The window is divided into two parts. The upper section lists the concrete classes and steel grades relevant for the design. All materials of the concrete category used for surfaces in RFEM are preset. In the Material Properties section, the properties of the current material, i.e. the material whose table row is selected in the upper section, are displayed.
The table only lists materials that are used in the design. Invalid materials are highlighted in red, modified materials appear blue in color.
Chapter 4.3 of the RFEM manual describes the material properties used for determining the internal forces. The properties of the materials needed for the design are stored in the global material library as well. These values are preset for the Concrete Strength Class and the Reinforcing Steel.
To adjust the units and decimal places of the properties and stresses, select Settings → Units and Decimal Places in the menu (see chapter 8.2).
Material Description
Concrete Strength Class
The concrete materials used in RFEM are preset; materials that are not relevant are hidden.
The strength class can be modified at any time:
click the material in column A, which activates the field.
Then, click the 
button or press the [F7] key to open the list of the strength classes.
The list contains only strength classes that correspond to the design concept of the selected standard.
After the transfer, the design-relevant Material Properties are updated.
As a matter of principle, the material properties cannot be edited in RF-CONCRETE Surfaces.
Reinforcing Steel
In this column, the program presets a steel grade that corresponds to the design concept of the selected standard.
As with the concrete strength class, you can select a different reinforcing steel in the drop-down list:
Click the material in column B to activate the field.
Then, click the button or press the [F7] key to open the list of the reinforcing steels.
As with the concrete strength classes, the list only contains steel grades that are relevant for the selected standard.
After the transfer, the Material Properties are updated.
Material Library
Many materials are stored in a database. To open the [Library], click the button shown on the left, which is available for the concrete strength classes and reinforcing steels at the end of the column.
In the Filter section, the standard-relevant materials are set as a preselection, thus excluding all other categories or standards. You can select the desired concrete strength class or steel grade from the Material to Select list; the properties can be reviewed in the lower section.
Click [OK] or press [↵] to transfer the selected material to window 1.2 of RF-CONCRETE Surfaces.
Chapter 4.3 of the RFEM manual describes how to filter, add, or reorganize materials.