Bissoy.com
Doctors Medicines MCQs Q&A

A concrete beam is post tensioned by a cable carrying an initial stress of 1000n/mm2, the slip at the jacking end was end was observed to be 5mm; modulus of elasticity of steel is 210kn/mm2. Estimate the percentage loss of stress due to anchorage if length of beam is 30m?

A concrete beam is post tensioned by a cable carrying an initial stress of 1000n/mm2, the slip at the jacking end was end was observed to be 5mm; modulus of elasticity of steel is 210kn/mm2. Estimate the percentage loss of stress due to anchorage if length of beam is 30m? Correct Answer 3.5%

Loss of stress due to anchorage slip = (EsΔ/l), For a 30m long beam, loss of stress = (210×103×5)/(30×1000) = 35n/mm2, Loss of stress = 35/1000×100 = 3.5%.

Related Questions

A post tensioned cable of beam 10m long is initially tensioned to a stress of 1000n/mm2 at one end, slope is 1 in 24 tendons curved at each end , area is 600mm2, Es is 210kn/mm2, coefficient of friction between duct and cable is 0.55, friction coefficient for wave effect is 0.0015perm. During anchorage, if there is a slip 3mm at the jacking end, calculate final force?
A prestressed concrete beam, 200mm wide and 300mm deep is prestressed with wires (area is 320mm2) located at a constant eccentricity of 50mm, initial stress of 1000n/mm2, span is 10m. Calculate loss of stress due to friction and slip anchorage of post tensioned beam?(Es = 210kn/mm2, Ec = 35kn/mm2).
Consider the following statements concerning elasticity of concrete 1. Stress-strain behaviour of concrete is a straight line up to 10% of ultimate stress. 2. Strain determination is obtained from tangent modulus. 3. Modulus of elasticity, of concrete is also called as secant modulus. Which of the above statements are correct?
A post tensioned concrete beam of rectangular section 200mm wide and 300mm deep is stressed by a parabolic cable with eccentricity 50mm at centre of span, area is 3×104mm2, initial stress is 1200n/mm2 Find the stress in concrete at the level of steel?
A pre tensioned concrete beam 100mm wide and 300mm deep, initial force of 150kn at an eccentricity of 50mm, moment of inertia is 225×106mm4, initial stress in steel is 400n/mm2, modular ratio is 8. Estimate the percentage loss?
The notification for six different posts - Clerk, PRO, Lecturer, Accountant, Watchman and Principal- are to be released on consecutive Fridays. The schedule of the releasing is to be in accordance with the following conditions: (i) Clerk post must be released a week before the Watchman post. (ii) Lecturer post must not be released immediately after the first release. (iii) PRO post must be released on the Friday following the Friday on which the Principal post is released. (iv) Accountant post must be released on the fifth Friday and should not be immediately preceded by the PRO post. (v) The Watchman post must not be released last. Which of the following notifications will be released immediately after the PRO post?
A post tensioned concrete beam, 100mm wide and 400mm deep is prestressed by three cables, each with a cross sectional area of 50mm2, initial stress of 1200n/mm2. Calculate the stress in concrete at level of steel?
A rectangular concrete beam 360mm deep and 200mm wide, is prestressed by means of fifteen 5mm diameter wires located 65mm from the bottom of the beam and three 5mm wires, located 275mm from top of the beam, initial tension stress is 840n/mm2. Calculate prestressing force?
A post tensioned concrete beam 200mm wide and 450mm deep, of span 10m, initial stress of 840n/mm2 is available in the un jacked end immediately after the anchoring. Find the angle between tangents to the cable at supports?
A pre tensioned beam is prestressed using 5mm diameter wires with an initial stress of 80 percent of the ultimate strength of steel fpu = 1600n/mm2. Calculate average bond stress?