DUCTILITY OF HIGH STRENGTH REINFORCED CONCRETE COLUMNS

Abstract

Seismic-resistant design of reinforced ductile frame buildings provides a relative condition of a strong column and weak beam at any junction. The intent is to encourage hinging in the beams rather than in the columns. However, building performance during major earthquakes and results of analysis indicate that hinging can form in columns. Therefore, the possibility of plastic hinge formation at column ends demands that building columns in seismic areas have sufficient curvature ductility. During last two decades, the use of high-strength has become widespread adding another dimension to the design problem. The equations are that exist in the current design codes f ACI 318-95, CAN3-A-23.3-M94, NZS3101:1995, and IS 13920:1993] were originally derived based on experimental results in which normal strength concrete was used. The confinement index and ductility parameter (I10) values were computed for concentric loaded columns. The confinement index and curvature ductility factor were computed for combined loading. Performing the regression analysis for these above relation an equation was developed. The design of high-strength columns as per IS code provisions, and develop a stress-strain curves and strain ductility is calculated using Legeron& Paultre stress-strain model.