[Solved] The purpose of high tensile strength steel wires in prestres

Concept:

Prestressed concrete is a concrete in which internal stresses of a suitable magnitude and distribution are introduced so that the stresses resulting from external loads are counteracted to a desire degree in reinforced concrete member the prestress is commonly introduced by tensioning the steel reinforcement.

As we know concrete is strong in compression and weak in tension. Therefore, to make concrete strong in tension, we tension the steel reinforcement which in turn induces the compressive tresses in concrete which nullify the tensile stresses already induced in concrete due to external load.

Note:

Tensile strength of high tensile steel is in the range of 1400 to 2000 MPa and if initially stressed up to 1400 MPa, there will be still large stress in the high tensile reinforcement after making deduction for loss of prestress. Therefore high tensile steel is made for prestress concrete.