High‐Strength RC Connections Subjected to Inelastic Cyclic Loading

The experimental results from reversed cyclic loading tests on 12 corner-reinforced concrete beam-column subassemblies are presented. The primary variables were the concrete compressive strength, ranging between 8.1 and 13.6 ksi (55.8 and 93.8 MPa); the joint shear stress, which was either 1,100 or 1,400 psi (7.6 or 9.7 MPa); and the joint transverse reinforcement, which consisted of either four or six sets of hoops and ties placed within the depth of the joint. The provided joint reinforcement was lower than that obtained by inserting the higher concrete-compressive-strength values into the current recommendations. A small axial load was applied to the column portion of the subassembly and held constant during the test. The free end of the beam was subjected to cyclic displacements representing a wide range from elastic to severe inelastic loading. It is concluded that in spite of the brittle nature of plain high-strength concrete, properly detailed frames constructed with high-strength concrete, exhibit ductile hysteretic response similar to those for ordinary-strength connections.