B) High span-to-depth ratios
- Larger spans possible with prestressing (bridges, buildings with large column-free spaces)
- Typical values of span-to-depth ratios in slabs are given below.
For the same span, less depth compared to RC member.
- Reduction in self weight
- More esthetic appeal due to slender sections
- More economical sections.
C) Suitable for precast construction The advantages of precast construction are as follows.
- Rapid construction
- Better quality control
- Reduced maintenance
- Suitable for repetitive construction
- Multiple use of formwork
- Reduction of formwork
- Availability of standard shapes.
The following figure shows the common types of precast sections.
Limitations of Prestressing
Although prestressing has advantages, some aspects need to be carefully addressed.
- Prestressing needs skilled technology. Hence, it is not as common as reinforced concrete.
- The use of high strength materials is costly.
- There is additional cost in auxiliary equipments.
- There is need for quality control and inspection.
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