편심축력을 받는 고강도 콘크리트 기둥의 거동

Abstract

With increasing use of high strength concrete tied columns in reinforced concrete structure, it is demanded to examine the applicability of the related sections in the current design codes. This experimental study was performed to investigate the behavior of eccentrically loaded high strength concrete columns. Column specimens with concrete strength, 234, 437, 703 kgf/cm2 were tested under monotonically increasing eccentric axial compression. The variables in this test program were the ratio of longitudinal reinforcement, tie configuration, eccentricity, and concrete strength. From a comparison of the results from this test series with both ACI code and canadian code provided, it was concluded as followings.When the test results are compiled with the ACI code provided, flexural dominant zone of experiment is safe in the load moment interaction curve. However, the column specimen, HSQ-E3 with the compressive strength of concrete, 703kgf/㎠, is safe only if the CSA A23.3 code presented is applied. The compressive governing region in the load moment interaction curve of test results dose not give a safety margin as a whole if the ACI code is applied. On the other hand, the resulting experimental curve is close to safe side if MacGregor's Equation is used. Furthermore, the CSA A23.3 code predicted is conservative in the compressive dominant zone. Thus, it is much safer to use the CSA A23.3 code in the estimation of the strength of the reinforced high strength concrete columns.The maximum compressive strain for concrete was found to be in the range of 0.0028 to 0.0036 in compressive block, and it can be considered that ultimate strain of concrete, 0.003, can provide a rational results in the determination of reinforced high strength concrete columns.