| Title |
A Study on the Bi-axial Buckling Behavior of Reinforced Concrete Columns |
| Abstract |
Recently, there are useful to utilize the high-strength concrete, for buildings in the world, the reinforced concrete colunm is slender and long, step by step.As most of the study for columns have been carried out analytically by solving the governing differential equation of columns, the prediction of behavior of columns is almost impossible when the columns exist as a part of complex structure.To overcome this shortcoming the layered method is employed, because the stress-strain history can not be considered by the nonlayered method. Also, displacement control method is adapted to analyze the strain-softening behavior of columns.To analyze the effects of compressive strength of concrete and longitudinal steel ratio on buckling behavior of columns, 36 tied reinforced concrete columns with hinged ends were tested.The 100mm square cross section was used and the distance of eccentricity was 10mm. The compressive strngths of column specimens with slenderness ratiosof 15, 30 and 50 were 202, 548 and 793kg/cm2 respectively. The longitudinal steel ratio of columns with bending about a diagonal section and about a principal axis were 2.85%(4-D10).The ratio of ultimate load capacity to that of short column with the same eccentricity was much decreased at high slenderness ratio with increasing the compressive strength of concrete.And the lateral displacement of slender column at the ultimate load was decreased as the strength was increased. These are due to that at high slenderness ratio, thd load capacity and behavior of column are affected by flexural rigidity.And it was also found that for the same quantity of confining steel and level of axial load, there is little difference between the flexural strength fot longitudianl steel ratio of columns with bending about a diagonal section and for bending about principal axis. |