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CemGEMS web app tutorial

Level Expert

Advanced work with cement recipes, results and processes

Most of work in CemGEMS goes into the input cement recipe, which is a combination of materials (clinker, SCM, water, salts, etc.) and their constituents (alite C3S, belite C2S, ...; silica fume SF, slag GGBFS, limestone, ...).

In order to create a new recipe document, the user can choose one of 10 cement types and one of 2 data types, which results in loading one of 20 cement recipe templates, to be saved under the new recipe name and to be examined, modified or re-arranged by the user. These templates were initially prepared by CemGEMS developers using the data collected and recommended by top experts in cement chemistry (see more about recipe templates here). Even an expert would need 4 to 8 work hours to collect the data, prepare and check a valid cement recipe (template). For a student, it can be difficult to find out what data can be trusted and what not, hence this time could be much longer.

Even though any recipe created from a template can be immediately "equilibrated" to obtain a quite reasonable partially hydrated phase assemblage at 20 deg.C and 28 days reaction time, this is just a starting point of the real work. Easy and flexible ways of recipe modification to a desired state and composition are absolutely essential for the usability of CemGEMS. Such recipe modifications can be done in several alternative ways.

  • Editing recipe data in tree-like tables directly (e.g. properties or formulae compositions of constituents; properties and composition of materials in terms of quantities of constituents or of a shortcut formula list; properties of the whole recipe or its chemical composition given in a shortcut formula list).

  • Using jsoneditor to duplicate or delete formulae, constituents, materials or even recipes in the recipe JSON document (see below);

  • Using the phaseAliases table (only in the Expert view) to suppress/allow some hydrated phases, and to edit aliases of GEMS phase names to be shown in tree-like tables of equilibrated part of the results, in plot legends and frames.

Editing properties in the recipe input

After creating a new recipe based upon one of recipe templates, the user can modify its overall properties such as temperature (0 to 99 C), pressure (1 to 101 bar), or water-binder ratio (W/B_ratio between 0 and 1.0). At the level of the whole recipe, the total Quantity can be changed, if needed; at the level of materials, their relative Quantity values define the addition of water and the composition of blended cement; at the level of constituents, their relative Quantity values can be changed along with the ReactExt (degree of reaction) value. Clicking the Equilibrate button will show the effect of changes upon the hydrated state of cement.


Note that, if Quantity values are given in %mass or %mol units and their sum for the overarching object is not equal to 100%, the values will be automatically rescaled to 100% (first visible after Equilibrate). If achieved changes and the resulting hydrated state needs to ba saved before further changes, then the recipe should be cloned into a new one, which will be modified further.

Simple and efficient access to the inputs via the tree-like table is sufficient in most cases. However, an expert may need to introduce more clinker constituents or some SCMs or even materials, or shortcut lists of chemical formulae that were not available in any of the provided recipe templates. This can be done by invoking the jsoneditor widget by clicking on a pencil-like icon to the left of the object name. Refer to a detailed page "Reshaping recipes using jsoneditor" in this tutorial.

Adjusting the GEMS equilibrated part using phaseAliases

Using the phaseAliases table, the user can edit aliases of GEMS equilibrated phase names and/or block/allow some phases from appearing in the equilibrated part mass balance. This table is only available in the "Expert" view, by clicking on a triangle near "phasesAliases" entry, located just before "outputResults" one. Reload the web page if after selecting the "Expert" view, the "phasesAliases" entry is not visible. Further details are provided in the phases-aliases tutorial page.

Fine-tuning process documents

Process definitions can be viewed/edited by invoking the jsoneditor widget by clicking on a pencil-like icon to the left of the process definition name. Most common reasons include the need to edit the process name or comment (title); to change the range or stepping of the control variable; or to add one more InputSpan for additional controls on stepwise changes in the recipe. See details about available process templates in the process templates tutorial page.

Fine-tuning plot documents

Plot definitions can be viewed/edited by invoking the jsoneditor widget by clicking on a pencil-like icon to the left of the plot name. Most common reasons include the need to edit plot- or axis names; choose the axis scales; or change the color and/or the order of items in the legend. See details about plot templates can be found in the plot templates tutorial page.

Last update: June 8, 2020