Retrofitting solution for beam-to-column connections of precast reinforced concrete industrial buildings

Precast reinforced concrete building structures are widely used in the Portuguese industrial stock and throughout Europe. Beam-to-column connections are a key component in this type of structure. However, they are also the source of significant damage, as reported in recent earthquakes. Different configurations are common, such as using a dowel, neoprene or just assuming a concrete-to-concrete interface. Both are characterized by a low deformation and strength capacity, presenting a significant vulnerability against seismic actions. Based on this motivation, a novel low-cost and easy-to-apply retrofit connection is herein proposed to reduce this vulnerability. Shear tests were performed to compare the performance of a retrofitted connection with the as-built configuration (i.e. concrete-neoprene interface). The experimental tests showed a good performance of the proposed retrofit solution, emphasizing the importance of this solution in frictional connections to control horizontal displacements. With the use of this solution, it was possible to overcome the resistance obtained in the connections with dowels in the most vulnerable direction, obtaining a 49% increase in the lateral resistance in the most vulnerable direction (loss of support of the beam on the column) concerning that which was verified in the friction-only connection.