Flexural behavior of post-tensioned prestressed concrete girders with high-strength strands

• Flexural behaviors of PSC girders with high-strength strands were examined.
• They complied with the current code for flexural strength and ductile behavior.
• Certain specimens slightly exceeded the current limits serviceability.

Recently, high-strength strands with greater yield and tensile strength than ordinary strands have been developed in several countries. However, the influences of the high-strength strands on flexural members and code provisions have not been fully identified to date. In this study, five large post-tensioned girders were tested to investigate the effect of high-strength strands on the flexural behavior based on the concrete compressive strength and the tensile strength of the strands. The test results indicated that the actual flexural behaviors showed good agreement with the predictions of the current code, regardless of the tensile strength of the strands. The specimens exhibited ductile behavior, and the crack patterns were similar in all the specimens. Certain specimens under service load exhibited crack widths and stress in the tensile reinforcements that slightly exceeded the limit in the current codes. Because the excess was not considerable, reasonable crack control can be achieved by the proper arrangement of deformed rebars. However, further study is required to create clear guidelines.