Experimental research on seismic performance of dry-wet combined precast concrete beam-to-column connections

Abstract

In order to enhance on-site assembly efficiency and construction organization flexibility, a new type of dry-wet combined precast concrete beam-column connection was proposed. The prefabricated beams and columns were joined together using local post-tensioned tendons to create a temporary frame structure with dry connections. Subsequently, the wet connections between the prefabricated beams and slabs were established by pouring cast-in-place top concrete. A monolithic connection and four full-scale precast connections were subjected to reversal cyclic loading, with each designed incorporating distinct types of post-tensioned (PT) tendons, bonding conditions, and grouting materials. The test results indicate that the new connection exhibits flexural failure at the beam ends. In comparison to cast-in-place connections, it demonstrates enhanced deformation capacity, comparable ductility, higher stiffness, and reduced energy dissipation due to slippage of the PT tendons and steel bars. However, the viscous damping exceeds 15 %, thereby satisfying the seismic resistance requirements. The high-strength mortar grouting material satisfactorily fulfills the anchoring requirements of steel bars within the corrugated steel ducts, whereas the prestressed grouting material falls short in this regard. The overall performance of the new connection can be further enhanced by improving the grouting material and implementing local unbonded measures.