Reinforced Concrete Beam-Column Connection

Recent research on the interaction of flexural, shear and truss action and a recognition of the increasing use of high tensile strain-hardening reinforcement, prompted this experimental reconsideration of the behavior of the critical beam section at the beam-column connection. In addition to a control test, six different systems, ranging from a point-loaded simple beam to a two-span continuous system incorporating both column and column load, were tested in each group of experimental models. Proportions of tension reinforcement and tie spacing constitute the variables for the different groups of models tested. The experimental results demonstrate that the column and its loading have a significant influence on the postyield behavior of the beam critical section. Models other than the two-span system which incorporates both the column and its loading, yield nonconservative values for inelastic rotation. It is demonstrated that any simply supported system is an unacceptable quantitative model of the beam-support section. Some of the implications of using strain-hardening reinforcement are also outlined.