About User-Specified Minimum Reinforcement Ratios

Each span segment has four user-specified reinforcement ratio values:

• Column Strip Top Reinforcement
• Column Strip Bottom Reinforcement
• Middle Strip Top Reinforcement
• Middle Strip Bottom Reinforcement

A user-specified top reinforcement and bottom reinforcement ratio can also be defined for design sections.

RAM Concept ’s User Minimum Reinforcement rule set uses these values to design reinforcement at each cross section. These values are not included in the reinforcement calculated for other rule sets. For example, the bending strength reinforcement reported in the Strength Rule Set is not in addition to the reinforcement in the User Minimum Reinforcement rule set.

User Minimum Reinforcement Calculations

RAM Concept ’s User Minimum Reinforcement calculations are based on the gross area of the cross section (after trimming) and the user-specified ratios. For example:

columnStripTopAs = (cross section Ac)(column strip top reinforcement ratio)

About Precompression Limits

Each span segment has four user-specified reinforcement ratio values

• Column Strip Max. Precompression
• Column Strip Min. Precompression
• Middle Strip Max. Precompression
• Middle Strip Min. Precompression

A user-specified max and min precompression can also be defined for design sections.

RAM Concept ’s User Minimum Reinforcement rule set uses these values to check if the resulting precompression from post-tensioning is within the specified range. These limits are only checked if the Consider as Post-Tensioned box is checked in the span segment properties.

Precompression Calculations

RAM Concept ’s precompression calculation are based on the following:

• Gross area of the cross section (after trimming)
• Effective tendon force multiplied by the perpendicular vector component of the tendon area intersecting the section

The effective tendon force is calculated using the Precompression Calc option defined in the General tab of the section properties. See General tab for an explanation of the available options.

A design failure is produced if the calculated precompression limit is outside the user-specified max and min precompression range.

Old Files

Pre- RAM Concept 2.0 files require rebuilding of the load combinations and rule sets to have the User Minimum Reinforcement rule set added. See Rebuilding load combinations for further information.