In addition, there are advantages to be gained by prestressing when conditions are favorable to its use.
Following additional advantages due to prestressing have been claimed, when prestressed concrete is used.
The size or dimensions of structural members are reduced, which may increase the clearances or reduce storey heights.
It permits the use of large spans (greater than 30 m) with shallow members, even when heavy load are encountered.
In addition to general advantages, such as excellent fire resistance, low maintenance costs, elegance, high corrosion-resistance, adaptability etc, the prestressed concrete is found to sustain the effects of impact or shock and vibrations.
Because of smaller loads due to smaller dimensions being used, there is considerable saving cost of supporting members and foundations.
The prestressing technique has eliminated the weakness of concrete in tension and hence crack free members of structure are obtained.
Because of better material (i.e. controlled concrete and high tension steel) being used and nullifying the effect of dead loads, smaller deflections are caused.
Disadvantages of Prestressed Concrete
The following are among the advantages of using prestressed concrete.
The unit cost of high strength materials being used is higher.
Extra initial cost is incurred due to use of prestressing equipment and its installation.
Extra labour cost for prestressing is also there.
Prestressing is uneconomical for short spans and light loads.