What are the Types of members in Prestressed Structures?

There are three types of members in prestressed concrete

TYPE 1 – Tension is not allowed; Cracking is not allowed.

TYPE 2 – Tension is allowed (within permissible stresses) ; Cracking is not allowed.

TYPE 3 – Tension is allowed; Cracking is allowed within permissible stresses.

Type 3 members are the most economical members because they allow cracking and thus use the elastic property of the materials.

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.

PRE-STRESSED STRUCTURE :

Definition :

The prestressed structure is a structure whose overall integrity property, the stability of the structure and its security mainly depends on prestressing.

Important Note :

The international creation of damped permanent stresses within the structure is mainly for the improvement of its performance under various service conditions.

Basic Type of Prestressing are as given below :

1. The precompression is strongly depended on the self-weight of the structure.
2. The pre-tensioning with high strength embedding tendons.
3. Post-tensioning with high strength bonded or unbonded tendon.

Interesting Point :

• Nowadays, the concept of prestressed structure is mostly employed in the design of various buildings.
• The prestressed concrete concept is also used in the underground structure, TV Towers, Power stations, Floating storage and Offshore facilities, nuclear reaction vessels and numerous bridge systems.