STUDY OF BEHAVIOR OF REINFORCED CONCRETE PORTAL FRAMES UNDER REPEATED LOADING

Abstract

The behaviour of reinforced concrete portal frames under nonreversible repeated loading is presented. Experimental work consists of four portal frames, one tested under proportional loading and three under repeated nonreversible loading. In order to determine the plastic moment capacity pie-Des were cut from frames tested under repeated loading and another. test specimen having same details are tested as beams under central concentrated load till failure. It is found that repeated non-reversible loading does not significantly affect the ultimate strength of reinforced concrete frames or beams. The stiffness of the frame's as well as individual members is however reduced to an appreciable extent. The reduction in stiffness is more at lower values of repeated nonreversible load. Beyond the working load the horizontal deflection of frames under repeated nonreversible loading is about 300A larger than that under proportional loading.