RAM Concept uses the concept of a design strip to link finite element analysis with concrete code rules (see Chapter 22, "Defining Design Strips"). Each design strip’s properties include design system (beam / one-way slab / two-way slab) and the "considered as post-tensioned" option. Design strips contain design cross sections.

You assign each load combination active rule set designs in the load combinations window.

How RAM Concept utilizes rule set designs:

1. Load combinations generate envelopes for resultants (moments, shears, axial forces and torsions).
2. All load combination envelopes with the same rule set design are in turn enveloped. This is a rule set design envelope.
3. For each rule set design envelope, design strips generate rule set design force envelopes.
4. Each design strip determines which code rules are appropriate for each rule set design. Design strip properties impact which particular rules are used.
5. Design and checking rules are applied to the rule set design section envelopes.
6. A design summary envelopes the reinforcement requirements and section status for all rule set design section envelopes.

Example:

The following example describes how RAM Concept selects the ACI 318-02 design rules for a post-tensioned beam with live and wind loadings.

RAM Concept ’s process is as follows:

• The two load combinations generate envelopes for resultants.
• The five active rule set designs (service design, code minimum design, user minimum design, strength design and ductility design) each create envelopes from the load combinations.
• Each rule set design envelope creates a rule set design section envelope.
• The design strip properties of "Structural system: beam" and "consider as post-tensioned" determines the following rules from ACI 318-02 are applicable:
  • Strength Design: rules 18.7.2 (flexural strength) and 11.4 and 11.5 (shear strength) are used with the beam clauses.
  • Minimum Design: rule 18.9.2.
  • Service Design: rules 18.3.3 and 18.4.2 (b).
• These rules are applied to the rule set design section envelopes.
• The reinforcement requirements and section status for all rule set design section envelopes are in turn enveloped for a design summary.