Stress and strain of cracked sections - Concrete Structures: Stresses and Deformations - page 263

Lower bounds of strain and curvature can be obtained by assuming that
there is no cracking and using the full area of the concrete section, regardless
of stress value or its sign. The values of axial strain and curvature to be used
in calculation of displacements are derived by interpolation between these
two bounds. How this is done, is the subject of the next chapter.
The procedures of analysis presented in this chapter can be easily pro-
grammed for modern desk calculators or microcomputers and indeed this
should be the route to follow if such computations are to be done repeatedly.
The analysis can also be done by the computer programs SCS and TDA,
described in Appendix G. The programs can be executed on microcomputers
using the software provided on the Internet. The program SCS, Stresses in
Cracked Sections, determines the neutral axis position and calculates the stress
and the strain distributions, ignoring concrete in tension. The program TDA,
Time Dependent Analysis, accounts for the e

ects of creep and shrinkage of
concrete and relaxation of prestressed reinforcement.

ff

Note
1 See Tadros, M.K. (1982), Expedient serviceability analysis of cracked prestressed
concrete beams. Prestressed Concrete Inst. J. , 27 , No. 6, 67-86.