Criteria for the Localized Strengthening of Unconfined Joints

In the draft Guidelines for Reparation and Strengthening of Stractural Elanents, Curtain Walls and Partitions edited by the Department of Civil Protection and by the ReLUIS consortium in August 2009, different kinds of applications were suggested in order to improve the performances of the beam-column joint, as follows  

Increase in the capacity of the joint panel and the column top with respect to the shear force exerted by curtain walls 

The shear force exerted by the curtain wall can cause relevant damages to the joint, which, depending on the starting configurations and on the cold shut section, may show a cross-crack on the joint panel (Fig. 5.1 Oa), which is a semihorizontal crack close to the section joining the column and the joint panel (Fig. 5.10b), or, again, a failure due to cross-cracking at the column head). 

In order to evaluate the force deriving from the application of this mechanism, reference is made, in a simplified fashion, to the so-called equivalent punch  

5 Strengthening of Reinforced and Prestressed Reinforced Concrete Structures 

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