Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 25
25
Table 14. Ratio of measured to computed
capacities.
Method
Specimen
fy = 100 ksi Mast Eq. Ramberg-Osgood
F1 1.47 1.12 1.07
F2 1.31 1.11 1.08
F3 1.54 1.08 1.01
F4 1.37 1.08 1.02
F5 1.35 1.19 1.14
F6 1.44 1.06 0.991
clearly demonstrate that the specimens reached and exceeded
the target strains.
Figure 8. Crack patterns and curvature in Specimen F4 Two strain gages were bonded to the concrete surface at the
immediately prior to failure. midspan (i.e., in the constant moment region) to measure
the compressive strain. The average strain was used to assess
the performance of the specimens. The ratio of the peak
strain to the target design strain is summarized in Table 15.
The specimens developed a strain of at least 1.9 times larger
than their target values prior to failure. At failure, the con-
crete strain (tabulated in Table 15) ranged from 0.0025 to
0.0039 with an average value of 0.0033. The selection of a
maximum concrete strain of 0.003 in a compatibility analysis
of members reinforced with high-strength A1035 is rational.
2.3.5 Summary and Recommendations
Considering the magnitudes of the strains in the longitu-
dinal bars and concrete, the specimens performed adequately
and met the design objective. The proposed strain limits of
t = 0.008 or higher for tension-controlled behavior and t =
(a) Specimens F1, F2, F3 0.004 for compression-controlled are appropriate. Moreover,
well-established strain compatibility analysis techniques can
(b) Specimens F4, F5, and F6
Figure 9. Load--midspan deflection.
Figure 10. Measured and computed load-deflection
relationships.
