CEMDATA data base see:
• Lothenbach, B., Kulik, D., Matschei, T., Balonis, M., Baquerizo, L., Dilnesa, B.Z., Miron, D.G., Myers, R. (2018) Cemdata18: A chemical thermodynamic database for hydrated Portland cements and alkali-activated materials Cement and Concrete Research, https://doi.org/10.1016/j.cemconres.2018.04.018

Prof. Dr. Barbara Lothenbach

Prof. Dr. Barbara Lothenbach
Senior Researcher / Projektleiterin / Adjunct Prof. NTNU

Phone: +41 58 765 4788