The cross section for a 50-ft-span, rectangular, prestressed beam is shown in the figure. The beamhas no mild reinforcing steel.Design Code:PCI: PCI Design Handbook: Precast and Prestressed Concrete, 7th edition, 2010.Design data for prestressing strands:Low relaxation - 1/2-in. diameterfpu = 270 ksiA = 0.153 in ² per strandStress at release = 175 ksi per strand (after initial losses)If the top fiber stress at the midspan of the beam due to the beam self-weight is 0.65 ksi, the totaltop fiber stress (ksi) at release at midspan is most nearly:Note: Take Tension as negative; Compression as PositiveCENTERLINESOF STRANDS2 in.3 in.18 in.36 in.

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The cross section for a 50-ft-span, rectangular, prestressed beam is shown in the figure. The beam has no mild reinforcing steel. Design Code: PCI: PCI Design Handbook: Precast and Prestressed Concrete, 7th edition, 2010. Design data for prestressing strands: Low relaxation - 1/2-in. diameter fpu = 270 ksi As = 0.153 in ² per strand Stress at release 175 ksi per strand (after initial losses) If the top fiber stress at the midspan of the beam due to the beam self-weight is 0.65 ksi, the total top fiber stress (ksi) at release at midspan is most nearly:

The cross section for a 50-ft-span, rectangular, prestressed beam is shown in the figure. The beam has no mild reinforcing steel. Design Code: PCI: PCI Design Handbook: Precast and Prestressed Concrete, 7th edition, 2010. Design data for prestressing strands: Low relaxation - 1/2-in. diameter fpu = 270 ksi As = 0.153 in ² per strand Stress at release 175 ksi per strand (after initial losses) If the top fiber stress at the midspan of the beam due to the beam self-weight is 0.65 ksi, the total top fiber stress (ksi) at release at midspan is most nearly:

Structural Analysis

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ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

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Problem 1P

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Question

The cross section for a 50-ft-span, rectangular, prestressed beam is shown in the figure. The beam
has no mild reinforcing steel.
Design Code:
PCI: PCI Design Handbook: Precast and Prestressed Concrete, 7th edition, 2010.
Design data for prestressing strands:
Low relaxation - 1/2-in. diameter
fpu = 270 ksi
A = 0.153 in ² per strand
Stress at release = 175 ksi per strand (after initial losses)
If the top fiber stress at the midspan of the beam due to the beam self-weight is 0.65 ksi, the total
top fiber stress (ksi) at release at midspan is most nearly:
Note: Take Tension as negative; Compression as Positive
CENTERLINES
OF STRANDS
2 in.
3 in.
18 in.
36 in.

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