The determination of Rebar Intensity values is essential for Slab Design, particularly in areas where columns and shear walls intersect with the slab.
The previous page provides the calculation details for Rebar Intensity, while this page lists the individual operations conducted during the calculation process.
Navigate to Slab Result in the BDS tree view and select the relevant floor. Make the following settings.
Direction: Direction 1
Result Case: 1.2D + 1.6L
Type: TopRebarArea
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The direction we want to look at is Direction 1. Set the result case to "1.2D + 1.6L", which we think is the most critical case.
The result type should be Top Rebar Area.
The yellow rectangles surrounding the columns represent the density rectangles. For a more detailed explanation, please follow this link: [Top Slab Reinforcements]. This link will provide you with a comprehensive explanation and further information regarding the density rectangles associated with the columns.
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In order to perform the calculation, we need to specify a column. Let's select column C2, which corresponds to the upper left corner column.
Now, let's proceed to the results observed on the CAD side.
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As per the CAD results for column C2, we can observe 3 Top Rebar Area result strips. To determine the reinforcement design value of the C2 column, we need to draw lines between the strips in the Slab Design section and perform manual calculations.
For this purpose, we need to draw lines each strip that extends to the Slab edge. The length of the area scanned by the strip is measured from the middle distance to the middle distance of the drawn lines. It is important to note that only the distances within the yellow rectangle (density square) are considered as the scanned area.
This process allows you to calculate the impact of the strip, read as a unit distance, on the overall design. Based on the provided screenshot, it is evident that Strip 2 (Value=0.7319 in²/ft) scans an area measuring 16,875 inches.
Rebar Intensity (Area/Unit Width) | ||
Layer | Analysis Source | Column |
1st | Aecbolt | C2 |
Distance (in) | Strip Area (in^2/ft) | Result |
17.625 in | 0.8025 | 14.14 |
16.875 in | 0.7319 | 12.35 |
4 in | 0.3069 | 1.23 |
Total = 38.5 in | Total = 27.72 | |
Required Intensity → | 27.72 / 38.5 = → | 0.720 (in^2/ft) |
The "Required Intensity" value that was calculated above is utilized for Slab Design in BDS. Using this value, the reinforcement calculation for the slab area that covers the C2 column can be performed.
To access the Slab Design section, please navigate to the BDS tree view and select the relevant floor (in this case, the 5th floor).
Next, navigate to the "Top Reinforcements" section and select the "Column Strip Reinforcements" option. From here, you can compare the required value with the rebar area values obtained from the Slab analysis.
By clicking on the "Compare Required Rebar Area" button, the value that appears for the 1st Layer of the C2 column under the "Aecbolt Results" section should be the same as the value we found earlier.
With the obtained value for the reinforcement calculation of the slab area covering the C2 column, you can proceed with the analysis.
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What does "Required Intensity" mean? How would you define "Provide Intensity"? And what is the connection between these two concepts?
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Why is the value different between Aecbolt Results and Required Intensity?
Answer: Punching Flexural rebar increase
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Why is the Safe Required Intensity value different from the Aecbolt Required Intensity value?
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I want to design Slab with only Safe Results or only Aecbolt results. Is it possible?
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