effects of mechanical coupler on cyclic behavior of wet connection in precast concrete frame

Too many efforts have been made to study the structural behavior of precast concrete momentresisting connections subjected to seismic excitations. mechanical reinforcement couplers (mrcs) are one of the main solutions for enhancing the ductility and energy absorption in the precast connection zone. the main novelty of this research is to propose an efficient precast connection using mrcs and grout. the current paper is attempted to explore the effects of the mrcs on the precast concrete connection cyclic load protocols. mrc connection is comprised of an innovative detailing for joining the reinforcement bars using couplers and the castinplace concrete was used to construct the connection zone. several test specimens with various couplers array were prepared to a comprehensive survey on the seismic behavior of the connection zone. the displacement control procedure of the test program was simulated in the abaqus software. the numerical and experimental results are analyzed to evaluate the moment carrying capacity, energy dissipation, and ductility variations. the differences of failure modes of the monolithic and new precast connection were investigated by detection of the crack propagation procedure through the test monitoring and simulation visualization. the test results of the mrcequipped specimens were compared with those of numerical models. both numerical simulation and test program leads to same results which demonstrated that the moment carrying capacity and energy dissipation are significantly improved. the crack propagation pattern in the monolithic sample was different from the precast specimens