Pre-stressed concrete is a form of concrete used in construction. It is substantially prestressed during production, in a manner that strengthens it against tensile forces which will exist when in service. According to the construction methods there are two kinds of prestressed concrete :- - Pre-tensioned concrete - Bonded Post-tensioned concrete - Unbonded Post-tensioned concrete The three types of members in prestressed concrete are as follows:- 1. Neither allowing tension nor crack. 2. Allowing tension within permissible stress but cracking is not allowed. 3. Tension and crack both are allowed but within permissible stress.

Terry Collins
Sustainability consultant