Seismic Pushover Analysis of Global Emulative Response of Precast Reinforced Concrete Frames with Dextra Groutec Couplers

Abstract

The effects of Dextra Groutec couplers on the global performance of precast reinforced concrete frames are investigated by comparing the performance criteria of conventional RC structures to that of the said structures such that precast elements are connected end-to-end using these couplers. As couplers provide continuity of the reinforcement, precast elements that are connected using this mechanism can perform as a unit, and the entire structural system can be considered emulative as long as the structural performance is comparable to that of the conventionally designed cast-in-place. Dextra couplers inherently have lower strain compared to reinforcing rebar, affecting the global performance of a structure if placed within critical regions such as near the beam-column connection. The present study is conducted therefore to perform a comparative study to determine the effect of these couplers on the emulative behavior of the precast frames to the cast-in-place frames by considering the following factors: Coupler location, Dextra Groutec Coupler size and length, and the story height of the frame. Static pushover analysis of 30 models is carried out using the finite element software, Seismostruct. Pushover curves are compared based on the three criteria such as global ultimate displacement, displacement ductility, and energy dissipation. The results revealed that the Dextra Groutec Couplers reduce the capacity of the precast frame according to the three performance criteria. Hybrid configuration, where the bottom part is CIP and the upper part is precast connected by couplers is found to be the most viable option to obtain an emulative response. The longer and bigger Dextra Groutec coupler, S28 also manifested more inferior performance compared to S25. Lastly, the height of the structure is not a strong factor in the emulative response except for the hybrid and coupler placed at D distance away from the joint face configurations.