MasterFrame Concrete Building Design -

 Concrete Slab & Wall Design

The Concrete Slab Design module expands the capabilities of MasterFrame and MasterFrame FE by enabling the detailed design of reinforced concrete slabs.

With this module, users can extract critical forces from frame analysis to:

• Define basic reinforcement zones within finite element (FE) slabs
• Design reinforcement for peak stress areas and along strip regions
• Perform punching shear checks at column heads and wall ends
• Use auto-design tools to specify bar sizes and spacing

The Concrete Design module simplifies and improves the accuracy of slab reinforcement design, ensuring a more efficient workflow.

In this tutorial, we’ll focus on designing the first-floor slab only. However, the same principles and steps outlined can be applied to complete the design of the ground floor, second floor, and roof slabs.

Slab Design Defaults Menu

The Defaults menu ⚙️ Default and Auto-Design Settings sets standard design parameters for automatic slab reinforcement design. It allows users to define bar diameters and spacings, which control reinforcement arrangements during auto design. While defaults apply globally, individual designs can modify these settings.

Slab Reinforcement Design Menu

The FE Slab Design module automates the reinforced concrete slab design within an FEA model by categorizing the slab into four calculation sets

1. Basic Region 📄 Basic Regions– Defines the general reinforcement mat for the slab
2. Peak Zones 📄 Peak Zones – Enhances reinforcement in areas of high bending moments, such as column supports.
3. 1. Can either replace or add to basic reinforcement
4. Strips 📄 Strips Zones – Provides reinforcement along linear zones, e.g., column strips.
5. 1. Provide reinforcement in one direction, independent of peak zones
6. Punching Shear 📄 Punching Shear– Checks for punching shear resistance around columns and wall ends.
7. 1. Uses either peak or basic reinforcement but not strips.

Setting Up Slab Reinforcement

We will follow the following Design Workflow

1. Define Basic Region – Initial reinforcement mat.
2. Assign Peak Regions – Target high-stress areas for additional reinforcement.
3. Define Strips – Reinforce along column strips or critical lines.
4. Review Basic Region – Adjust reinforcement after peak/strip zones are assigned.
5. Review Peak & Strip Zones – Modify based on changes in the basic reinforcement.

The module’s flexibility allows customisation, ensuring the most efficient reinforcement layout while maintaining design intent.

Define Basic Reinforcement

1. To define  📄 Basic Regions, select the Floor Slab 
2. Under 'Basic Reinforcement Sets', click 'Add New Item (+)'.
3. Add in the required floor details
4. Under 'Place Current Reinforcement', click 'Select'.
5. Hover over the slab in the Model Area until the outline turns yellow, then click with the left mouse button to select the slab.

The calculation turns blue, indicating warnings for reinforcement in both directions. A clearer overview can be gained by examining these critical areas graphically.

Bottom Reinforcement Requirements

We can now review the unity ratios to identify areas of the slab that require additional reinforcement.

• • •  Under Drawing Options, select Unity to visualise the unity ratios.

• • • In the Value to Draw dropdown, select MR Unity Sag XX to display unity ratios for bottom reinforcement in the X direction.
    • ​The Critical Location will be highlighted on the slab

​3.   Adjust Bottom Reinforcement (Dir. 1 – X)

• Go to Slab Design Inputs → Bottom Bars Dir. 1
• Change the bar diameter from 10mm to 12mm.
• Click Refresh in the Drawing Options tab to update the graphics. 

​4.    Inspect Bottom Reinforcement in the Y Direction

• • •  In Value to Draw, choose MR Unity Sag YY to review the Y direction.
    • The Critical Location will be displayed on the slab

​5.    Adjust Bottom Reinforcement (Dir. 2 – Y)

• • • Go to Slab Design Inputs → Bottom Bars Dir. 2
    • Change the bar diameter from 10mm to 12mm.
    • Again, click Refresh and confirm the changes in the updated unity ratio graphics. As with the X direction, critical zones may remain due to localised peaks, but may be be considered acceptable upon review.

Top Reinforcement Requirements

1.    Enable Unity Ratio Display

• Under Drawing Options, ensure Unity is still selected to visualise the unity ratios.

2.    Inspect Top Reinforcement in the X Direction

• In the Value to Draw dropdown, select MR Unity Hog XX to display unity ratios for top reinforcement in the X direction.

3.    Adjust Top Reinforcement (Dir. 1 – X)

Although these high values are localised, we will increase reinforcement generally to reduce peak zones. We will then assign peak reinforcement directly above the internal columns separately.

