Behavior of shear deficient reinforced concrete columns jacketed with engineering cementitious composite concrete for seismic loads

This study focuses on treating the lack of shear resistance of columns exposed to axial and lateral force, such as earthquake and wind loads. The original columns were strengthened using Engineered cementitious composite ECC jackets, which are characterized by high plastic energy dissipation capability, and a mechanism that allows for the development of multiple tensile microcracks, high tensile resistance, and high hardening strain in tension, using two types of ECC, coated and uncoated fibers. This study bases on simulation and finite element analysis of 40 retrofitted models of experimental columns using the ABAQUS software under conditions similar to those that occurred in the laboratory, by utilizing concrete damage plasticity model to represent concrete behavior under different conditions. The stress-strain relationship and constitutive models in compression and tension have been calibrated. The finite element verification was implemented for all experimental specimens, which exhibit high identical behavior with the tested columns. All models of strengthened specimens with Engineered cementitious composite (ECC) exhibit an increase in lateral load capacity as well as a distinct increasing in ductility that change the sudden shear failure to flexural failure and high enhancement in total and plastic dissipation energy compared with the original experimental columns. The ECC demonstrate excellent compatibility with steel reinforcement and large ability to compensate for the deficiency of shear reinforcement.