Beam Design

The Criteria > Beam Design command is used to define reinforcement and bar selection criteria by which a concrete beam will be designed.

Setting	Description
Reinforcement Tab	The Reinforcement Tab is where bar sizes are selected for longitudinal and transverse reinforcement. This is also where the user can overwrite the default code specified parameters: Max/min bar spacing for longitudinal and transverse bars Top, bottom, and side bar clear cover Max/min longitudinal reinforcement ratio (flexure only) In all cases, if the Code option is selected, the program will calculate the appropriate code specified value. If the Use option is selected, the provided value will be used as long as it is within the code specified limits (when applicable). If the user-specified values are not within the code limits, the code limits will be used (see Chapter 5 for detailed information on the code limits that are used in design). Additionally, on the Reinforcement Tab, the user can select whether or not to allow 2 layers of bars and can specify the cover distance to the (effective) center of top and bottom bars (for either 1 or 2 layers of bars). These values are specified separately for gravity and lateral beams. This information is used to calculate the effective depth of reinforcement for longitudinal and transverse reinforcement. The values can be overwritten on an individual beam basis using the Assign Reinforcement Layout dialog box (see Section 3.8.2).
Bar Selection Tab	The Bar Select Tab is where various parameters are defined to fine-tune the reinforcement selection: Minimum Number of Bars in Beam Top - Used to define the minimum acceptable number of bars in the top of the beam. If bars are required in the top of the beam, there will be at least as many bars in the top of the beam as are specified here. Minimum Number of Bars in Beam Bottom - Used to define the minimum acceptable number of bars in the bottom of the beam. If bars are required in the bottom of the beam, there will be at least as many bars in the bottom of the beam as are specified here. Bar Sizes: Keep all bars in layer the same size - Used to force bars that are in the same layer (top or bottom) to be the same size. Bar Sizes: Adjacent bars may differ in size by # sizes - Used to control the change in bar size for bars in the same layer. For example, if 1 is entered, then only #4, #5, and #6 bars can be placed in an adjacent span to a #5 bar. This option is available only if the option to force all bars in the same layer to be the same size is not selected. Transverse Bars: Segment Length Increment - Used to help in defining design segment dimensions that are rounded off to typical dimensions that an engineer would use or that would be practical for construction. For example, the shear reinforcement in a beam may be divided into three segments with one at either end where the shear is highest and a center segment. The segment length increment identifies the segment size increment. If 6 in is used then the segments will be multiples of 6 in. Transverse Bars: Bar Spacing Increment - Used to define the transverse reinforcement spacing increment so that transverse reinforcement spacing matches office and project standards. This eliminates bar spacing that may be in fractions of inches or spacing increments that are impractical for construction. Transverse Bars: Enforce max stirrup spacing even if stirrups are not required - Selecting this option will force the program to provide beam stirrups at all locations along spans even if they are not required by code. This is useful when the design standard of an organization is to place stirrups at a maximum nominal spacing for all beams and joists, regardless of how small the requirement is. When this option is selected, a user-defined maximum shear bar spacing (see Reinforcement criteria tab) must be specified as shown below. Select bars based on Minimum Bar Area, Minimum Bar Spacing, or Maximum Bar Spacing - Used in selecting the optimization criteria from all the acceptable combinations of bar sizes and spacing. Selection by area will attempt to give the least bar area (see Chapter 5 for a detailed discussion of bar selection method and bias). Bar Selection Bias: Bias Bar Size - Used to specify the range of bar sizes that the engineer prefers to use. Bar Selection Bias: Amount of Bias - Used to specify how much importance the engineer places on the Bar Size selected in Bias Bar Size.
Design Checks Tab	This tab is where Torsional Capacity and Deep Beam checks can be optionally included or excluded. This will remove the check and design warnings for torsional capacity and deep beams from the design process. Also within this tab, the user specifies the desired source of gravity forces on lateral concrete beam members. There are two unique sets of gravity analysis results available for lateral members in RAM Concrete Beam: the analysis performed in RAM Concrete Analysis and that performed in RAM Frame. To aid in understanding the differences between the two sets of results, we review a few fundamental characteristics of each analysis: Ram Frame performs both a gravity and a lateral load analysis. The Ram Frame analysis includes only members designated as lateral. Thus, the stiffness of gravity members is not accounted for in the RAM Frame analysis. Ram Frame uses RAM Gravity to apply the reactions from gravity members to supporting frame members. RAM Frame does not perform skip loading. RAM Concrete Analysis performs only a gravity load distribution and does not deal with lateral forces. RAM Concrete Analysis includes both gravity and lateral members. Thus, the stiffness of gravity members is accounted for in the RAM Concrete Analysis. RAM Concrete Analysis skip loads the live loads to generate a controlling envelope. Note: RAM Concrete Analysis analyzes a single story at a time, fixing columns a story above and below, as described in ACI 318, Section 8.9. RAM Frame analyzes a three dimensional structure. If there is significant drift, rotation, or frame action that results from the application of gravity loads to frame members, it is recommended that the user select Use RAM Frame forces. For more information on each analysis method, see the RAM Concrete Analysis and RAM Frame manuals.

