5mm diameter wires stress is 1000n/mm², 12 wires of 8mm diameter are stressed to 1200n/mm², f_c = (12x1000x200)/(1000) = 2400kn.

Prestressed pretensioned cored slabs with differ types of cavities are widely used as Floor panels of civil and industrial buildings in erstwhile U.S.S.R Graduck reports that se panels are produced in multiples of 200mm nominal width and lengths from 3.6 to 6.4m and hollow panels of oval cavity type are most economical for larger spans since y contain least volume of concrete as compared to round cavity panels and prestressed concrete ribbons have been used as reinforcement for hollow-cored slabs and se consist of tensioned wires or strands embedded in high grade concrete of star of rectangular cross section.

The developments in sleeper design extending over last three decades has resulted in adoption of different types and prominent types which have been adopted by railways of various countries are: two block sleepers connected by a pipe filled with concrete and containing high tensile bars for compressing concrete in blocks, longitudinal sleepers located continuously under rails and connected by flexible tie bars for gauge retention, beam type single piece prestressed concrete sleepers, which are quite similar to convential wooden type sleepers in shape, length and supporting area and in contrast to two block type, beam type sleepers are flexurally stiff over ir entire length and have additional advantage of providing greater measure of rigidity to track if rails and tightly fastened to sleepers, preventing rotation at seatings and bulking of rails and solid heavy prestressed sleepers have thus made possible adoption of long colded rails, resulting in smooth running and increased safety of vehicles and permanent way.

The design of continuous flat slab floors are similar to those of two way reinforced concrete slabs and a strip of slab of unit width continuous over supports is analyzed as continuous beam and its prestressing results in secondary moments.

Hyperbolic paraboloid shells, grouped under category of doubly curved antielastic sells were first successfully used as roofing units by silberkuhl in germany and parts of one shear hyperboloid units, with a geometric from closely following a circular curve in length(span) direction and hyperbolic curve in direction of width are well suited for mass production since y are ruled surfaces.

According to Indian standard code IS:784, design of prestressed concrete pipes should cover following five stages:
Dull working pressure conforming to limit state of serviceability and first crack stage corresponding to limit state of local damage, in addition, it is also necessary to examine stage of bursting or failure of pipes correspond to limit state of collapse, mainly to ensure a desirable load factor against collapse.

The moment coefficients derived from ultimate load method are generally lower in magnitude than those evaluated from elastic ories thus naturally resulting in savings in reinforcement and however slabs designed by ultimate load method should be checked service loads according to principle of limit state design.

Liquid retaining structures, such as circular pipes, tanks and pressure vessels are admirably suited for circular prestressing and circumferential hoop tension developed due to internal fluid pressure and a reinforced concrete pressure pipes requires a large amount of reinforcement to ensure low tensile stresses resulting in a crack free structure, however, circular prestressing eliminates cracks and provides for an economical use of materials and in addition, prestressing safeguards against shrinkage cracks in liquid retaining structures.

The joint between walls of tank and floor slab may be any one of following three types: fixed base, hinged base, sliding base and ring tension and bending moment developed in walls of tank are mainly influenced by type of connection between walls and base slab and in hinged base is not generally adopted for prestressed concrete and in this type, wall is supported over an annular bearing resting on footing from which base slab is isolated by a joint from which base slab is isolated by a joint contains a compressible filling and in case of large tanks and especially for those which have to store hot liquids a movable or sliding joint is ideal solution to minimize or completely eliminate moments at base of wall.

Expanding cement is places and consolidated and completed until is cured carefully controlled conditions to achieve correct degree of expansion after set and it is important to note that calcium chloride must never be used as an accelerating admixture in prestressed concrete since a number of failures of prestresssed concrete pipes and tanks have been recorded due to phenomenon of chloride corrosion.