The thickness of concrete in shell is in range of 50-75mm and curved shell segments are connected by cast insitu joints which are prestressed by suitable high tensile cables and transverse directions at modular intervals to achieve integrity of joints resulting in large interrupted space inside shell.

The capacity of such tanks may vary from 400 to nearly 40000m³ and economical dimensional proportions for water tanks as reported by preload engineering company, Newyork and ses tanks are provided with reinforced concrete domes having a thickness ranging from 50-110mm with a prestressed concrete ring beam at junction of cylindrical tank walls and spherical dome.

The structure comprises prestressed concrete folded plates cantilevering on opposite sides from main service complex and long cantilever span can be considered as world record for this type of construction which was chosen to achieve flexibility of lateral expansion without distributing existing facilities.

Practical engineers must be more conceptual than mere perceptual, more creative than mere analytical and more visual than mere mamatical and construction engineers should have wide experience involving several types of structures rar than isolated narrow specialization and expertise and original skill are attained from relentless understanding and practice rar than mere oretical knowledge and good and sound judgment are attained from wide practical experience and often experience comes from bad judgment.

Concrete of uniform quality can be produced only when ingredients are accurately measured for each batch and good specification requires that batching is done by weight rar than by volume weight batching ensures greater accuracy, simplicity and flexibility and specifications require that materials ? cement, aggregates and water measured to an accuracy of + or ? 0.5%.

Twin cantilever folded plate roofs with a central service complex and continuous folded plate roof is stayed by prestressed concrete ties and this type of planning provides and unrestricted clear space of 60-90m on eir side of central service complex and cantilever and folded plate roof complex requires significantly lower quantities of materials like concrete and prestressing cables due to unique feature of structural form.

The various advantage of reducing w/c ratio is as follows:
Increased compressive, flexural and tensile strength, increased density of concrete with lesser voids, increased water tightness, lower absorption of moisture due to less porosity, increased resistance to wearing, better bond between concrete and reinforcement, superior dimensional stability, lesser shrinkage cracks.

An example of application of prestressed concrete in aqueducts in India is Gomati aqueduct having 12 equal spans of 31.8m and structure is designed as a box section of 12.8m by 6.7m and carries a discharge of 357 cumecs and depth of two main prestressed concrete girders is 9.9m and weights as much as 550 tones per girder per span.

Degussa-MBT construction chemicals (INDIA) have developed revolutionary type of admixtures using nano polymers which can be used to bring toger functional groups aimed at targeted performances in concrete and based on nano science.

In case of large floor and roof coverings using prestressed concrete as material, re are several types of structural forms for adoption and some of m are as follows: Tee beam and slab floors, continuous beam and slab floors, coffered or grid floors, flat slab floors, folded plate roofs, shell roofs, spherical domes, trusses and framed roofs, composite construction using prestressed and reinforced concrete.