Sr.No	Pretensioning	Post-tensioning
1.	Pretension is the technique in which we are imparting tension in strands before placing the concrete.	Post tensioning is done by forming a duct in which strands are pulled (tensioned) after the concrete gains it’s full strength.
2.	Small sections are constructed.	Size of a member is not limited. Heavy long span bridges can be constructed by using this technique.
3.	Loss of strength is above 17%	In post tension loss of strength is not more than 15%
4.	This method is done due to bonding between concrete and steel.	This is developed due to bearing.
5.	It is cheaper because cost of sheathing is not involved in pretensioning	It is costlier because cost of sheathing is required.
6.	It is more durable and reliable	Its durability depends upon the two anchorage mechanism.
7	Small and easy to transport, so it is more popular.	Usually in long sizes. Most are used in have long span bridge construction.
8	It is usually done in factories	It can be done in factory or on the site.
9	The strands are tension before the casting the concrete and in concrete is cast enclosing the tension cables in pretension concrete	plants are enclosed within a duct in the form, and then concrete is casted
10	similar structures are prepared in pre-tensioning concrete	Products are changed according to the structure in case of post-tensioned concrete

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Post time: Jul-15-2021