Seismic performance of concrete beams with ends embedded with perforated H-shaped steel and reinforced by engineered cementitious composite

Abstract

To shift the formation of plastic hinges away from beam–column joints and reduce the number of cracks at beam ends, a novel beam in which the ends were embedded with perforated H-shaped steel and reinforced with engineered cementitious composite (ECC) was proposed. Low-cycle reciprocating loading tests were performed on four concrete beams with different structural forms at their ends. The seismic performance of the specimens was evaluated through the analysis of the responses, such as skeleton curves, ductility index, stiffness degradation, energy dissipation capacity, and strain. Some parameters, such as shear span ratio, spacing of transverse rebars, insertion depth of perforated H-shaped steel, and ECC transition section length, were analyzed by the validated finite element (FE) models. In addition, a method for calculating the shear strength capacity of the novel beams under low-cycle reciprocating loads based on the truss–arch model was proposed. The results indicate that the ECC improves the seismic performance, and the embedment of perforated H-shaped steel in the beam ends significantly enhances the bearing capacity and shifts the plastic hinges away from the beams ends; although the ductility is reduced, the novel beams can satisfy the minimum seismic performance requirements of frame structures. Compared with the test and FE results, the theoretical equations exhibit good computational accuracy.