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RC Slab Design

The scope of this calculation module is to design a reinforced concrete slab supported on four sides intended to carry uniformly distributed dead and imposed loads. The slab is designed for one-way or two-way action depending on length to width ratio using the coefficients available from the relevant standards. The section is designed for the resulting moment and shear. For deflection control, minimum span to thickness ratio is calculated.

Standards: British, European.

Features

  • The support conditions at four sides shall be specified as simple or continuous individually. Depending upon the support conditions and length to breadth ratio, program automatically determines the one-way or two-way action and continuity of the slab at supports.
  • For a slab simply supported on all edges, torsional provision at corners can be specified for the design.
  • The deflection ratio is checked for the following options:
  • Simple
  • Continuous
  • For above options, the application uses the span to effective depth ratio for calculation.
  • Program
  • The application automatically detects the suitable conditions based on the slab end conditions defined.
  • User
  • The user can directly enter the span to effective depth ratio.

Design Considerations

  • The application calculates and includes the self-weight of slab for the unit weight specified.
  • Design load factors for live and dead loads shall be specified for the calculation of design moment and shear.
  • For one-way action, moment and shear are calculated based on the longer side end conditions and reinforcement adequacy is checked for sagging and hogging moment in the shorter span direction.
  • For two-way slab design, reinforcement adequacy is checked for hogging and sagging in both directions (shorter and longer span).
  • For two-way slab with all edges simply supported, user can specify torsion provision at the corners.
  • The module checks for allowable shear stress against the design shear stress calculated from the shear coefficients.
  • Deflection ratio of slab is calculated according to the support conditions provided by the user or by the program.

National Standards Available

British Standard

Europe Standard

  • National Annex of several countries such as Europe (Recommended), UK, Finland, Ireland, Malaysia, Norway, Singapore and Sweden are considered.
  • Additionally, an option is provided to define the coefficients directly by the user.

References

  • BS 8110-1:1997 - Structural use of concrete - Part 1: Code of practice for design and construction.
  • EN1992-1-1:2004 - Design of concrete structures - Part 1-1: General rules and rules for buildings.

Revision

  • Ver 1.0 - Original version