The out-of-plane behaviour of wall panels reinforced with Titanium rods

Titanium has exceptional durability, high specific strength, low thermal expansion and its cost has reduced significantly over the last decades. Important requirements in masonry conservation are the durability of the reinforcement materials and the reversibility of interventions: the use of titanium rods in combination with inorganic matrices meets these requirements and has recently sparked the interest of researchers. Since 2000s, titanium has been used to repair important masonry and archaeological monuments. Out-of-plane collapse mechanisms are common during earthquakes, especially when the level of connection between adjacent wall panels is weak. This paper presents the results of an experimental campaign on the use of titanium threaded rods to connect wall panels against out-of plane loading. Two reduced-scale brickwork structures (C shaped masonry specimens) have been assembled at the Structures laboratory at Northumbria University and reinforced with titanium rods, embedded in the horizontal mortar joints: the aim was to prevent or delay the out-of-plane mechanism of the face-loaded wall by connecting it to the return lateral walls. The structural performance of the masonry specimens under out-of-plane loading is also discussed, in terms of failure modes, deformation and load capacity. It is finally demonstrated that titanium threaded rods can be effectively used to improve the wal-to-wall level of connection and increase the masonry bending strength.