Limitations of Pre-stressing | Pre-stressed Concrete

Limitation of pre-stressing

• More complicated design.
• Small margin of error.
• Pre-stress need skilled technology & labour hence it is not common in reinforced concrete members.
• The use of high strength material is costly.
• There is additional cost in auxiliary equipments (cranes etc).
• There is need for quality control & inspection.

Advantages of Pre-Stressing | Pre-Stressed Concrete

Advantages of Pre-stressing:

The pre-stressing of concrete has several advantages compared to traditional reinforced concrete (RC) without pre-stressing. Following are the advantages of the pre-stressed concrete member over an equivalent RC member.

(1) Section remains un-cracked under service load

1. while it is un-cracked will cause reduction of steel corrosion ultimately increases the durability.
2. Full section is utilized (mean higher amount of inertia) >Higher stiffness > less deflection (improved serviceability).
3. Increase in shear capacity.
4. Suitable for use in pressure vessels & liquid retaining structures.
5. Improved performance under dynamic & fatigue loading.

 (2)  Higher span to depth ratio

1. Larger spans are possible with pre-stressing (bridges. buildings with column free spaces).
2. For the same span less depth is required compared to RC members (reduction in self weight).
3. More aesthetic appeal due to slender section
4. More economical section because of smaller sections & less weight.

 (3) Suitable for pre-cast construction

1. Rapid construction
2. Better quality control
3. Reduced maintenance
4. Suitable for repetitive construction
5. Multiple use of form work
6. Availability of standard shapes

Definition of Pre-Stressed Concrete | Pre-Stressed Concrete

Definition of Pre-Stressed Concrete

Concrete in which internal stresses are intentionally induced in a planned manner such that the stresses resulting from the given external loadings get counteract to a desired degree is called pre-stressed concrete.

In Reinforced concrete members the pre-stress is commonly introduced by tensioning the steel reinforcement (known as tendon)

Tendon: Another name for pre-stressed reinforcement whether wire, bars or strands.

Tendon