RCC Design Test...

As per IS code, the minimum grade of concrete for the design of prestressed concrete structure is:-

The elastic shortening loss in a post-tensioned beam when all the wires are stressed simultaneously if the stress developed in concrete at the level of prestressing cable is 10 MPa and the modular ratio is given as 6.

As per IS 1343, The minimum clear spacing in case of single wires used in pre-tensioning system shall not be less than:

A post tensioned beam 150 mm × 350 mm is prestressed by a parabolic cable with an eccentricity of 50 mm above the centroid at the supports and an eccentricity of 75 mm below the centroid at mid span. Area of cable is 500 mm² and initial prestress is 1000 MPa. Wobbling constant is 0.0015/m, coefficient of friction is 0.55. The percentage of loss of prestress due to friction over 10 m span of beam, if jacking is done from one end is ___