Patent ID: 8534022

Claim:
A prestressed concrete structure comprising: a hardened concrete body; a reinforcing bar comprising a first end and a second end, at least a portion of the reinforcing bar between the first end and the second end extending at least partially through the hardened concrete body; at least one external thread disposed on the reinforcing bar, the external thread formed from an elongated, nonlinear channel wrapped about a radial surface of the reinforcing bar in a substantially helical fashion, wherein a base portion of the nonlinear channel is disposed substantially against the radial surface of the reinforcing bar and an upstanding portion of the nonlinear channel extends generally orthogonally from the radial surface of the reinforcing bar, and wherein the base portion of the nonlinear channel increases in width along the generally cylindrical rod from the first end to the second end, the at least one external thread operatively engaged with the hardened concrete body; a first lock operatively coupled to a first locked section of the reinforcing bar adjacent to the first end, the first lock being arranged to oppose rotation of the first locked section of the reinforcing bar relative to the hardened concrete body, wherein the first lock is configured to maintain the reinforcing bar in a torsionally stressed condition employing one of: a wrench or a ratchet, such that the at least one external thread maintains a compressive force on the hardened concrete body in a generally axial direction relative to the reinforcing bar; and at least one plate having an internally threaded hole, wherein the plate is embedded in the hardened concrete body and engaged via the internally threaded hole with the at least one external thread of the reinforcing bar such that the at least one external thread maintains axial forces on the plate and the plate maintains compressive forces to the hardened concrete body.