This zeolite20 database has been developed specifically for cement systems (e.g., degrading cements and alkali-activated cement) and is fully compatible with the Cemdata18 database for Portland, calcium aluminate, calcium sulfoaluminate and blended cements. It is available in GEMS and PHREEQC program formats, and includes thermodynamic properties determined from experimental solubility data at various temperatures. The standard entropy (S0) and heat capacity (Cp0) are determined from either experimental data in both literatures and our works or the additivity method based on elementary (hydr)oxide components.
The zeolite20 database covers phases commonly encountered in cement systems and geochemical environments in the temperature range 0-100 °C and is compatible with the GEMS default kernel database (GEMS version of PSI/Nagra database) and the CEMDATA data. Hence, the zeolite data files comprise a specific extension to the GEMS kernel database.
To use the zeolite database in GEMS-PSI package, please download it to your hard disk and perform the following steps:
- Unzip the downloaded zip file (contains a directory named "zeolite20.default") into a temporary directory, e.g. as /Tempfiles/zeolite20.default
- Find where you have GEMS installed (on Windows, usually under C:\Program Files\GEMS2) the /program/DB.default directory. Under Linux, this may need a root password.
- Copy all files from /Tempfiles/zeolite20.default into the /program/DB.default directory.
- Start GEMS and create a new project. In the "Selection of Independent Components..." dialog, turn on "Kernel(Nagra-PSI)" and "zeolite20". This will link the zeolite database files as a specific extension to the kernel PSI database.
- Select Independent Components to form the system and click "Ok" to proceed as usual.
- If used together with Cemdata18, deactivate in "Phase" the zeolites already included in Cemdata18 database (Chabazite, ZeoliteP, Natrolite, ZeoliteX and ZeoliteY) to avoid including the same solid twice.
The zeolite20 database is also available in PHREEQC format. It shares the same SOLUTION_MASTER_SPECIES and SOLUTION_SPECIES with Cemdata18 database and the PSI/Nagra database (PHREEQC format) and cannot be used independently. The PHREEQC version of the zeolite20 database contains PHASES, which can be added in the input as phases when making PHREEQC calculations. When necessary, please disable the zeolites already included in Cemdata18 database (Chabazite, ZeoliteP, Natrolite, ZeoliteX and ZeoliteY).
Thermodynamic data in zeolite20 for Na-zeolite and Ca-zeolite are described in detail in:
- B. Ma, B. Lothenbach (2020) Synthesis, characterization, and thermodynamic study of selected Na-based zeolites, Cement and Concrete Research, 135, 106111.
- B. Ma, B. Lothenbach (2020) Thermodynamic study of cement/rock interactions using experimentally generated solubility data of zeolites, Cement and Concrete Research, 135, 106149.
Another independent zeolite dataset "zeol19" is available at https://www.nature.com/articles/s41529-019-0106-1 in GEMS format. It is not recommended to use both datasets at the same time, but either one or the other.