A rectangular pre-tensioned prestressed beam has a width of 300mm, a total depth of 600 mm, and a simply supported span of 16m. Grade 1725 stress relieved prestressing tendons are placed at a constant eccentricity of 130mm. The total area of the tendons, subjected to an effective prestressing force of 637.5 KN, is equal to 650.3 sq.mm. Use Eps = 186 MPa, fc’ = 35 MPa and R = 0.25. It is expected that at the time of transfer, the concrete must have reached 75% of its specified strength. Assume that the maximum moment during service loads is 720 KN-m (due to sustained loads). Note : evaluate the allowable stresses given by the code using an uncracked sections. Calculate the concrete stresses at the critical sections during the initial stage.

A rectangular pre-tensioned prestressed beam has a width of 300mm, a total depth of 600 mm, and a simply supported span of 16m. Grade 1725 stress relieved prestressing tendons are placed at a constant eccentricity of 130mm. The total area of the tendons, subjected to an effective prestressing force of 637.5 KN, is equal to 650.3 sq.mm. Use Eps = 186 MPa, fc’ = 35 MPa and R = 0.25. It is expected that at the time of transfer, the concrete must have reached 75% of its specified strength. Assume that the maximum moment during service loads is 720 KN-m (due to sustained loads). Note : evaluate the allowable stresses given by the code using an uncracked sections. Calculate the concrete stresses at the critical sections during the initial stage.

Principles of Foundation Engineering (MindTap Course List)

8th Edition

ISBN:9781305081550

Author:Braja M. Das

Publisher:Braja M. Das

Chapter15: Braced Cuts

Section: Chapter Questions

Problem 15.5P

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