Materials: High strength concrete and steel, Stress-Strain characteristics and properties. 2 Hours Basic Principles of Prestressing: Fundamentals, Load balancing concept, Stress concept, centre of Thrust. Pre-tensioning and post-tensioning systems, tensioning methods and end anchorages. 4 Hours
Stresses in concrete due to pre-stress and loads, stresses in steel due to loads, Cable profiles.
Various losses encountered in pre-tensioning and post tensioning methods, determination of jacking force.
Deflection of a pre-stressed member – Short term and long term deflections, Elastic deflections under transfer loads and due to different cable profiles. Deflection limits as per IS 1343. Effect of creep on deflection, load verses deflection curve, methods of reducing deflection
Flexure -IS Code recommendations – Ultimate flexural strength of sections.
Shear - IS Code recommendations, shear resistance of sections, shear reinforcement. Limit state of serviceability – control of deflections and cracking.
Transmission of prestress in pretensioned members, transmission length, Anchorage stress in post-tensioned members. Bearing stress and bursting tensile force-stresses in end blocks-Methods, I.S. Code, provision for the design of end block reinforcement.
Design of pre-tensioned and post-tensioned symmetrical and asymmetrical sections. Permissible stress, design of prestressing force and eccentricity, limiting zone of pre-stressing force cable profile.