Seismic performance and retrofit of precast concrete grouted sleeve connections

The paper investigates the suitability of grouted sleeve connections as column-to-foundation connections for precast concrete structures in seismic regions. Although grouted sleeves are commonly used, the typical advantages from this connection have not been fully addressed in the literature. Experiments on the cyclic behavior of column-tofoundation subassemblies compared the response of grouted sleeve connections with cast-in-place and pocket-foundation connections. The results demonstrate that grouted sleeves ensure a ductility and energy dissipation capacity similar to those of traditional connections. The confinement provided by the grouted sleeves inhibits buckling of the longitudinal reinforcement and increases the compressive strength of the grout. As a consequence, the damage associated with this kind of connection is localized to the column base, allowing easier postseismic column repair compared with traditional connections. The comparison of the experimental response of a grouted sleeve connection with partly unbonded reinforcement within the sleeves and the same specimen after retrofitting is also included.