STRESS BLOCK PARAMETERS FOR HIGH-STRENGTH CONCRETE MEMBERS

Early spalling of cover concrete has been reported by researchers in high-strength concrete (HSC) column tests. A rational way to incorporate this phenomenon into structural building codes has yet to be introduced. Moreover, use of ACI 318-02 stress block parameters to estimate the strength of HSC columns results in unconservative predictions for moment capacity in some cases. Hence, modification of ACI 318-02 stress block parameters to incorporate early cover spalling in HSC columns is of great significance. With this in mind, experimental results obtained during the course of this research and those available from the literature were used to study the accuracy and conservativeness of the ACI 318-02 stress block parameters. Based on experimental evidence, it was determined to reduce the ultimate compressive strain limit of ACI 318-02 to 0.0025 for HSC members such that the capacity of these members can be evaluated prior to cover spalling. A new set of stress block factors was analytically derived and validated with experimental data.

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  • English

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  • Accession Number: 00963159
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 4 2003 12:00AM