Setting

Description

Reinforcement Tab

The Reinforcement Tab is where bar sizes are selected for longitudinal and transverse reinforcement. This is also where the user can overwrite the default code specified parameters:

Max/min bar spacing for longitudinal and transverse bars
Top, bottom, and side bar clear cover
Max/min longitudinal reinforcement ratio (flexure only)

In all cases, if the Code option is selected, the program will calculate the appropriate code specified value. If the Use option is selected, the provided value will be used as long as it is within the code specified limits (when applicable). If the user-specified values are not within the code limits, the code limits will be used (see Chapter 5 for detailed information on the code limits that are used in design).

Additionally, on the Reinforcement Tab, the user can select whether or not to allow 2 layers of bars and can specify the cover distance to the (effective) center of top and bottom bars (for either 1 or 2 layers of bars). These values are specified separately for gravity and lateral beams. This information is used to calculate the effective depth of reinforcement for longitudinal and transverse reinforcement. The values can be overwritten on an individual beam basis using the Assign Reinforcement Layout dialog box (see Section 3.8.2).

Bar Selection Tab

The Bar Select Tab is where various parameters are defined to fine-tune the reinforcement selection:

Minimum Number of Bars in Beam Top - Used to define the minimum acceptable number of bars in the top of the beam. If bars are required in the top of the beam, there will be at least as many bars in the top of the beam as are specified here.
Minimum Number of Bars in Beam Bottom - Used to define the minimum acceptable number of bars in the bottom of the beam. If bars are required in the bottom of the beam, there will be at least as many bars in the bottom of the beam as are specified here.
Bar Sizes: Keep all bars in layer the same size - Used to force bars that are in the same layer (top or bottom) to be the same size.
Bar Sizes: Adjacent bars may differ in size by # sizes - Used to control the change in bar size for bars in the same layer. For example, if 1 is entered, then only #4, #5, and #6 bars can be placed in an adjacent span to a #5 bar. This option is available only if the option to force all bars in the same layer to be the same size is not selected.
Transverse Bars: Segment Length Increment - Used to help in defining design segment dimensions that are rounded off to typical dimensions that an engineer would use or that would be practical for construction. For example, the shear reinforcement in a beam may be divided into three segments with one at either end where the shear is highest and a center segment. The segment length increment identifies the segment size increment. If 6 in is used then the segments will be multiples of 6 in.
Transverse Bars: Bar Spacing Increment - Used to define the transverse reinforcement spacing increment so that transverse reinforcement spacing matches office and project standards. This eliminates bar spacing that may be in fractions of inches or spacing increments that are impractical for construction.
Transverse Bars: Enforce max stirrup spacing even if stirrups are not required - Selecting this option will force the program to provide beam stirrups at all locations along spans even if they are not required by code. This is useful when the design standard of an organization is to place stirrups at a maximum nominal spacing for all beams and joists, regardless of how small the requirement is. When this option is selected, a user-defined maximum shear bar spacing (see Reinforcement criteria tab) must be specified as shown below.
Select bars based on Minimum Bar Area, Minimum Bar Spacing, or Maximum Bar Spacing - Used in selecting the optimization criteria from all the acceptable combinations of bar sizes and spacing. Selection by area will attempt to give the least bar area (see Chapter 5 for a detailed discussion of bar selection method and bias).
Bar Selection Bias: Bias Bar Size - Used to specify the range of bar sizes that the engineer prefers to use.
Bar Selection Bias: Amount of Bias - Used to specify how much importance the engineer places on the Bar Size selected in Bias Bar Size.

Design Checks Tab

This tab is where Torsional Capacity and Deep Beam checks can be optionally included or excluded. This will remove the check and design warnings for torsional capacity and deep beams from the design process.

Also within this tab, the user specifies the desired source of gravity forces on lateral concrete beam members. There are two unique sets of gravity analysis results available for lateral members in RAM Concrete Beam: the analysis performed in RAM Concrete Analysis and that performed in RAM Frame. To aid in understanding the differences between the two sets of results, we review a few fundamental characteristics of each analysis:

Ram Frame performs both a gravity and a lateral load analysis.
The Ram Frame analysis includes only members designated as lateral. Thus, the stiffness of gravity members is not accounted for in the RAM Frame analysis.
Ram Frame uses RAM Gravity to apply the reactions from gravity members to supporting frame members.
RAM Frame does not perform skip loading.
RAM Concrete Analysis performs only a gravity load distribution and does not deal with lateral forces.
RAM Concrete Analysis includes both gravity and lateral members. Thus, the stiffness of gravity members is accounted for in the RAM Concrete Analysis.
RAM Concrete Analysis skip loads the live loads to generate a controlling envelope.

Note: RAM Concrete Analysis analyzes a single story at a time, fixing columns a story above and below, as described in ACI 318, Section 8.9. RAM Frame analyzes a three dimensional structure. If there is significant drift, rotation, or frame action that results from the application of gravity loads to frame members, it is recommended that the user select Use RAM Frame forces.

For more information on each analysis method, see the RAM Concrete Analysis and RAM Frame manuals.