Book contents
- Frontmatter
- Contents
- Preface
- Acknowledgements
- Notation
- Acknowledgements for tables and diagrams
- Acronyms and abbreviations
- Part I Reinforced concrete
- Part II 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 Development of an integrated package for design of reinforced concrete flat plates on personal computer
- Appendix D Strut-and-tie modelling of concrete structures
- Appendix E Australian Standard precast prestressed concrete bridge girder sections
- References
- Index
14 - Critical stress state design of beams
from Part II - Prestressed concrete
- Frontmatter
- Contents
- Preface
- Acknowledgements
- Notation
- Acknowledgements for tables and diagrams
- Acronyms and abbreviations
- Part I Reinforced concrete
- Part II 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 Development of an integrated package for design of reinforced concrete flat plates on personal computer
- Appendix D Strut-and-tie modelling of concrete structures
- Appendix E 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 enumerated 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 condition 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)
In addition, 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).
This chapter mainly presents the CSS approach to bending design or how the first item in the above bulleted list is satisfied. Chapter 15 covers, in some detail, the ultimate strength check for fully and partially prestressed beams (third bullet point). Chapter 16 presents the end-block design for prestressing anchorages. The reader is referred to the Standard for details of the other design considerations listed above. It is worth noting that design topics such as shear, torsion, durability, material properties and crack control for reinforced beams have been discussed in detail in Part I.
- Type
- Chapter
- Information
- Reinforced and Prestressed ConcreteAnalysis and Design with Emphasis on Application of AS3600-2009, pp. 348 - 366Publisher: Cambridge University PressPrint publication year: 2010