Book contents
- Frontmatter
- Dedication
- Contents
- Preface to the first edition
- Preface to the second edition
- Acknowledgements
- Notation
- Acronyms and abbreviations
- Part 1 Reinforced concrete
- Part 2 Prestressed concrete
- 12 Introduction to prestressed concrete
- 13 Critical stress state analysis of beams
- 14 Critical stress state design of beams
- 15 Ultimate strength analysis of beams
- 16 End blocks for prestressing anchorages
- Appendix A Elastic neutral axis
- Appendix B Critical shear perimeter
- Appendix C Strut-and-tie modelling of concrete structures
- Appendix D Australian Standard precast prestressed concrete bridge girder sections
- References
- Index
14 - Critical stress state design of beams
from Part 2 - Prestressed concrete
- Frontmatter
- Dedication
- Contents
- Preface to the first edition
- Preface to the second edition
- Acknowledgements
- Notation
- Acronyms and abbreviations
- Part 1 Reinforced concrete
- Part 2 Prestressed concrete
- 12 Introduction to prestressed concrete
- 13 Critical stress state analysis of beams
- 14 Critical stress state design of beams
- 15 Ultimate strength analysis of beams
- 16 End blocks for prestressing anchorages
- Appendix A Elastic neutral axis
- Appendix B Critical shear perimeter
- Appendix C Strut-and-tie modelling of concrete structures
- Appendix D Australian Standard precast prestressed concrete bridge girder sections
- References
- Index
Summary
DESIGN CONSIDERATIONS
In the bending design of prestressed members in general, and of beams in particular, the process below should be followed:
Critical stress state (CSS) criteria must be satisfied at all stages of the life of the beam (i.e. at transfer, during handling, during construction, under service load conditions and after losses have occurred).
If applicable, shear and torsion must be designed for and the CSS design modified if necessary (see Clauses 8.2–8.4 of AS 3600-2009 [the Standard]).
The design must be checked for adequacy under ultimate load conditions (see Clause 8.1 of the Standard).
End-block stresses must be estimated and reinforcement provided (Clause 12.5 of the Standard).
Deflections must be assessed and kept within acceptable limits (see Clause 8.5 of the Standard).
There are other general design requirements that have to be met. including durability (Section 4 of the Standard), fire resistance (Section 5), material properties (Section 3), and other serviceability considerations including crack control (for partially prestressed beams only) and vibration (Clause 9.5). For cracked partially prestressed beams, Equations 4.7(1) and (2) respectively may be used to estimate the average and maximum crack widths.
- Type
- Chapter
- Information
- Reinforced and Prestressed ConcreteAnalysis and Design with Emphasis on Application of AS3600-2009, pp. 412 - 433Publisher: Cambridge University PressPrint publication year: 2013