The prestressed concrete cross-section and the simplified section that can be used for the calculations are...

 

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The prestressed concrete cross-section and the simplified section that can be used for the calculations are given below. There are sixteen 0.6 inch diameter (d: 15 mm, area: 140 mm?) seven-wire straight tendons placed at the bottom of the section with 5 cm vertical and horizontal center-to-center spacing (distance from the center of the bottom layer of strands to the bottom surface is also 5 cm). The strands were initially tensioned to 0.8fpk. It was determined that the prestressing loss immediately after the transfer is 7% of fpij, while the long term loss is 20% of fpi. Eç = 33000 MPa, fe = 50 MPa, f = 4 MPa. Use Hognestad concrete model. For prestressing strands, assume an elastic-perfectly plastic behavior with fpk=1700 MPa, E=200000 MPa and an ultimate strain of 0.05. Compute the moment curvature response for the following points: a) Initial stage, zero moment b) First cracking c) Ultimate moment capacity using rectangular stress block 170 cm 170 cm 15 cm 15 cm 22.5 cm 25 cm 75 cm 25 cm 90 cm 15 cm 20 cm 27.5 cm 70 cm 70 cm Actual Section Simplified Section The prestressed concrete cross-section and the simplified section that can be used for the calculations are given below. There are sixteen 0.6 inch diameter (d: 15 mm, area: 140 mm?) seven-wire straight tendons placed at the bottom of the section with 5 cm vertical and horizontal center-to-center spacing (distance from the center of the bottom layer of strands to the bottom surface is also 5 cm). The strands were initially tensioned to 0.8fpk. It was determined that the prestressing loss immediately after the transfer is 7% of fpij, while the long term loss is 20% of fpi. Eç = 33000 MPa, fe = 50 MPa, f = 4 MPa. Use Hognestad concrete model. For prestressing strands, assume an elastic-perfectly plastic behavior with fpk=1700 MPa, E=200000 MPa and an ultimate strain of 0.05. Compute the moment curvature response for the following points: a) Initial stage, zero moment b) First cracking c) Ultimate moment capacity using rectangular stress block 170 cm 170 cm 15 cm 15 cm 22.5 cm 25 cm 75 cm 25 cm 90 cm 15 cm 20 cm 27.5 cm 70 cm 70 cm Actual Section Simplified Section

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ANSWERS To compute the moment curvature response for the given points we need to follow the steps ou... View the full answer