Load and resistance factor design of composite columns

Test capacities of composite concrete-encased steel profile and concrete-filled tube columns and beam-columns are compared with predictions of the design model of the American Institute of Steel Construction Load and Resistance Factor Design criteria. Some 300 tests were examined. It was found that the design model is conservative, but that the scatter of the tests with respect to the AISC design model is also high. A first-order second-moment reliability study revealed that the concrete-encased members exceeded the target reliability index in the design specification, but that the concrete-filled tubes had an inadequate reliability index when compared to the target value. It is recommended that both a better design model and further tests are needed to arrive at satisfactory design criteria. Copyright