ERRATA: January 2005

Prestressed Concrete Analysis and Design: Fundamentals 2nd Edition, 2004, first printing.

Antoine E. Naaman, University of Michigan ISBN 0-9674939-1-9 LCCN: 2004090275

Visit Techno Press 3000 at www.technopress3000.com; you will be able to download a pdf file of the latest Errata. ERRATA:

1. Page 17, read “Dywidag” instead of “Drywidag” 2. Page 30, sixth line before bottom, read “since” instead of “sincde” 3. Page 49, Table 2.5, forth column, read “in2” and “mm2” instead of “in3” and “mm3” 4. Page 149, Table 4.1, 3rd column, fourth cell, 2nd line, read:

instead of (1 ) (1 )F e A F e Ao c o cZ Zc t c bA A

− −

5. Page 154, 14th line from top, read “Fig. 4.12” instead of “Fig. 4.7” 6. Page 171, mid page, read “Nilson [Ref. 4.14]” instead of “Nilson [Ref. 4.4]” 7. Page 177, Section 4.11.3, 3rd line: read “Fig. 4.20c” instead of “Fig. P4.5” 8. Page 177, Section 4.11.3, second paragraph, second line: add a minus sign to the numerical

values of and ti tsσ σ 9. Page 207, Pb. 4.6, third line: read “Table P4.6 and Fig. P4.6” instead of “Table P4.5 and Fig.

P4.5.”

10. Page 238, first line, read: 1

5 647 7 06 in

0 80a .

c ..β

= = =

11. Page 238, second bullet, read: Compute: 7 06

0 337 20 937e

c ..

d .= =

12. Page 238, third bullet, replace by: Referring to Fig. 5.11c, since 0 337 0 375ec / d . . ,= ≤ the section is tension-controlled and the φ factor is 0.9. Thus: 0 90 391 26 kips-ft.n nM . M .φ = =

13. Page 238, fourth bullet, second line, read 0.337 instead of 0.397 14. Page 245, flow chart, box about half the page, the c equation for flanged section: replace b

by bw in the denominator. 15. Page 267, 3rd line before Eq. (5.57), read: instead of d d d de p e s= =

16. Page 298, Problem 5.6, third line: read instead of 4000 4000 f fci c′ ′= = 17. Page 345, second line from bottom, read x axis instead of y axis.

18. Page 380, about mid-page, in reference to Eq. (6.88). The numerical value of (Tu)min was used instead of Tu. The resulting value of 507.11 to replace 251.75 does not change the inequality or the problem.

19. Page 405, Eq. 7.13a, read instead of tr crI I 20. Page 441, Problem 7.1, first line: read “Go back to problem 4.7 “ (instead of 4.6) 21. Page 441, Figure P 7.3, the flange width should read 28 in instead of 48 in. 22. Page 483, Table 8.8 and 8.9, line (f), second column, read:

instead of Σ∆ ( , ) Σ∆ ( , )pC i j sC i jf t t f t t

23. Page 500, Table 8.13, last column, third raw, replace α by a in the equation for X 24. Page 682, 6th line, read “Fig. 11.11” instead of “Fig. 11.9” 25. Page 691, 2nd line after Eq. 11.12, read “Eq. 11.11” instead of “Eq. 11.10”. 26. Page 699, forth line before bottom, read “Ref. [11.13]” instead of “Ref. [11.20]” 27. Page 735, Fig. 12.3, the last number in the right column should read: 0 12.> 28. Page 727, Problem 11.1, first line: read “Example 11.4” instead of “Example 11.3” 29. Page 925, 17th line from top, read "Table 14.14" instead of "Table 14.13" 30. Page 941, in the 7th line, equation for c, 1β should be 0.75 instead of 0.85. 31. Page 959, title of figure, replace “Figure P14.8” by “Figure P14.9” 32. Page 1000, second paragraph, second line: read “three” instead of “tree”. 33. Page 1053, solution of Pb. 1.3, second line, read 0 0031 instead of 0 0028. .ϕ = ; read

2 23 20 instead of in 3.56 inA .s =

Note: the error on top of page 238 leads to several changes in that page. The problem can be continued neglecting the error, or the attached corrected page 238 can be used for convenience and handed out to students.

238 Naaman – PRESTRESSED CONCRETE ANALYSIS AND DESIGN

1

5 647 7 06 in

0 80a .

c ..β

= = =

• From Eq. (5.16), compute the nominal moment resistance

5 647 5 647

0 918 235 29 20 75 1 2 60 21 52 2

5216 76 kips-in 434 73 kips-ft

n. .

M . . . - . . -

. .

= × + ×

= =

⎛ ⎞ ⎛ ⎞⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠

Note that the same result could have been obtained by using the compression force in the concrete in computing .nM From Eqs. (5.3) and (5.17):

0 918 235 29 20 75 1 2 60 21 5

20 937 in0 918 235 29 1 2 60e

. . . . .d .

. . .

× × + × ×= =

× + ×

5 647

0 85 5 12 5 647 20 937 5216 64 kips-in2

434 72 kips-ft (same as above)

n.

M . . . - .

.

= × × × =

=

⎛ ⎞⎜ ⎟⎝ ⎠

• Compute:

7 06

0 337 20 937e

c ..

d .= =

• Compute design moment by ACI:

Referring to Fig. 5.11c, since 0 337 0 375ec / d . . ,= ≤ the section is tension-controlled and the φ factor is 0.9. Thus: 0 90 391 26 kips-ft.n nM . M .φ = = Note: To illustrate the case of a section in the transition zone, assume 0 397ec / d .= instead of 0 337. . Since 0 375 0 397 0 60e. c / d . . ,≤ = ≤ the value of the φ factor (assuming non-spiral transverse reinforcement) is given by Eq. (5.10) (see also Fig. 5.9b):

0 25 0 25

0 23 0 23 0 860 397e

. .. . .

c / d .φ = + = + =

The design moment resistance acceptable by the code (Section 5.17) is then given by: 0 86 373 86 kips-ftn nM . M .φ = =

• Compute design moment by AASHTO assuming fps is same as computed from ACI Referring to Fig. 5.11d, since 0 337 0 42ec / d . . ,= < the section is under-reinforced according to AASHTO and the value of the φ factor is 1 for prestressed concrete and 0.9 for reinforced concrete. Since the section has combined reinforcement, a value of 0.9 is taken here to be on the safe side. Thus the design moment resistance 0.9 391.26 kips-ft.n nM Mφ = =

The above computations were carried out assuming that the minimum reinforcement criterion is satisfied. Let us confirm this assumption. • Compute the cracking moment from Eq. (5.6):

1152 0 918 148500 8 75 530 3 1152 2349024 lbs-in

288

195 75 kips-ft

crM . . .

.

= × + + × =

=

⎛ ⎞⎜ ⎟⎝ ⎠