RC Beam-Column Joints as Membrane Elements: An Application of MCFT

This paper addresses the evaluation of resistance of Reinforced Concrete (RC) beam-column joints by applying the Modified Compression Field Theory (MCFT). First, non-linear FEM analysis are used to discuss the stress field of the joint panel when the beam-column sub-assemblage is subjected to seismic loading. Benchmarks are considered from literature to validate the numerical models. Second, domain reduction is made by assimilating the joint panel to an isolated RC membrane subjected to shear and compressive stresses. Third, MCFT is applied to the reduced joint panel by using the freeware software Membrane 2000, developed at the University of Toronto. Finally, the obtained results are compared both to the first and second Level of Approximation design methods, to evaluate the joint shear strength, recently proposed by Fardis and included in the draft of the fib Model Code 2020.