Experimental study on fastener strengthened masonry t-wall

Recent earthquakes have highlighted the vulnerability of unreinforced masonry buildings, as their structural integrity is often compromised by weak connections between walls. Post-installed bonded fasteners have become a popular, cost-effective retrofitting technique, yet there is a significant lack of research and clear design guidelines for their applications. To address this issue, an experimental study was conducted on four full-scale T-shaped masonry wall specimens, intentionally built with weak connections to replicate common practice. The specimens were first tested under monotonic out-of-plane loading without reinforcement and subsequently retrofitted with a bonded fastener system (rebars and a hybrid adhesive) and subjected to cyclic loading. The study investigated the effect of two key design parameters: the embedment depth (85 cm vs. 65 cm) and the number of connectors (8, 3, or 2 rebars). The results showed that, although all retrofitted configurations achieved a similar range for the maximum horizontal load, only the higher number of fasteners guaranteed the necessary monolithic behavior that dictates the overall performance and failure mode.