Abstract
In recent years, high strength 7-wire strands that have a 2,400 MPa tensile strength were developed, for which the serviceability check specified in ACI318-14 and KCI 2012 need to be reviewed. The current design codes (KCI 2012 or ACI318-14) permitted that the tensile stress of reinforcing bars at service loads can be assumed as two-thirds of their yield strengths. However, they restricted the net tensile stress of the prestressing strands in Class C prestressed concrete (PSC) members at service loads (∆fps) to be less than 250 MPa regardless of the tensile strengths of prestressing strands. Therefore, in this study, a parametric analysis was conducted on the PSC members reinforced with 2,400 MPa high strength prestressing strands considering the key influential factors on the ∆fps, such as shape and size of section, partial prestressing ratio (PPR), reinforcing index (w), and magnitude of effective prestress (fse). The analysis results showed that the ∆fps is not affected by section size, and decreases in accordance with increasing fse, PPR, and cracking moment to service moment ratio (Mcr/Mservice). Based on the analysis results, a simple design table was suggested to check if the ∆fps satisfies its limitation at the design stages, which does not require any complex iterative calculations for checking ∆fps.
Original language | English |
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Pages (from-to) | 75-82 |
Number of pages | 8 |
Journal | Journal of the Korea Concrete Institute |
Volume | 30 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 1 2018 |
Externally published | Yes |
Keywords
- 2,400 MPa strands
- Non-linear analysis
- Prestresssed concrete
- Serviceability
- Tensile stress
ASJC Scopus subject areas
- Civil and Structural Engineering
- Mechanics of Materials
- Building and Construction
- Materials Science (miscellaneous)