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Title |
Experiment and Strength Analysis of High-Strength RC Columns
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Abstract |
This paper is a part of a research plan aimed at the verification of basic design rules of high-strength concrete columns. A total of 32 column specimens were tested to investigate structural behavior and strength of eccentrically loaded reinforced concrete tied columns. Main variables included in this test program were concrete compressive strength, steel amount, eccentricity, and slenderness ratio. The concrete compressive strength varied from 356kg/㎠ to 951 kg/㎠ and the longitudinal steel ratios were between 1.13% and 5.51%. Test results of column sectional strength are compared with the results of analyses by ACI rectangular stress block, trapezoidal stress block, and modified rectangular stress block. Axial force-moment-curvature analysis is also performed for predicting axial load-moment strength and compared with the test results. The ACI rectangular stress block provides over-estimated column strengths for the lightly reinforced high strength column specimens. The calculated strengths by moment-curvature analysis are highly affected by k3 values of the concrete stress-strain curve. Observed failure mode, concrete ultimate strain, and stress block parameters are discussed.
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