The general bending ory by thin curved shells is governed by a differential equation of eighth order involving main shell parameters and deformations and solution based on simplifying approximations have been developed by several investigators and a comparative analysis of various analytical approximations.

The concrete shell roofs have been widely used to cover large floor spaces of industrial structures and y are generally preferred to or structural forms as y use a minimum amount of materials yielding maximum structural advantage, cross section being optimally used to resist forces.

The rebound tensile stresses are resisted by effective prestress toger with tensile strength of concrete and hence steel tendons area at yield should have an equal or greater force than prestress plus concrete tensile strength to prevent failure due to low cycle fatigue based on ory and experience Gerwide recommends a minimum tendon area of not less than 0.5 percent of concrete section.

The design of a two way slab supported on all four sides involves computation of bending moment in principal directions of slab and slab may be supported on masonry walls or beams and mayor may not be continuous over supports and transverse loads are resisted by development of two way slab action, resulting in moments in longer and shorter span directions.

The most common method of wire wrapping circular tanks consists of a traction machine, and it is suspended from a trolley which runs along top of tank walls and high tensile wire is drawn through a die while it is wound on tank to achieve designed tension in wire and as a precaution wires are anchored by clips, wall at regular intervals to ensure that in event of wire fracture, winding does not get detached.

Given N_d = 840, f_min.w = 1, ? = 0.75, t = 120mm,
F_c = N_d/ ?_t+ f_min.w/ ? = 840/0.75×120+ 1/0.75 = 10.75n/mm².

The use of prestressed concrete biological shields for reactor and containment vessels offers many advantages and world wide annual demand for all forms of energy will increase tremendously and numerous electrical power plants will be required to fulfill this stupendous energy requirement and reduced possibility of sudden-bursting failures triggered by local cracking due to high redundancy of tendon concrete system and progressive mode of college is endured so that ample time is available for taking precautionary measures against core melting.

For prestressed concrete pipes, percentage of reinforcement varies between 0.5 and 1 percent and modular ratio between 5 and 6 hence loss to elastic deformation is about 3 to 6 percent of initial stress and in addition to elastic deformation loss, various or losses of stress due to steel relaxation, creep and shrinkage of concrete should also be considered to arrive at an overall estimate of losses of prestress.

The analysis of circular cylindrical shells with prestressed edge beam is more or less similar to Reinforced concrete beam however, effect of prestressing is to be considered in formulating boundary conditions at junction of shell and edge beam and in addition to normal boundary conditions such as zero horizontal displacement and rotation of shell edge, which are also applicable for reinforced concrete shells.

The pretressed concrete pipes are ideally suited for a pressure range of 0.5 to 4n/mm² for this pressure range, while cast iron and steel pipes are not economical, reinforced concrete pipes are not practicable due to ir limited cracking strength and technique of prestressing pipes was first introduced in 1930 and ever since, numerous pipelines have been installed throughout world.