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Structural Concrete - Hassoun

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Problems 785<br />

b. Locate the tendons to satisfy these limits using straight horizontal tendons within the middle third<br />

of the span.<br />

c. Check the limiting values of the prestressing force at transfer.<br />

19.7 For the girder of Problem 19.6:<br />

a. Harp some of the tendons at one-third points, and draw sections at midspan and at the end of the<br />

beam showing the distribution of tendons.<br />

b. Revise the prestress losses, taking into consideration the variation of the eccentricity, e, along<br />

the beam.<br />

c. Check the factored moment capacity of the section at midspan.<br />

d. Determine the cracking moment.<br />

19.8 For the girder of Problem 19.6:<br />

a. Calculate the camber at transfer.<br />

b. Calculate the immediate deflection at service load.<br />

19.9 For the girder of Problem 19.6, determine the shear capacity of the section and calculate the necessary<br />

web reinforcement.<br />

19.10 Determine the nominal moment capacity, M n , of a pretensioned concrete beam that has the cross section<br />

shown in Fig. 19.15. Given: f ′ c = 5ksi, f pu = 270 psi, f se = 160 ksi, and A se = 2.88 in2 .<br />

Figure 19.15 Problem 19.10.

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