Cyclic response of hammer-head strap cladding-to-structure connections used in RC precast building

• Recent Italian earthquakes revealed inadequacy of the cladding-to-structure connections.
• Several cyclic tests on the hammer-head strap cladding connection were performed.
• The connection was tested in the plane of the panel.
• The failure mechanism was explained analytically.
• Macro model of the hammer-head strap connections was proposed.

During the recent earthquakes in the Emilia-Romagna region of Italy, the cladding-to-structure connections which were installed in industrial precast buildings did not perform as had been expected in their design. According to the findings of some field reconnaissance reports, in several precast buildings collapse of cladding panels occurred. This indicated the need for new research and improvements in the design and execution of such connections. In this study the cyclic response of a cladding-to-structure connections which is most commonly used in the current European design practice of precast buildings was experimentally and analytically investigated. Such connections consist of cold-formed or hot-rolled channels and hammer-head straps. They provide the out-of-plane restraint at the top corners of vertical or horizontal panels. Up until now no information has been available, in the existing literature, about the cyclic response of such connections in the plane of the cladding panels. The results of the performed experimental studies were used to develop reliable numerical models of typical connections, and to define appropriate procedures for the safe design of in-use connections.