A post-tensioned prestressed concrete beam is stressed by three cables, each with c/s area of 50 mm2 with an initial stress of 900 MPa. If all three cables are straight and located at an eccentricity of 50 mm, consider modular ratio (m) = 6 and stress in concrete at the level of steel (fc) = 5 MPa, than what will be the loss in stress in cables due to elastic shortening if all vales are simultaneously tensioning and anchoring?
1
90 MPa
2
60 MPa
3
30 MPa
4
0