• Go to Slab Design Inputs → Top Bars Dir. 1
• Change the bar diameter from 10mm to 12mm.
• Click Refresh in the Drawing Options tab to update the graphics.

4.    Inspect Top Reinforcement in the Y Direction

• In Value to Draw, choose MR Unity Hog YY to review the Y direction.

5.    Adjust Top Reinforcement (Dir. 2 – Y)

• Go to Slab Design Inputs → Top Bars Dir. 2
• Change the bar diameter from 10mm to 12mm.

Again, click Refresh and confirm the changes in the updated unity ratio graphics.

As with the X direction, critical zones may remain due to localised peaks, but may be considered acceptable upon review.

Step 2 - Assign Peak Reinforcement

Internal Columns

Under Slab Reinforcement Type, select 📄 Peak Zones. We will start with the Internal Columns

• Click the Add New Item () button. This will activate Draw Mode
• Hover over one of the internal column nodes until it is highlighted in blue, and left click to assign.
• Enable Add Multiple Mode, the button will turn orange, then click on the top of each of the 4 internal columns to place peak reinforcement at those locations. Click Add Multiple Mode again to exit selection mode.
• Select all 4 peak sets by Ctrl + Left Clicking on each on the set list.
• Rename the peak sets to Internal Column.
• Under Auto Design, click Selected to run the design specifically for those peak regions.

Corner Columns

•  Again, click the Add New Item + button to activate Draw Mode
• Enable Add Multiple Mode, the button will turn orange, then click on the top of each of the 4 corner columns to place peak reinforcement at those locations. Click Add Multiple Mode again to exit selection mode.
• Select all 4 peak sets by Ctrl + Left Clicking on each on the set list, then rename the peak sets to Corner Column.
• Under Auto Design, click Selected to run the design specifically for those peak regions.

 Wall Ends

•  Again, click the Add New Item + button to activate Draw Mode
• Enable Add Multiple Mode, the button will turn orange, then click on the top of each of the 8 wall ends to place peak reinforcement at those locations. Click Add Multiple Mode again to exit selection mode.
•  Select all 8 peak sets by Ctrl + Left Clicking on each on the set list, then rename the peak sets to Wall Ends.
• Under Auto Design, click Selected to run the design specifically for those peak regions.

To refine the dimensions or extents of the peak reinforcement, go to the Geometry dropdown tab within the Options panel and make the necessary adjustments. We will make all Wall End Peak zones 1m both directions

• Change Half Width Dir 1 (m) to 1m
• Change Half Width Dir 2 (m) to 1m

Review Existing Peak Reinforcement

• Switch back to Basic under Slab Reinforcement Type.
• In Drawing Options, use the Value to Draw dropdown to cycle through unity ratios:
• Turn on Draw Values for clarity.
• • Select MR Unity Sag Max to review peak sagging zones.

Step 3 – Assign Strips at Shear Wall Locations 

When in Basic, select MR Unity Hog Max to inspect peak hogging areas.

You’ll observe peak hogging moments along the length of the shear walls. We will add Strip Reinforcement for Hogging Moments not covered by the basic or peak reinforcement.

• Under Slab Reinforcement Type, select Strip📄 Strips Zones.
• Click Add (), then hover over the slab, click once the slab outline highlights yellow to select it.
• Rename the new strip to Shear Wall Strip
• Click Draw
• Clicking on the start and end nodes of the wall along Gridline 1 to define the strip.
• In the Inputs tab, under Bars, set the Bar Orientation to Perpendicular.
• Change the bar layout to 12mm bars at 200mm centres (12s @ 200).

Copying the Strip Reinforcement to Gridline 4

1.    Under Slab Reinforcement Type > Strip. click Copy.

2.    Hover over the parent FE Surface (the slab), and click once it highlights yellow to select.

3.    Click Draw, then select the nodes at GL C and GL B along Gridline 4.

Group and Design the Shear Wall Strips

1.    Select all the newly created strip reinforcements at the shear walls.

2.    Rename the group as "Shear Wall Strip".

3.    Click Selected under Do Auto Design to automatically design the selected strips.

Review the Updated Unity Ratios

1.    Return to the Basic tab under Slab Reinforcement Type.

2.    In Value to Draw, choose MR Unity Hog Max.

3.    Click Refresh to view the updated hogging moment unity ratios across the slab.

Punching Shear Reinforcement Checks

Apply FE Shear Forces Design Force Method to Column Heads

For models with columns included, the software will use the column dimensions when determining the punching shear perimeters, as long as the ‘Slab to outer Column Face’ option is set to Yes.

Reinforcement Review and Rationalisation