Flexural Strength Analysis of Prestressed Concrete Members with High Strength Strands

摘要

In recent years, Korean strand manufacturers succeeded in developing 2,160 MPa and 2,400 MParnhigh-strength strands. The current design codes provide an approximate equation for strand stressrnat flexural strength. It is because the accurate evaluation of the strand stress requires arncomplicated nonlinear analysis based on the actual stress-strain relationships. In this study, arnmaterial model for high-strength strands was proposed. Using the model, the strand stress and thernflexural strength of prestressed concrete members were calculated. And then, they wererncompared with the predictions by the current approximation equation. The analytical resultsrnindicated that the approximate equation can cause an error in predicting the strand stress.rnHowever, the approximate equation gave the flexural strengths close to those obtained from thernnonlinear analysis. It resulted from the assumption of equivalent rectangular stress block in therndesign code.