Experimental investigation of hybrid mechanical joints for L-shaped columns replacing conventional grouted sleeve connections

Abstract

Hybrid mechanical joints with laminated metal plates replacing conventional grouted sleeve connections for irregularly shaped columns were proposed. Interior bolts were implemented in the metal plates to provide a structural capacity similar to that of monolithic columns. Based on this study, the use of a sufficient number of interior bolts rather than thicker plates is recommended for irregularly shaped precast columns. An experimental investigation of “L”-shaped precast concrete column joints with laminated mechanical plates for fully and partially restrained moment connections was performed. In the proposed connections, a pair of steel plates with sufficient stiffness was used to enable axial loads and the moment to be transferred at the joints. High-strength bolts connecting two precast column components offered a partially or fully restrained moment connection. The structural behavior of the irregular columns with mechanical joints was evaluated experimentally. This study demonstrated how the rebar and steel sections were activated, contributing to the flexural capacity of the metal plates. The precast columns with L-shaped sections in this study fit inside the corners of the walls in residential buildings, replacing rectangular columns that do not fit at the corners.