Prestressed Concrete is an
architectural and structural material possessing great strength.
The unique characteristics of prestressed concrete allow
predetermined, engineering stresses to be placed in members to
counteract stresses that occur when the unit is subjected to
service loads. This is accomplished by combining the the best
properties of two quality materials: high strength concrete for
compression and high tensile strength steel strands for tension.
Actually, prestressing is
quite simple. High tensile strands are stretched between abutments
at each end of long casting beds. Concrete is then poured into the
forms encasing the strands. As the concrete sets, it bonds to the
tensioned steel. When the concrete reaches a specific strength,
the strands are released from the abutments. This compresses the
concrete, arches the member, and creates a built in resistance to