Reinforced concrete columns of variable cross section
The results of a series of 19 full scale tests carried out on pin-ended reinforced concrete columns are reported. The columns tested had either tapered rectangular sections along the length or octagonal cross sections. All columns, except the last 6, were subjected to uniaxial eccentricities at one of the ends (the stronger end), and a nominally concentric load at the other end. For the case of the last six columns the loading applied at the stronger end was biaxially eccentric. For each of these tests, a complete set of measurements, covering the entire range of loading, are reported. The test results are compared with the analytical results produced by the program VAR OIS, and the design strengths predicted by the Limit State Code for Bridges BS5400: Part 4 . The thesis also includes a onarvey of published 'Literature on reinforced concrete columns, covering mainly the period from 1955 to 1981. The available information has been reviewed under three headings : predominantly theoretical research, methods of design, and tests on reinforced concrete columns. Most of the test data available on slender reinforced concrete columns, have been used to verify a computer program VAROOLS, which was originally written for composite columns, and had been verified for that type of application, but is also suitable for slender reinforced concrete columns. The comparisons show that the program predicts the ultimate strength safely in almost all cases. A new method of design for slender reinforced concrete columns with uniform and tapered cross sections is developed and design charts and worked example are presented. The method is shown to be simple and easy to be used and when compared with test results a good agreement was obtained.