Design of slender concrete column using chinese design code GB50010-2010

This project is on the study of slender concrete columns subjected to sustained short-term axial load and uniaxial bending with eccentricities at the ends, focus will be on the design approaches proposed in Chinese design code GB50010-2010. In order to make a better evaluation of this code, 2 design codes, i.e. American Concrete Institute ACI318-11 and Indian design code IS456:2000 will also be discussed and compared. Total of 150 columns which were tested by other researchers in the past have been selected for the analysis. Their eccentricity to depth ratios e/h range from 0 to 0.75, length to depth ratios L/h range from 14.697 to 50, percentages of reinforcements As/(bh) range from 0.8884% to 5.24%, actual concrete strengths fcu range from 16.7MPa to 106.7MPa, and actual yield strengths of steels fy range from 206MPa to 625MPa. Data analyses reveal that loading capacity of slender column decreases with the increase of e/h, and the reduction of strength tends to be lesser for higher e/h; slender column tends to have less loading capacity with the increase of L/h, and the reduction of strength is lesser for high L/h; slender concrete column can be strengthened by installing more reinforcements, i.e. higher percentage of reinforcement; last but not least, use of higher strength concrete and steel result in a stronger slender concrete column. Results show that ACI318-11 is the most conservative design code for slender concrete columns with an average factor of safety of 2.2, while both IS456:2000 and GB50010-2010 provide safe and close predictions with average factor of safety of 1.7. GB50010-2010 is found to be unconservative under certain conditions, such as being subjected to high eccentricity, high slenderness etc. On the other hand, those columns having initial eccentricity less than the minimum eccentricity prescribed in this code are not recommended to be designed by GB50010-2010 due to its over prediction. With the more and more popular use of slender concrete columns, it is strongly recommended that more researches and experiments shall be carried out so as to better study the behaviors and loading capacities of slender concrete columns under different conditions. Regular reviews and amendments of slender concrete column design in GB50010-2010 shall be made by professional bodies if necessaryBachelor of Engineering (Civil