Bar Selection Bias
On the Criteria - Beam Design - Bar Selection tab, you can specify the size of bars that are preferred. The amount of bias increases or decreases the critical parameter used in the Bar Selection Method when a bar is not a part of the preferred bar size. The increase in the value is based on how far the bar size is from the preferred bar size. Assuming Medium bar size is selected then a #5 bar set will have double the percent increased compared with a #6 bar because a #5 bar is two bar sizes away from the #7 (medium) bar size. The amount of bias is most effective when minimum reinforcement area is selected.
Bar Selection Example:
Consider an example where the 1.1in2 of flexural reinforcement is required. The following outcomes can be expected based on the user selections:
- Minimum Bar Area, Medium Bar Size and Medium Bias: 2-#7 (1.2in2) is selected over 10-#3 because it is not part of the medium bar size, so its area is increase before comparing it to the 2-#7.
- Minimum Bar Area, Small Bar Size and Medium Bias: 10-#3 (1.1in2) is selected over 2-#7 because it is part of the small bar size and has the smallest bar area of any bar set combination.
- Maximum Bar Spacing, Small Bar Size and Large Bias: 2#7 (1.32in2) will be selected over 3-#6 because even though it is not part of the small bar size its spacing and reinforcement area are considered preferable to 3-#6 because the spacing is larger.