Tutorial - Calculate the cement hydrates assemblage and pore water composition


Description

Calculate the hydrates assemblage and pore water composition of the hydration of 100 g CEM-I with a water/cement ratio of 0.5 and at a temperature of 25°C. The CEM I oxide composition is taken from the Lothenbach and Winnefeld (2006) (their table 1). Calculations are done in the Ca-Si-Al/Fe-S-Mg-C-Na-K system.


You will learn to

Start a simulation from a template in a module


Template - Hydrates_00_General


Depends on

Tutorial - Create Managed Project with Cement Module


Step 1 – Create simulation from template for the calculation of the hydrates assemblages

Go to Project Manager

Select the project in the bottom panel

Go to Templates tab in the top panel

Select the template “Hydrates_00_general” (See Hydrates_00_General)

Click the “Create new from template” button

The Metadata dialogue window opens.

Define the name of the simulation (CEM I)

Click OK

The Project Manager is active again. 

Select the simulation (CEM I) and click Select

Step 2 – Define the problem

Only information in the input tables needs to be changed if values are different from the default values. All instructions and data are included in the simulation via the template.

Go to the Global Definitions input tab

Go to the Global Variables

The template consists of two tabs: “Cement Model” and “Cement Recipe” to, respectively, select the cement model and define the cement mixture.

Go to the Cement Model tab (See ModuleCement_Input_01_ModelSystem)


The first group “Cement System" defines which elements are to be considered in the calculations. Selection is done via the drop down menu for the variable "Cement::Model::System$" (See Group - Cement System)


Select system 17 from the drop down menu. Note that this system also contains Cl but is neglected in this tutorial (no Cl in the clinker composition)

The second group “Model Options” allows to select some specific minerals to be included or excluded from the models – default selections are used in this tutorial (See Group - Model Options).


Go to the Cement Recipe tab (See ModuleCement_Input_02_Recipe)


The tab contains several groups - for this tutorial, only the first ("Recipe") and third ("OPC Clinker") are of interest.

The group “Recipe” defines the temperature (°C), the water/cement ratio (-) and the amount of cement (g) (See Group - Recipe).

The group “OPC Clinker” defines the OPC clinker in the mixture (See Group - OPC Clinker).

The first variable ("Cement::Clinker::Reference$") defines the clinker composition in terms of oxide. The drop down list is linked to the data block "OPC" in which the weight percentages of the different oxides are defined.


Go to DataBlock

Select OPC data block in the top panel. The records in that data block are shown in the bottom panel.


For each of the cement constituents (OPC and SCMs), a data table is available. In each of these data table, an oxide composition is given by default (see example for OPC). The indicator in the column Name is used in the dropdown list for the record "Cement::Clinker::Reference$" in the group "Cement::Clinker::Reference$". The reference to the oxide composition is listed in the Info tab. Other compositions can be added (See Tutorial - Adapt oxide composition of OPC clinker).


Run the problem

Step 3 – Check the output

Go to phreeqc.out file

Go to Outline tab

Go to Reading input data for simulation 4 -> Beginning of batch-reaction calculation


Note first that there are warnings. This is because Cl-containing hydrates are in the hydrate assemblage (due to the selection of system 17), but there is no Cl in the input.

The output file gives the standard phreeqc output related to a batch reaction calculation. All geochemical information can be obtained from this file. The template also produces a special output file with the most important information for the cement system.


Go to the Data File output workspace  

Click Open Data File

Open the file “Cement_Hydration_1001.out”

Click View options

Select Text View        

In this view, you find information on the cement recipe, the oxide composition, the hydrated phases and the pore water composition, calculated volumes, and information on solid solution composition

END Calculate the cement hydrates assemblage and pore water composition