Experimental assessment for non-monolithic slab-column connections

Abstract

It is common practice to use non-monolithic connections to connect the new flat slabs to the existing columns for upgrading the stories number of the existing buildings, despite the lack of design guidelines for the non-monolithic connection. Therefore, the current study evaluated four different techniques to connect the flat slabs with columns non-monolithically. The four systems were transferring shear force by shear dowels, transferring shear force and moment by welding dowels with the main flexural reinforcement, transferring shear force by steel bracket, and transferring shear force by concrete key-lock. An experimental study was conducted for five full-scale specimens tested under centric monotonic load and the results were compared to different codes’ expected capacities. Results showed that the four proposed techniques enhanced the punching shear capacity of the flat-slab. Moreover, the codes’ comparisons illustrated that the design codes had more reliable predictions for the monolithic connections rather than the non-monolithic ones.

Keywords

• Non-monolithic connection
• Shear dowel
• Steel bracket
• Key lock
• Shear-head systems
• And punching shear