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Thermodynamic Data Bases (TDB)

About Cemdata18 TDB

The Cemdata18 TDB has been developed by Prof. B.Lothenbach and her colleagues at Empa specifically for hydrated Portland, calcium aluminate, calcium sulfoaluminate, phosphate and blended cements, as well as for alkali-activated materials. 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. Using Cemdata18 in GEMS codes requires also using the PSI/Nagra TDB in GEMS version (provided with GEM-Selektor codes) for aqueous species, gases, and common minerals.

About PSI/Nagra TDB

The PSI/Nagra TDB 12/07 dedicated mainly for (radioactive) waste management applications. It consists of three layers of standard-state thermodynamic data:

  • Core Data: cover well-characterized aqueous species, minerals and gases of elements involved in almost any type of speciation calculation. This data has been carefully selected and widely accepted worldwide in various fields of application.

  • Recommended Application Data: well-characterized aqueous species, minerals and gases of elements important in applications such as (a) modeling of ground and surface waters; (b) safety assessments of nuclear waste repositories; and (c) pollution dynamics of chemically toxic substances.

  • Supplemental Data: cover aqueous species and minerals that are less well-characterized than those in the recommended application data, but suitable for scoping calculations and qualitative modeling. Estimates are provided for important species where experimental data are missing or unreliable, but where the omission of estimated constants would lead to obviously unacceptable modeling results.


  • Lothenbach B., Kulik D.A., Matschei T., Balonis M., Baquerizo L., Dilnesa B.Z., Miron G.D., Myers R. (2019). Cemdata18: A chemical thermodynamic database for hydrated Portland cements and alkali-activated materials. Cement and Concrete Research 115, 472-506.
  • Lothenbach, B., Xu, B., Winnefeld, F. (2019). Thermodynamic data for magnesium (potassium) phosphates. Applied Geochemistry 111, 104450 (21 p.).
  • Xu, B., Lothenbach, B., Winnefeld, F. (2020). Influence of wollastonite on hydration and properties of magnesium potassium phosphate cements. Cement and Concrete Research 131, 106012 (21 p.).

Last update: March 8, 2020