JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Course Objectives

To impart knowledge on basics of prestressing and designing of different

structural elements using Prestressing techniques.

Course Outcomes

The learner will be able to understand the prestressing techniques, design the

various structural elements using Prestressing techniques.

UNIT - I

General Principles of Prestressed Concrete : Pre–tensioning and post – tensioning – Prestressing by straight, concentric, eccentric, bent and parabolic tendons – Different methods and systems of prestressing like Hoyer system, Freyssinet system, Magnel Blaton system – Lee-Mc call system. Losses of Prestress: Loss of prestress in pre-tensioned and post-tensioned members due to various causes like elastic shortening of concrete, shrinkage of concrete, creep of concrete, relaxation of steel, slip in anchorage, bending of member and frictional loss – Analysis of sections for flexure.

UNIT - II

Design of Section for Flexure: Allowable stresses – Elastic design of simple beams having rectangular and I-section for flexure – kern lines – cable profile and cable layout. Design of Sections for Shear: Shear and Principal Stresses – Improving shear resistance by different prestressing techniques – horizontal, sloping and vertical prestressing – Analysis of rectangular and I–beam – Design of shear reinforcement – IS: 1343: 2012 provisions.

UNIT - III

Deflections of Prestressed Concrete Beams : Short term deflections of uncracked members– Prediction of long-time deflections – load – deflection curve for a PSC beam – IS code requirements for max. Deflections.

UNIT - IV

Transfer of Prestress in Pretensioned Members : Transmission of prestressing force by bond – Transmission length – Flexural bond stresses – IS: 1343 : 2012 provisions – Anchorage zone stresses in post tensioned members – stress distribution in End block – Analysis by approximate, Guyon and Magnel methods – Anchorage zone reinforcement.

UNIT - V

Statically Indeterminate Structures : Advantages & disadvantages of continuous PSC beams – Primary and secondary moments – P and C lines – Linear transformation concordant and non- concordant cable profiles – Analysis of continuous beams and simple portal frames (single bay and single story)

TEXT BOOKS:

• 1. Prestressed concrete by Krishna Raju, Tata McGraw Hill Book – Co., New Delhi.
• 2. Prestressed Concrete by K.U. Muthu, et.al, PHI Learning Pvt. Ltd.,

REFERENCES:

• 1. Design of Prestressed Concrete Structures by T.Y. Lin and Burn, John Wiley, New York.
• 2. Prestressed Concrete by N. Rajagopalan, Alpha Science International.
• 3. Prestressed Concrete by S. RamamruthamDhanpatRai& Sons, Delhi.
• 4. IS 1343 -2012 Prestressed Concrete – Code of Practice, Bureau of Indian Standards. M. Tech – I Year – II Sem. (Structural Engg.)