Moment curvature relation of Reinforced Concrete T beam sections Numerical and Experimental studies

Abstract

A simple algorithm is proposed to develop a nonlinear moment-curvature relation for Reinforced Concrete (RC) T-beam sections using nonlinear material models. The flange in the beam adds to the complexity of analysis compared to rectangular beam sections. This algorithm has been validated by laboratory testing of simply supported flanged beam specimens, subjected to two-point loading. The load- deflection data obtained from the experiments is converted to a moment-curvature relation for the section applying simple bending theory. The results predicted numerically by the proposed algorithm are found to be in good agreement with the experimental data. The algorithm developed can be used to generate the load-deflection curve of an RC T-beam subject to any given loading. A portion of continuous slab integrally connected to the beam serves as flange and the supporting beam as web. The flexural capacity of such sections can be enhanced when the flanges are in compression. The web helps in resisting shear stresses. The moment-curvature relation is obtained by carrying out sectional analysis of RC T-beam section. In this analysis, different cases are considered depending on the position of the neutral axis (6). Testing of three T-beams has been carried out in the laboratory. These beams are loaded symmetrically at two points to simulate pure flexure. Load- deflection data obtained from these tests is used to generate moment-curvature relation using theory of simple bending. The results generated by numerical algorithm are validated with these experimental results. The behavior of the beams is studied for variation in depth of flange and tensile reinforcement. The nonlinear sectional analysis for these RC T-beams is explained in the next section.