UPPSC AE (CE) Quiz 26

A concrete beam is prestressed by a cable carrying an initial prestressing force of 600 kN the cross sectional area of the wires in the cable is 300 mm². Take E_s = 210 kN/mm². Then the percentage loss of stress due to shrinkage will be, if the beam is pre tensioned

In a post tensioned beam the cable is subjected to a stress of 1200 N/mm². If the slip at the jacking end is found to be 4 mm. find the percentage loss of stress due to this case if the beam is 25 m long. Take E_s = 210 kN/mm²

Which of the losses occurs under pre-tensioned members

(i) creep of concrete

(ii) shrinkage of concrete

(iii) frictional

(iv) anchorage slip

(v) relaxation of steel

In a prtensioned concrete beam if the initial stress in steel is 800 N/mm², stress in concrete is 6.66 N/mm² and the modulus of elasticity of steel and concrete are 210 and 35 kN/mm² respectively. Estimate the percentage loss of stress in steel due to elastic deformation of concrete.

Consider following losses in a prestressed beam

1. Elastic shortening

2. Friction

3. Creep

4. Shrinkage

5. Relaxation

Time dependent losses is/are:

What is the value of residual shrinkage strain for post tensioned member if age of concrete at transfer is 14 days.

Given fig.

The creep losses are generally taken as ______ of initial prestressing force.

The loss of stress in steel due to elastic shortening or deformation is

Consider the statements for a pre tensioned beam

1) There is no loss due to anchorage slip and shrinkage of concrete.

2) There will be no loss if all wires are simultaneously tensioned.