BEHAVIOUR OF REINFORCED CONCRETE FLEXURAL SECTION UNDER CHANGING AXIAL LOAD.

In this paper, the effect of changing axial load on the behaviour of reinforced concrete flexural section is described with the results given by beam tests and computer-based analysis. It can be shown that the ordinary interaction diagram may be no longer valid as a failure criteria for flexural sections provided that the axial force or eccentricity changes its magnitude during the loading process. Moreover, the moment-curvature relationships are quite different from the one with constant axial force which are usually assumed in the elastoplastic analysis of dynamically loaded structures. With no consideration of the effect of changing axial load, the result obtained may deviate quite an amount from the actual condition and be on the unsafe side.